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Cleghorn, Simon John Charles. "Electrocatalytic hydrogenation at palladium electrodes". Thesis, University of Southampton, 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.332771.
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Zaczek, Christoph. "Electrolysis of Palladium in Heavy Water". PDXScholar, 1995. https://pdxscholar.library.pdx.edu/open_access_etds/5051.
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Following several reports in the past few years about compositional changes on palladium used as a cathode in heavy water electrolysis, the purpose of this research project was to reproduce this results. Two experiments were performed using two cells connected in series, an experimental cell and a control cell. Both experiments used platinum anodes, the experimental cell had a palladium cathode and the control cell had a platinum cathode. The electrolyte was D20 with H2S04. Radiation was monitored during both experiments. Also temperature and voltage were recorded for both experiments, to allow statements about excess heat of the experimental cell in comparison to the control cell. Both experiments had problems with unequal electrolyte loss, so that no statements about excess heat could be made. No significant radiation was detected in either experiment. Also no compositional changes on the palladium cathodes after electrolysis in both experiments could be detected. Impurities in grain-shaped defects on the palladium cathode before the experiment were found in either experiment. These impurities were Si, Ca, 0, and sometimes also Mg, Na and Fe. Localized findings of Au and Pt, in a distance of 1-2μm to each other, were made on the palladium cathode from the second experiment before electrolysis. Spot, grain-shaped and longitudinal defects were found on the original palladium foil used for the cathodes in either experiment No evidence for fusion, or any other nuclear reaction in the crystal lattice of palladium, used as cathode in heavy water electrolysis, was observed.
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Kurpiewski, John Paul. "Electrospun carbon nanofiber electrodes decorated with palladium metal nanoparticles : fabrication and characterization". Thesis, Massachusetts Institute of Technology, 2005. http://hdl.handle.net/1721.1/32370.
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Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2005.Includes bibliographical references (p. 126-128).
A new method was investigated to produce a novel oxygen reduction electrode comprised of carbon nanofibers for use in polymer electrolyte membrane (PEM) fuel cells and metal-air batteries. The process involved electrospinning a solution of polymer (polyacrylonitrile), noble metal salt (palladium (II) acetate), and organic solvent (n,n- dimethylformamide) to fabricate a porous, non-woven, free-standing nanofiber mesh. Through experimentation with multiple variables, the optimal electrospinning parameters were quantified. Post-process heating of the electrospun nanofibers included stabilization in air environment at 280⁰C for 2 hours, followed by carbonization in grade 5.0 argon environment to temperatures between 800 and 1100⁰ C for times varying between 1 minute to 1.5 hours. The carbonization step served the purpose of converting insulating polymer into conductive amorphous carbon and precipitating nanoparticles of palladium in a homogeneous distribution throughout the electrode. The electrode was characterized using scanning electron microscopy (SEM), x-ray diffraction (XRD), transmission electron microscopy (TEM), microprobe station, and x-ray adsorption near edge structure (XANES). Electrochemical performance was characterized using cyclic voltammetry (CV), rotating disk electrode (RDE), and testing in a PEM fuel cell. It was demonstrated that palladium crystal size and particle size increased with heat treatment time and temperature. Lower concentrations of PAN in solution had the effect of thinner nanofibers (100-400nm diameters), which led to faster particle growth.
(cont.) Particle sizes were often distributed in a bimodal Gaussian distribution, centered around values on the order of lOnm and 100nm. In-situ TEM allowed for particle formation and growth to be investigated. Cross-sectional TEM showed that particle nucleation occurred within the fibers. Electrodes were spun as thin as 7 microns, and contained no significant amounts of graphite or palladium oxide. Electrochemical surface area was 7.17 m²/g catalyst, and the performance was comparable to commercially available E-TEK electrodes on a catalyst cost per power basis. It was shown platinum salts worked well in the process, allowing platinum electrodes to be fabricated.
by John Paul Kurpiewski.
S.M.
4
Ledezma, Razcon Eugenio A. "MODELING OF THE BIOELECTRIC SYSTEM FORMED BY PALLADIUM AND CARBON ELECTRODES INSERTED IN COTTON (GOSSYPIUM HIRSUTUM) PLANTS". Thesis, The University of Arizona, 1985. http://hdl.handle.net/10150/275289.
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Silwana, Bongiwe. "Graphene supported antimony nanoparticles on carbon electrodes for stripping analysis of environmental samples". University of the Western Cape, 2015. http://hdl.handle.net/11394/5141.
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>Magister Scientiae - MScPlatinum Group Metals (PGMs), particularly palladium (Pd), platinum (Pt) and rhodium (Rh) have been identified as pollutants in the environment due to their increased use in catalytic converters and mining in South Africa (as well as worldwide). Joining the continuous efforts to alleviate this dilemma, a new electrochemical sensor based on a nanoparticle film transducer has been developed to assess the level of these metals in the environment. The main goal of this study was to exploit the capabilities of nanostructured material for the development and application of an adsorptive stripping voltammetric method for reliable quantification of PGMs in environmental samples. In the study reported in this thesis, glassy carbon electrode (GCE) and screen-printed carbon electrode (SPCE) surfaces were modified with conducting films of nanostructured reduced graphene oxide-antimony nanoparticles (rGO-SbNPs) for application as electrochemical sensors. The rGO-SbNPs nanocomposite was prepared by Hummer`s synthesis of antimony nanoparticles in reaction medium containing reduced graphene oxide. Sensors were constructed by drop coating of the surfaces of the carbon electrodes with rGO-SbNPs films followed by air-drying. The nanocomposite material was characterised by: scanning and transmission electron miscroscopies; FTIR, UV-Vis and Ramanspectrosocopies; dc voltammetry; and electrochemical impedance spectroscopy. The real surface area of both electrodes were studied and estimated to be 1.66 × 10⁶ mol cm⁻² and 4.09 × 10³ mol cm⁻² for SPCE/rGO-SbNPs and GCE/rGO-SbNPs, respectively. The film thickness was also evaluated and estimated to be 0.36 cm and 1.69 × 10⁻⁶ cm for SPCE/rGO-SbNPs and GCE/rGO-SbNPs, respectively. Referring to these results, the SPCE/rGO-SbNPs sensor had a better sensitivity than the GCE/rGO-SbNPs sensor. The electroanalytical properties of the PGMs were first studied by cyclic voltammetry followed by indepth stripping voltammetric analysis. The development of the stripping voltammetry methodology involved the optimisation of experimental conditions such as selection of adequate supporting electrolyte, choice of pH and /or concentration of supporting electrolytes, deposition potential, deposition time, stirring conditions. The detection of Pd(II), Pt(II) and Rh(III) in environmental samples were performed SPCE/rGO-SbNPs and GCE/rGO-SbNPs at the optimised experimental conditions For the GCE/rGO-SbNPs sensor, the detection limit was found to be 0.45, 0.49 and 0.49 pg L⁻¹ (S/N = 3) for Pd(II), Pt(II) and Rh(III), respectively. For the SPCE/rGO-SbNPs sensor, the detection limit was found to be 0.42, 0.26 and 0.34 pg L⁻¹ (S/N = 3) for Pd(II), Pt(II) and Rh(III), respectively. The proposed adsorptive differential pulse cathodic stripping voltammetric (AdDPCSV) method was found to be sensitive, accurate, precise, fast and robust for the determination of PGMs in soil and dust samples. The simultaneous determination of PGMs was also investigated with promising results obtained. The AdDPCSV sensor performance was compared with that of inductive coupled plasma mass spectroscopy (ICP-MS) for the determination of PGM ions in soil and dust samples. It was found that though the metals could be determined by ICP-MS technique, it was limited from the standpoints of sensitivity, ease of operation and versatility compared to the AdDPCSV sensor. This study has show cased the successful construction and application of novel SPCE/rGO-SbNPs and GCE/rGO-SbNPs AdDPCSV sensors forthe determination of PGMs in environmental samples (specifically roadside dust and soil samples). The study provides a promising analytical tool for monitoring PGMs pollutants that are produced by automobiles and transported in the environment.
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Serrapede, Mara. "Nanostructured palladium hydride electrodes : from the potentiometric mode in SECM to the measure of local pH during carbonation". Thesis, University of Southampton, 2014. https://eprints.soton.ac.uk/366986/.
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The detection of local variations of the proton activity is of interest in many fields such as corrosion, sedimentology, biology and electrochemistry. Using nanostructured palladium microelectrodes Imokawa et al. fabricated for the first time a reliable and miniaturized sensor with high accuracy and reproducibility of the potentiometric-pH response. In absence of oxygen, the nanostructured palladium hydride tips are sensitive only to the activity of the protons close to their local environment and they have an almost Nernstian theoretical response with a slope of -58.7 mV/pH (25C) from pH 2 to 14. In the bulk, the lifetime of the palladium hydride sensor is 60 times longer when the solution is saturated with argon than with oxygen. Besides, the open circuit potential (OCP) recorded during the discharge of the hydride is more positive in an oxygenated solution. To unravel the influence of oxygen on the potentiometric response of these tips, we carried out a series of potentiometric and amperometric scanning electrochemical microscopy (SECM) experiments over a range of tip-substrate distances against an inert substrate. Potentiometric SECM experiments in aerated solutions demonstrate that the duration of the hydrogen discharge and tip potential depend on the tip-substrate distance: the closer the tip is to an inert substrate, the longer the lifetime of the sensor is, and the more cathodic the open circuit potentials are. Linear sweep voltammetry (LSV) near the OCP values reveals that the polarization resistance decreases when the tip approaches the substrate. These trends are confirmed by Tafel plots recorded over a range of tip-substrate distances. Potentiometric and amperometric measurements are found to be in good agreement. These results can be analysed in terms of a mixed potential theory as used in corrosion. They reveal that in the potentiometric mode, despite being held at zero current, the tips promote the reduction of oxygen which in turns leads to the rapid discharge of hydrogen from the palladium hydride. The closer the tip is to the substrate, the smaller is the flux of oxygen, the longer is the duration of the discharge and the more negative is the OCP. This dissertation will therefore show that even in a potentiometric SECM experiment where the tip is supposed to be a passive probe, hindered diffusion can affect the tip potential and produce a dependence on the tip-substrate distance. In aerated solutions, a simple correction can be made to bulk experiments. In this study the exceptional potentiometric properties of pH microprobes made with nanostructured palladium hydride microelectrodes are reported to demonstrate their application by monitoring pH variations resulting from a reaction confined in a porous medium. Their properties were validated by detecting pH transients during the carbonation of Ca(OH)2 within a fibrous mesh. Experimental pHs recorded in situ were in excellent agreement with theoretical calculations for the CO2 partial pressures considered. Results also showed that the electrodes were sufficiently sensitive to differentiate between the formation of vaterite and calcite, two polymorphs of CaCO3. These nanostructured microelectrodes are uniquely suited to the determination of pH in highly alkaline solutions, particularly those arising from interfacial reactions at solid and porous surfaces.
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Clymer, John Owen 1960. "Development of a palladium electrode oxygen sensor". Thesis, The University of Arizona, 1992. http://hdl.handle.net/10150/291974.
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This thesis investigates the nature of the potential variations in an electrochemical cell. The cell consists of palladium electrodes immersed in a phosphate buffer electrolyte with a Ag/AgCl double junction reference electrode. The relaxation response of the electrodes to an applied potential is examined and current-potential curves ("voltammograms") are generated by plotting the current flowing through an external circuit versus the measured electrode potential. These graphs show regions of hydrogen adsorption/desorption and areas of oxygen adsorption/desorption. The response of the cell to both nitrogen and oxygen "sparging," a technique that alters the gas concentration of the electrolyte, is also studied. Under these conditions, the potential fluctuates in a predictable manner. In addition, the voltage variations of palladium electrodes inserted into stems of tomato plants is investigated to compare results. The goal of this project is to provide evidence supporting the "Oxygen Hypothesis."
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Shi, Zhongliang 1965. "Electroless deposited palladium membranes and nanowires". Thesis, McGill University, 2007. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=111872.
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Hydrogen is considered to be the fuel of the future as it is clean and abundant. Together with the rapidly developing fuel cell technology, it can sustain an environmentally sound and efficient energy supply system. Developing the technologies of palladium-based membrane for hydrogen separation and palladium nanostructured materials for hydrogen sensing and hydrogenation catalysts makes the "hydrogen economy" possible. This is because these technologies will allow for commercially viable production of comparatively cheap and high-quality hydrogen, and safety of its application. Based on the market requirements and interest in the development of a hydrogen economy, the purposes of this thesis are to develop thin palladium membrane for hydrogen separation and to explore an economic method for the synthesis of palladium nanowires in potential engineering applications. The original contributions of this thesis are outlined below:The investigation of deposition progress of a palladium membrane on porous stainless steel substrate illustrates that palladium deposits will form a network structure on pore areas of the substrate surface in the initial stages. A bridge model is presented to describe the formation of a membrane. This model is confirmed from the cross-section of the deposited membranes. Based on the bridge model and the experimental measurements of palladium membranes deposited on the pore area of the substrates, the thickness of a palladium membrane deposited on 0.2 mum grade porous stainless steel substrate can be effectively controlled around 1.5∼2 mum, and the thickness of a palladium membrane deposited on 2 mum grade porous Inconel substrate can be effectively controlled around 7.5∼8 mum. Comparing the thickness and quality of palladium membranes deposited on the same substrates with the data in the literature, the thicknesses of the membranes prepared in this program are lower. The obtained result will be beneficial in the design and manufacture of suitable membranes using the electroless deposition process.
In the initial deposition stages, palladium nanoparticles cannot be deposited at the surface of the SiO2 inclusions that appear at the substrate surface. With the extension of deposition time, however, palladium nanoparticles gradually cover the SiO2 inclusions layer by layer due to the advance deposited palladium nanoparticles on the steel substrate surrounding them. The effect of the SiO2 inclusions on palladium deposits cannot be neglected when an ultra-thin membrane having the thickness similar to the size of inclusions is to be built.
The chemical reaction between phosphorus (or phosphate) and palladium at high temperature can take place. This reaction causes surface damage of the membranes. If palladium membranes are built on the porous substrates that contain phosphorus or phosphate used in the inorganic binders, they cannot be used over 550°C. This result also implies that palladium membranes cannot be employed on the work environment of phosphorus or phosphates.
Palladium nanowires are well arranged by nanoparticles at the rough stainless steel surface. The formation procedures consist of 3 stages. In the initial stage, palladium nanoparticles are aligned in ore direction, then the nanowire is assembled continuously using follow-up palladium deposits, and finally the nanowire is built smoothly and homogeneously. It is also found that palladium nanoparticles generated from the autocatalytic reaction are not wetting with the steel substrate and they are not solid and easily deformed due to the interfacial tension when they connect to each other.
Various palladium nanowire arrays possessing the morphologies of single wires, parallel and curved wires, intersections and network structures are illustrated. The results demonstrate that palladium nanowires can be built in a self-assembled manner by palladium nanoparticles in the initial deposition stages. Such self-assembled nanowires may attract engineering applications because electroless deposition process and preparation of a substrate are simple and inexpensive.
The diameter of palladium nanowires can be effectively controlled by the concentration of PdCl2 in the plating solution and deposition time. The size of palladium nanoparticles generated from the autocatalytic reaction is directly dependent on the concentration of PdCl2 in the plating solution. The higher the concentration of PdCl2 in the plating solution is, the smaller the deposited palladium nanoparticles are. The experimental results provide a controllable method for the fabrication of palladium nanowire arrays with potential engineering applications.
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Zhang, Zhehao. "Palladium Voltammetric Microelectrode as pH Sensor in an Micro Electrochemical Cell". Case Western Reserve University School of Graduate Studies / OhioLINK, 2017. http://rave.ohiolink.edu/etdc/view?acc_num=case1496862043661465.
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Tian, Bo. "Modified electroless plating technique for preparation of palladium composite membranes". Thesis, Link to the online version, 2005. http://hdl.handle.net/10019/1243.
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Lui, Nicholas Hong. "Fabrication and Characterization of a Palladium/Porous Silicon Layer". DigitalCommons@CalPoly, 2013. https://digitalcommons.calpoly.edu/theses/1094.
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When porous silicon is plated with a catalytic metal, the two materials can act together as a single entity whose electrical properties are sensitive to its environment – the sensing component of an electrochemical gas sensor. Etching pores into silicon is an electrochemical process; and which type of doped silicon used is one of its key parameters. For nearly all reported porous silicon gas sensors, the silicon has been of the p-doped variety – because p-doped porous etching is better understood and the layers that result from it are more predictable – despite n-doped silicon having potentially significant benefits in ease of fabrication and being more conducive to plating by a catalyst. This experiment is an attempt at creating a palladium plated n-doped porous silicon layer, and an examination into what differentiates this fabrication process and the layers that result from the traditional p-doped type.
The porous layers to be plated are to be the same and would ideally have properties that are a close approximation to what a functional gas sensor would require. This experiment defined a process that fabricated this “ideal” layer out of N-type, , double polished silicon wafers with a resistance of 20 Ω cm. The wafers were subjected to the anodic etching method with an HF/ethanol mixture as the electrolyte; and only two (of among many) fabrication parameters were varied: HF concentration of the electrolyte and total etching time. We find that a concentration of 12% HF (by volume) and an etching time of 6 hours result in layers most appropriate to carry into plating. The anodization current density is 15 mA cm-2. Deposition of the catalyst, palladium, is done using the electroless method by immersing the porous layer in a .001M PdCl2 aqueous bath.
Characterization of this Pd/Porous Silicon layer was done by measuring resistivity by four point probe and imaging through Scanning Electron Microscopy. It was found that layers of a maximum average of 63 ± 6% porosity were created using our fabrication method. There is evidence of palladium deposition, but it is spotty and irregular and is of no improvement despite the n-doping wafer makeup. Resistivity in well-plated regions was measured to be 7-10 Ωcm, while resistivity in regions not well-plated was measured to be 70-140 Ω cm. This is comparable to previous literature values, indicating n-silicon porous silicon can be fabricated and still have potential as a catalytic layer, should metal deposition methods improve.
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Bird, Elliott J. "Investigation of Additives for Use in Electroless Plating Solutions for Fabrication of Nanowires". BYU ScholarsArchive, 2009. https://scholarsarchive.byu.edu/etd/2125.
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This study focused on improvement of electroless plating methods by use of particular bath additives. The techniques developed here can enable us to plate very thin layers selectively on a nonconductive substrate and thus create metallized features on a nanoscale. Through the development of such bottom-up techniques this work contributes a key technology to achieving self-assembled nanocircuits. The use of additives in an electroless plating environment can modify the barriers to nucleation (or seeding) and growth. Two additives, namely 3-mercapto-1-propanesulfonic Acid (MPS) and 1,3-propanedisulfonic acid (PDS), notably increased the selectivity of electroless metallization on chemically modified surfaces, which can be used to create patterned structures. More specifically, the additives increased the growth rate of metal on an aminosilane-coated surface relative to an uncoated surface. This work includes an examination of metal layer thickness and conductivity in addition to selectivity. The layer thickness was determined through the use of atomic force microscopy on surfaces that exhibited conductivity. The conductivity of the surface metal was determined through a measurement on a four-point probe measurement. In this series of experiments, the disulfonate-containing additive PDS provided the highest nucleation density, highest conductivity and the best selectivity ratio. The palladium metal deposit on the PDS-treated surface was nearly uniform in height and its conductivity approached the bulk conductivity of palladium with a metal height of less than 30 nm. MPS-treated surfaces also provided increased nucleation density when used during the seeding step, but the resulting conductivity was less than that of the PDS treated samples. We recommend the use of PDS as an effective electroless plating additive for use in palladium electroless plating processes.
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Saini, Alpna. "An investigation of the cause of leak formation in palladium composite membranes". Link to electronic thesis, 2006. http://www.wpi.edu/Pubs/ETD/Available/etd-050406-133412/.
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Takky, Driss. "Effet de la structure moléculaire en electrocatalyse : étude mécanistique de l'oxydation des isomères du butanol en milieu aqueux sur diverses électrodes de metaux nobles". Poitiers, 1987. http://www.theses.fr/1987POIT2008.
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Alami, Mohammed. "Métallisation des polymères par le procédé "electroless" : étude XPS des étapes préalables d'activation des surfaces". Lyon 1, 1994. http://www.theses.fr/1994LYO10300.
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Le present travail porte sur la metallisation (nickelage chimique) des polymeres par le procede electroless dit encore autocatalytique et plus particulierement sur les traitements de surface prealables a cette metallisation. Cette etude, realisee dans un premier temps sur le polycarbonate, envisage successivement le traitement de surface du polymere par voie chimique et par plasma de gaz reactifs, puis le traitement mis en uvre pour rendre la surface catalytique vis-a-vis de la reaction de reduction des ions ni#2#+. Ce dernier traitement a d'abord ete realise par le processus classique a deux etapes: sensibilisation par sncl#2 puis activation par pdcl#2. Chacune des etapes precedentes a ete etudiee par xps. Les analyses correspondantes ont permis de mettre en evidence les modifications de surface du polymere a la suite des differents traitements par plasma et d'interpreter les mecanismes reactionnels mis en jeu lors de la chimisorption des ions sn#2#+ puis pd#2#+. Elles ont montre que les ions pd#2#+ etaient capables de s'adsorber directement lors d'un simple traitement par pdcl#2 sur une surface porteuse de groupements fonctionnels azotes apportes par un traitement plasma n#2 ou nh#3. Cette caracteristique a ete mise en evidence par analyse xps sur des polymeres naturellement porteurs de fonctions azotees (polyamide-polyacrylonitrile). Cette etude, essentiellement basee sur des analyses de surface par xps, a permis de mettre au point un protocole operatoire simplifie a une seule etape pour adsorber du palladium sur la surface des polymeres. Ce protocole, qui permet de s'affranchir des solutions de sncl#2 facilement oxydables, presente un interet certain pour la mise en uvre de la metallisation electroless
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Labiadh, Amor. "Etude d'un procédé d’écriture directe d'interconnexions par laser et electroless : application aux modules multipuces (MCM)". Lyon, INSA, 1994. http://www.theses.fr/1994ISAL0057.
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L' intégration à très grande échelle (VI. . SI) in"pose le développement de systèmes d'interconnexions adaptés. En effet , les boîtiers standards et les circuits imprimés limitent la densité d'intégration dégradent l'amplitude et le temps de montée de signal transnis. Le terres de prcpagation très long est la conséquence des règles de dessin et des matériaux utilisés. Ces limitations peuvent être franchies en utilisant les moodules multiples couches minces (r-o1-D) pour interconnecter les puces entre elles. La technique conventionnelle pour développer et fabriquer ces modules est la photolitho gravure. Dans le cadre de cette thèse, nous avons développé un procédé d écriture directe par laser suivi d'electroless permettant la réalisation de lignes d'interconnexions de 5 à 50 m de large. Ce procédé rapide et souple, doit permettre 1'étude et le test des modules MCM prototypes. Dans une première étape, il est foncé sur la décomposition localisée par laser d'un film mince de métalorganique. Le produit final de décomposition (métal) servira comme surface active pour la croissance du cuivre par electroless dans une seconde étape. Le choix du précurseur metalorganique s est fixé sur l'acétate de palladium qui se décompose à faible température, contient une forte proportion d'éléments métallique et n'est pas hydraté . Nous avons étudié les cinétiques de décomposition et de croissance de des deux matériaux : palladium et cuivre. Les conditions expérimentales ont été mises au point pour aboutir à des résultats fiables et reproductibles. La composition des matériaux constituant les lignes d'interconnexions, la morphologie des surface et des interfaces ont été analysés. Enfin, l'asemblage de toutes les étapes élémentaires permettant de fabriquer un niveau conducteur a été réaliséThe very large scale integration (VSLI) dictate the development of the adapted interconnection systems. Therefore, the conventional packing and the printed board (PCB) limit the integration density, degrade the amplitude and the rise of the transmitted signal. The long propagation time results from pattern rules and used materials. Those limitations can be exceded by using the thin layer multichip modules (MCM-D), to interconnect the chip ? The conventional technical to develop and fabricate those modules in the photolithography In this thesis, we have developed a process of laser direct writing followed by electroless allowing the realisation of interconnection lines of 5 to 50 m with. The fact and flexible process must allow the study and test of MCM prototypes. In the first step, it is based on the local laser decomposition of metalorganic film. The final product of decomposition will be usefull as an active surface for the electroless copper growth, in the second step. Th e choice of the metalorganic precursor is fixed on the palladium acetate that to be decomposed at lower temperature, content an important portion of metallic element ant it is not hydrated. We have studied the decomposition and growth kinetics of the two materials : palladium and copper. The experimental condition have been determined to obtain an reliable and reproducible result. The composition of the material forming the interconnection lines, the morphology of surface and interfaces have been analysed. At the end, the assembly of all elementary steps allowing the fabrication of an one conductor level has been realised
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Adeniyi, Olushola Rotimi. "Ion track modification of polyimide film for development of palladium composite membrane for hydrogen separation and purification". Thesis, University of the Western Cape, 2011. http://etd.uwc.ac.za/index.php?module=etd&action=viewtitle&id=gen8Srv25Nme4_8563_1330330939.
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South Africa s coal and platinum mineral resources are crucial resources towards creating an alternative and environmentally sustainable energy system. The beneficiation of these natural resources can help to enhance a sustainable and effective clean energy base infrastructure and further promote their exploration and exportation for economics gains. By diversification of these resources, coal and the platinum group metals (PGMs) especially palladium market can be further harnessed in the foreseeable future hence SA energy security can be guaranteed from the technological point of view. The South Africa power industry is a critical sector, and has served as a major platform in the South African socio-economic development. This sector has also been identified as a route towards an independent energy base, with global relevance through the development of membrane technologies to effectively and economically separate and purify hydrogen from the gas mixtures released during coal gasification. The South Africa power industry is a critical sector, and has served as a major platform in the SA&rsquo
s socio-economic development. This sector has also been identified as a route towards an independent energy base, with global relevance through the development of membrane technologies to effectively and economically separate and purify hydrogen from the gas mixtures released during coal gasification. Coal gasification is considered as a source of hydrogen gas and the effluent gases released during this process include hydrogen sulphide, oxides of carbon and nitrogen, hydrogen and other particulates. In developing an alternative hydrogen gas separating method, composite membrane based on organic-inorganic system is being considered since the other available methods of hydrogen separation are relatively expensive.
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Chen, Chao-Huang. "Sulfur tolerance of Pd/Au alloy membranes for hydrogen separation from coal gas". Digital WPI, 2012. https://digitalcommons.wpi.edu/etd-dissertations/63.
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This work provides a detailed characterization study on H2S poisoning of Pd and Pd/Au alloy composite membranes to obtain fundamental understandings of sulfur poisoning phenomena and preparation of sulfur tolerant membranes. The enhancement of the sulfur tolerance by alloying Pd with Au has been confirmed by both permeation test and microstructure analysis (SEM and XRD). While pure Pd membranes exhibited the permeance decline in the presence of H2S due to both sulfur adsorption and bulk Pd4S formation, Pd/Au alloy membranes showed the permeance loss merely resulted from the surface sulfur adsorption without bulk sulfide formation up to 55 ppm H2S. The XPS study confirmed that the H2S adsorption on the Pd/Au alloy surfaces was dissociative, and both surface Au and Pd sulfides were formed with the preferential Au-S bonding. The adsorption type of sulfur on the Pd/Au alloy surfaces was monolayer with a limited coverage, which increased with decreasing temperature. The permeance loss of Pd/Au membranes was essentially fully recoverable in H2, and the integrity of the membranes remained unaltered after the poisoning/recovery tests. Increasing Au composition in the Pd/Au membranes increased the sulfur tolerance. A Pd/Au alloy membrane of 16.7 wt% Au exhibited a permeance over 50% of its original value in the presence of 5 ppm H2S at 400°C, while a Pd membrane showed 85% permeance loss. The Pd/Au alloy membranes were fabricated by the Au displacement deposition, which had an empirical reaction order of 3.2 determined by the AAS. The HT-XRD study verified that the formed Pd/Au alloy layers were thermally stable up to 500°C.
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Pierson, Bruce Gregory. "Chemical reactions at the interfaces of semiconductors and catalysts with solutions: I. Tin-palladium catalysts in electroless copper plating. II. Dissolution of crystalline gallium-arsenide in solutions containing complexing agents". Diss., The University of Arizona, 1989. http://hdl.handle.net/10150/184673.
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The concentration of tin and palladium in catalysts used in electroless copper plating have been determined by Rutherford backscattering spectrometry with high energy (2-5) MeV ⁴He⁺. The tin:palladium ratio in the catalyst decreases when exposed to an alkaline solution. X-ray photoelectron spectroscopy has confirmed this result and has shown the palladium in the catalyst is present as palladium metal and the tin is present, probably as an oxidized species, to a depth of about 30 Å. Catalysts for the electroless plating of copper are obtained by the reaction of Pd(II) and Sn(II). The extent of the reaction and the concentrations of the reaction products depend on the solution conditions. Conflicting results obtained in previous investigations of tin-palladium catalysts can be explained on this basis. Single crystals of gallium arsenide (GaAs(100)) were found to dissolve in synthetic lung fluid (Gamble solution). The concentrations of arsenic and gallium in the Gamble solution as well as the arsenic:gallium ratio on the GaAs surface increased continuously as the time of exposure to the Gamble solution increased. X-ray photoelectron spectroscopic studies of the gallium arsenide surface showed that arsenic migrated to the surface and it was oxidized to a species resembling As₂O₃ and finally solubilized by the Gamble solution. The solubility of gallium was governed primarily by the formation of stable complexes with the citrate and phosphate ions in the Gamble solution. Zinc that was present in the single crystals of gallium arsenide also migrated to the surface.
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Yun, Samhun. "Fabrication of Ultrathin Palladium Composite Membranes by a New Technique and Their Application in the Ethanol Steam Reforming for H₂ Production". Diss., Virginia Tech, 2011. http://hdl.handle.net/10919/37505.
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This thesis describes a new technique for the preparation of ultrathin Pd based membranes supported on a hollow-fiber α-alumina substrate for H₂ separation. The effectiveness of the membranes is demonstrated in the ethanol steam reforming (EtOH SR) reaction in a membrane reactor (MR) for H₂ production.
The membrane preparation technique uses an electric-field to uniformly deposit Pd nanoparticle seeds on a substrate followed by deposition of Pd or Pd-Cu layers on the activated surface by electroless plating (ELP). The well distributed Pd nanoparticles allow for enhanced bonding between the selective layer and the substrate and the formation of gas tight and thermally stable Pd or Pd-Cu layers as thin as 1 µm, which is a record in the field. The best Pd membrane showed H₂ permeance as high as 5.0 × 10⁶ mol m²s⁻¹Pa⁻¹ and stable H²/N₂ selectivity of 9000 - 7000 at 733 K for 5 days. The Pd-Cu alloy membrane showed H₂ permeance of 2.5 × 10⁶ mol m⁻²s⁻¹Pa⁻¹ and H₂/N₂ selectivity of 970 at the same conditions.
The reaction studies were carried out with a Co-Na/ZnO catalyst both in a packed bed reactor (PBR) and in a MR equipped with the Pd or Pd-Cu membrane to evaluate the benefits of employing membranes. For all studies, ethanol conversion and hydrogen product yields were significantly higher in the MRs compared to the PBR. Average ethanol conversion enhancement and hydrogen molar flow enhancement were measured to be 12 % and 11 % in the Pd MR and 22 % and 19 % in the Pd-Cu MR, respectively. These enhancements of the conversion and product yield can be attributed to the shift in reaction equilibria by continuous hydrogen removal by the Pd based membranes. The comparative low enhancement in the Pd MR was found to be the result of significant contamination of Pd layer by CO or carbon compounds deposition during the reaction.
A one-dimensional modeling of the MR and the PBR was conducted using identical conditions and their performances were compared with the values obtained from the experimental study. The model was developed using a simplified power law and the predicted values matched experimental data with only minor deviations indicating that the model was capturing the essential physicochemical behavior of the system. Enhancements of ethanol conversion and hydrogen yield were observed to increase with rise in space velocity (SV), which could be explained by the increase in H₂ flux through the membranes with SV in the MRs.Ph. D.
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Akis, B. Ceylan. "Preparation of Pd-Ag/PSS composite membranes for hydrogen separation". Link to electronic thesis, 2004. http://www.wpi.edu/Pubs/ETD/Available/etd-0430104-113019.
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Ayturk, Mahmut Engin. "Synthesis, annealing strategies and in-situ characterization of thermally stable composite thin Pd/Ag alloy membranes for hydrogen separation". Worcester, Mass. : Worcester Polytechnic Institute, 2007. http://www.wpi.edu/Pubs/ETD/Available/etd-042307-012951/.
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Thesis (Ph.D.)--Worcester Polytechnic Institute.Keywords: composite Pd and Pd/Ag membranes, alloying, Pd/Ag barrier, intermetallic diffusion, bi-metal multi-layer BMML deposition, electroless plating kinetics, high temperature x-ray diffraction, aluminum hydroxide surface grading, porous sintered metal supports, hydrogen separation. Includes bibliographical references (leaves 279-296 ).
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Coulm, Jérémy. "Optimisation des traitements de surface de substrats polymères par plasma et développement de techniques de lithographie douce innovantes pour leur métallisation electroless localisée à basse et très haute résolution". Thesis, Lyon 1, 2015. http://www.theses.fr/2015LYO10034/document.
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Les dispositifs interconnectés moulés (« Molded Interconnected Devices », MID) sont constitués de supports polymères avec des pistes métalliques déposées à leur surface. Les objectifs de la thèse ont été d'optimiser les traitements de surface de polymères d'origine industrielle étudiés dans le contexte des MID pour obtenir des dépôts par métallisation electroless présentant une bonne adhérence. De plus, des procédés innovants de localisation de tels dépôts métalliques ont été développés. Durant ces travaux, la fonctionnalisation par plasma micro-ondes sous différentes atmosphères azotées et sous différentes conditions a été étudiée pour obtenir l'adsorption d'espèces palladiées (catalyseurs universels de la réaction de métallisation electroless). Des plans d'expériences ont été mis en oeuvre pour identifier un protocole type, développé sur PA12, pour obtenir des dépôts adhérents (Ni, Cu). Cette méthode a pu être globalement transposée avec succès sur d'autres polymères d'origine industrielle (ABS/PC, LCP). La seconde partie des travaux a consisté à développer des protocoles originaux basés sur des colloïdes de palladium directement synthétisés en surface d'un tampon en PDMS (lithographie douce) pour la réalisation de motifs métalliques par des procédés « top-down » et « bottomup ». Des analyses de surface AFM, SEM, TEM, XPS, ToF-SIMS et de mouillage ont permis de caractériser les différentes modifications de surface. Ces protocoles ont permis la réalisation de motifs métalliques MID adhérents jusqu'à 15 μm d'épaisseur et des motifs submicrométriques à haute résolution et haute densité avec des caractéristiques non encore obtenues à ce jour via cette technologieMolded Interconnected Devices (MID) consist in polymer based substrates with metal tracks at their surface. The aim of this thesis was to optimize surface treatments applied to industrial polymers intended for MID applications, in order to obtain electroless metal coatings exhibiting a high practical adhesion. Furthermore, innovative processes to localize these metal coatings were developed. In this work, surface functionalization based on various operating parameters of microwave plasma using various nitrogen-based atmospheres were studied to obtain palladium (universal catalyst for electroless metallization) adsorption. Designs of experiments were used to identify an optimal set of parameters for PA12 surface treatment to obtain adherent metal coatings (Ni, Cu). These conditions were overall successfully transferred to other industrial polymers (ABS/PC, LCP). The second part of this work consisted in the development of innovative processes based on the use of palladium colloids directly synthetized at the surface of PDMS stamps (soft lithography) to achieve localized metallization using bottom-up and top-down approaches. AFM, SEM, TEM, XPS, ToF-SIMS and wettability measurements allowed to characterise the various surface modifications. These processes made possible 15 μm thick MID metal patterns with satisfactory practical adhesion as well as high resolution and high density sub-micrometric patterns with unseen properties for this technology
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Cuynet, Stéphane. "Etude des conditions d’élaboration d’électrodes de pile à combustible PEMFC par procédés plasma". Thesis, Orléans, 2014. http://www.theses.fr/2014ORLE2027/document.
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Émanant d’une collaboration entre le laboratoire CNRS du GREMI et le CEA le Ripault, l’objectif de cette thèse est de réaliser une étude exhaustive sur les conditions d’élaboration des électrodes de pile à combustible PEMFC par procédés plasma, dont l’enjeu est d’améliorer l’activité électro-catalytique du catalyseur employé qu’est le platine (Pt). A même quantité, la répartition du platine sur son support se révèle être un critère déterminant sur les performances délivrées par les PEMFCs. De cette observation, plusieurs axes de recherche ont été proposés et chacun d’entre eux a permis d’obtenir de nouveaux résultats. Le régime de pulvérisation magnétron à haute puissance pulsée (HiPIMS) est étudié dans le cas de dépôt de matériaux nobles pures (Pt, Au, Pd) et alliés (Pt5Pd95 et Pt50Pd50) et a permis de révéler une vapeur métallique ionisée conséquente lors du dépôt (10 % à 90 % selon l’élément). Les résultats obtenus sur le régime HiPIMS ont permis la modification de la distribution d’une faible quantité fixée de Pt (20 μg.cm−2) déposée sur la profondeur des couches de diffusion des gaz (GDL), améliorant incidemment les performances des PEMFCs (+80 % à 0.65 V, la tension à puissance nominale). Ce résultat est complété par ceux obtenus sur l’élaboration de catalyseur alliés, notamment sur la disposition du matériel catalytique au niveau de la structure des agrégats (+93 % à 0.65 V pour Pt5Pd95 en dépôts successifs). Une autre étude a permis d’étudier la modification de répartition du Pt en contact avec la membrane électrolyte. La surface de membrane échangeuses de proton est alors initialement structurée. Ces structurations de surface des membranes montrent une amélioration globale des performances PEMFCs pour les architectures CCB (Catalyst Coated Backing) et CCM (Catalyst Coated Membrane) d’un facteur 1.3 jusqu’à 12, respectivementFrom a collaboration between the CNRS laboratory of the CEA and GREMI Ripault, the objective of this thesis is to conduct a complete study on the conditions for producing electrodes of PEM fuel cell by plasma processes in order to improve the electro-catalytic activity of the catalyst (Pt). The platinum atoms on its support appears to be a one of the most important factor determining the performance delivered by the PEMFCs. From this observation, several lines of research have been proposed and each of them has yielded new results. The High Power Impulse Magnetron Sputtering (HiPIMS) process is studied in case of depositions of noble materials (Pt, Au, Pd) and alloy (Pt5Pd95 and Pt50Pd50) and revealed an ionized metal vapor consequent upon deposition (10 % to 90 % depending of the element). The results obtained on the HIPIMS process have allowed a change in the distribution of a small fixed amount of Pt (20 μg.cm−2) deposited on the depth of the gas diffusion layer (GDL), incidentally improving the performance of PEMFCs (+80% at 0.65 V, the voltage at rated power). This result is complemented by those obtained on the development of allied catalysts, especially with the arrangement of the catalytic material on the aggregates structure (+93 % at 0.65 V for Pt5Pd95 in successive deposits). In order to modify the Pt atoms distribution on the membrane support, another study has been realized. The surface of the proton exchange membrane has been structurated before the Pt deposition. Such structuration have shown an increase of the overall performance of PEMFCs in the case of CCB (Catalyst Coated Backing) and CCM (Catalyst Coated Membrane) architecture with an improvement factor of 1.3 up to 12, respectively
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Rushforth, Andrew William. "The transport properties of two dimensional electron gases in spatially random magnetic fields". Thesis, University of Nottingham, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.342029.
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BONIFACIO, RAFAEL N. "Estudo e desenvolvimento de conjuntos membrana-eletrodos (MEA) para célula a combustível de eletrólito polimérico condutor de prótons (PEMFC) com eletrocatalisadores à base de paládio". reponame:Repositório Institucional do IPEN, 2013. http://repositorio.ipen.br:8080/xmlui/handle/123456789/10597.
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Made available in DSpace on 2014-10-09T12:42:20Z (GMT). No. of bitstreams: 0Made available in DSpace on 2014-10-09T13:59:42Z (GMT). No. of bitstreams: 0
Tese (Doutoramento)
IPEN/T
Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP
27
Kim, Yeong Ho. "Chromium-free consumable for welding stainless steel corrosion perspective /". Columbus, Ohio : Ohio State University, 2005. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1133285376.
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Coche, Liliane. "Préparation et étude électrochimique d'électrodes modifiées par des films de polymères rédox : application à la catalyse électrochimique rédox". Grenoble 1, 1987. http://www.theses.fr/1987GRE10046.
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Preparation d'electrodes de platine, palladium et rhodium modifiees par des films de polypyrrole et de poly (pyrrole-crologene). Application a la reduction electrochimique en milieu acetonitrile du dibromo-1,2 diphenyl-1,2 ethane
29
Ourari, Ali. "Étude de deux réactions d'électrocatalyse : hydrogénation électrocatalytique sur des films de polymères contenant des microparticules de métaux nobles et activation de l'oxygène par des complexes Mn(III) - bases de Schiff". Université Joseph Fourier (Grenoble ; 1971-2015), 1995. http://www.theses.fr/1995GRE10171.
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Ce travail est relatif a l'etude de deux reactions d'electrocatalyse. La premiere partie concerne la mise au point de cathodes moleculaires, realisees par l'inclusion de microparticules de metaux nobles dans des films de polypyrrole fonctionnalise et a leur application en hydrogenation electrocatalytique. L'etude de l'hydrogenation de deux substrats test, le limonene et la carvone, a montre qu'il est possible d'orienter la selectivite de ces electrodes modifiees selon la nature du metal incorpore (pt, pd ou rh). Le resultat le plus significatif est que l'incorporation dans le meme film de polymere de deux metaux d'activite catalytique differente (pt + pd ou rh + pd) conduit a des cathodes dont l'efficacite et la selectivite sont largement superieures a celle des cathodes basees sur un seul metal. La deuxieme partie de ce travail est consacree a l'etude de l'activation electrochimique de l'oxygene par des complexes mn (iii) - bases de schiff. Il apparait que le complexe mn (ii) - salen substitue en 5,5 par des atomes de chlore est le catalyseur le plus stable et le plus efficace pour la reaction test d'epoxydation du cyclooctene. D'autre part, la rigidification du complexe par l'utilisation d'un pont 1,2-cyclohexylidene ou 1,2-phenylene reliant les deux motifs salicylaldehyde du ligand, a la place du groupe ethylidene ligand salen, entraine une forte diminution de l'activite catalytique des complexes correspondants. Ce systeme electrocatalytique a egalement ete applique a l'oxydation de la tetraline et de la triphenylphosphine
30
Johansson, Anders. "Template-Based fabrication of Nanostructured Materials". Doctoral thesis, Uppsala : Acta Universitatis Upsaliensis, 2006. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-7364.
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Bonifacio, Rafael Nogueira. "Estudo e desenvolvimento de conjuntos membrana-eletrodos (MEA) para célula a combustível de eletrólito polimérico condutor de prótons (PEMFC) com eletrocatalisadores à base de paládio". Universidade de São Paulo, 2013. http://www.teses.usp.br/teses/disponiveis/85/85134/tde-09012014-144413/.
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Sistemas de PEMFC são capazes de gerar energia elétrica com alta eficiência e baixa ou nenhuma emissão de poluentes, porém questões de custo e durabilidade impedem sua ampla comercialização. Nesse trabalho foi desenvolvido um MEA com eletrocatalisadores à base de paládio. Foram sintetizados e caracterizados eletrocatalisadores Pd/C, Pt/C e Ligas PdPt/C com diferentes razões entre metais e carbono. Foi realizado um estudo da razão entre ionômero de Nafion e eletrocatalisador para formação de triplas fases reacionais de máximos desempenhos, criado um modelo matemático para transpor esse ajuste para eletrocatalisadores com diferentes razões entre metal e suporte, considerando os aspectos volumétricos da camada catalisadora, e então realizado um estudo da espessura da camada catalisadora. Para as caracterizações foram utilizadas as técnicas de Difração de Raios-X, Microscopias Eletrônicas de Transmissão e de Varredura, Energia Dispersiva de Raios-X, Picnometria a Gás, Porosimetria por Intrusão de Mercúrio, Adsorção de Gás, segundo as equações de BET e BJH, Análise Termo Gravimétrica e feitas as determinações de diâmetros de partículas, de áreas de superfície específica e de parâmetros de rede. Todos os eletrocatalisadores foram usados no preparo de MEAs que foram avaliados em célula unitária de 5 cm2 entre 25 e 100 °C a 1 atm; e a melhor composição foi avaliada também a 3 atm. No estudo dos metais para as reações, visando reduzir a platina aplicada aos eletrodos, sem perdas de desempenho, foram selecionados Pd/C para ânodos e PdPt/C 1:1 para cátodos. A estrutura de MEA desenvolvida utilizou 0,25 mgPt.cm-2 e resultou em densidades de potência de até 550 mW.cm-2 e potências de até 2,2 kWe por grama de platina. A estimativa realizada mostrou que houve uma redução de até 64,5 % nos custos em relação à estrutura de MEA previamente conhecida. Em função da temperatura e pressão de operação foram obtidos valores a partir de R$ 3.540,73 para o preparo de MEAs para cada quilowatt instalado. Com base em estudos recentes, concluiu-se que o custo do MEA desenvolvido é compatível às aplicações estacionárias de PEMFC.PEMFC systems are capable of generating electricity with high efficiency and low or no emissions, but durability and cost issues prevent its large commercialization. In this work MEA with palladium based catalysts were developed, Pd/C, Pt/C and alloys PdPt/C catalysts with different ratios between metals and carbon were synthesized and characterized. A study of the ratio between catalyst and Nafion Ionomer for formation of high performance triple-phase reaction was carried out, a mathematical model to implement this adjustment to catalysts with different relations between metal and support taking into account the volumetric aspects of the catalyst layer was developed and then a study of the catalyst layer thickness was performed. X-ray diffraction, Transmission and Scanning Electron Microscopy, X-ray Energy Dispersive, Gas Pycnometry, Mercury Intrusion Porosimetry, Gas adsorption according to the BET and BJH equations, and Thermo Gravimetric Analysis techniques were used for characterization and particle size, specific surface areas and lattice parameters determinations were also carried out. All catalysts were used on MEAs preparation and evaluated in 5 cm2 single cell from 25 to 100 °C at 1 atm and the best composition was also evaluated at 3 atm. In the study of metals for reactions, to reduce the platinum applied to the electrodes without performance losses, Pd/C and PdPt/C 1:1 were selected for anodes and cathodes, respectively. The developed MEA structure used 0,25 mgPt.cm-2, showing power densities up to 550 mW.cm-2 and power of 2.2 kWnet per gram of platinum. The estimated costs showed that there was a reduction of up to 64.5 %, compared to the MEA structures previously known. Depending on the temperature and operating pressure, values from US$ 1,475.30 to prepare MEAs for each installed kilowatt were obtained. Taking into account recent studies, it was concluded that the cost of the developed MEA is compatible with PEMFC stationary application.
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Nemra, Ghinwa. "Comportement electrochimique de nouveaux complexes a liaison pd-pd et pt-pd stabilises par des ligands bidentates ph : :(2)pch::(2)pph::(2)". Strasbourg 1, 1986. http://www.theses.fr/1986STR13055.
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L'etude des proprietes redox d'une vingtaine de complexes mono-, di-, tri- et tetranucleaires du palladium et du platine a ete effectuee par des methodes electrochimiques (electrode a disque tournant, voltamperometrie cyclique et coulometrie) associees a des methodes spectroscopiques (spectrophotometrie d'absorption electronique, rpe et rmn). Les differents mecanismes des reactions redox ont ete etablis en fonction de la nature des metaux et des ligands dans le complexe. On montre qu'on peut modifier de maniere controlee les potentiels d'oxydoreduction et la reversibilite des transferts de charge par un choix convenable de parametres: metaux, ligands (phosphine, co) et milieu d'etude. Les resultats obtenus contribuent a l'etude de la reactivite electrochimique de la liaison metal-metal dans les complexes des metaux de transition
33
yeh, hui chen y 葉慧君. "Preparation of Platinum —Palladium alloy Nanostructured Electrodes". Thesis, 2004. http://ndltd.ncl.edu.tw/handle/58776624795881723392.
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碩士南台科技大學
化學工程系
92
Pt — Pd alloy, Pt, and Pd nanoparticles were synthesized in reverse micellar solutions, employing H2PtCl6/Pd(NH3) 4Cl2 as the precursors, N2H5OH as the reductant, water as the dispersion phase, sodium di-2-ethylhexyl sulfosuccinate (AOT) as the surfactant, and isooctane as the continuous phase. The size of the resultant nanoparticles, which depends on the molar ratio of water to AOT, ω0, was about 10 nm at ω0 = 9 from TEM images. It was found that the composition of the Pt — Pd alloy nanoparticles had no effect on average particle size. The nanostuctured electrodes were prepared by electrophoretic deposition of the nanoparticles on Ti supports under a potential field of 1000 V/cm, followed by a heat treatment in air. In this study, we prepared nanosturctured Pt — Pd alloy electrodes, nanostructured Pt + Pd co-deposition electrodes, and nanostructued Pt electrodes; then compared their electrochemical activities towards methanol oxidation in 1.0 M NaOH aqueous solution. It could be confirmed that the nanoparticles were deposited on the Ti support from FE—SEM images. EDS analysis revealed that the composition on the surface of the nanostructured Pt — Pd alloy electrode was almost equal to that of the preparation solution of the Pt — Pd alloy nanoparticles, indicating that the Pt — Pd nanoparticles had a homogeneous alloy phase. The electrochemical activity of the nanostructured Pt — Pd alloy electrodes towards methanol oxidation in 1.0 M NaOH + 0.1 M CH3OH aqueous solution was investigated by cyclic voltammetry, CV. The results showed that the current density of the reaction decreased with increasing heat treatment temperature. Although decreasing heat treatment temperature increases the current density, lower temperature would weaken adhesion force between the nanoparticles and the Ti support. In this study, it was found that the optimum heat treatment temperature was 400℃. Furthermore, with increasing the Pd content of the electrode, the current density for methanol oxidation increased first, and then decreased after reaching a maximum at 80 mole % Pd. Also, the onset potential for methanol oxidation decreased with increasing Pd content; then increased after reaching a minimum value of 0.381 V at 80 % Pd. The potential of the nanosturctured Pt — Pd alloy electrodes was held at 0.825 V; then the dependence of the current density for methanol oxidation on reaction time was examined, an approach known as j — t method. It was found that the initial current density, j value at t = 0.05 sec, increased with increasing the Pd content of the electrode and decreased after reaching a maximum value of 68.7 mA/cm2 at 80 mole % Pd. These results were similar to those obtained by CV method. The electrochemical activity of the nanostructured Pt + Pd co-deposition electrodes towards methanol oxidation was investigated by both CV and j — t methods. The results showed that the Pd content of the electrode affected the activity of the electrode in the same way as that of the nanostuctured Pt — Pd alloy electrode. However, the maximum activity of the nanostructured Pt + Pd co-deposition electrode occurred at 40 mole % Pd. Compared with the other electrodes, the nanostructured Pt — Pd alloy electrode with 80 mole % Pd has the highest activity for methanol oxidation. The series of active electrodes are as follows: nanostructured Pt — Pd alloy electrode > nanostructured Pt + Pd co-deposition electrode > nanostructured Pt electrode > bulk Pt electrode. In the CV method, the ratios of the activity of the nanostructured Pt — Pd alloy electrode with 80 mole % Pd to that of the other electrodes were 1.6 to the nanostructured Pt + Pd co-deposition electrode with 40 mole % Pd, 3 to the nanostructured Pt electrode, and 13.7 to the bulk Pt electrode, based on the peak (P1) current density. Also, in the j — t method, the corresponding ratios were 1.65, 3.3, and 15, based on the initial current density. The electron-transfer limiting current density, je, for methanol oxidation was obtained by the rotating-disc electrode method. The rate constant of methanol oxidation at a given temperature was obtained by plotting je against methanol concentration. From the rate constants obtained at different temperatures, the activation energy for methanol oxidation catalyzed by electrodes was calculated. The rate constants obtained at 25℃ for the nanostructured Pt — Pd alloy electrode with 80 mole % Pd and for the bulk Pt electrode were 1.38×10 -6 s -1 and 1.41×10-8 s -1, respectively. Then the activitation energies calculated for the corresponding electrodes were 22.8 kJ/mole and 56.9 kJ/mole, respectively.
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Zahm, Lance Leon. "Nuclear investigations of the eletrolysis of D₂O using palladium cathodes and platinum anodes". Thesis, 1990. http://hdl.handle.net/1957/37958.
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Wang, Chueh-Han y 王覺漢. "Electrochemical Sensing Performance of Graphene/Palladium/Ionic liquid Nanocompositie Electrodes". Thesis, 2012. http://ndltd.ncl.edu.tw/handle/47056651713935006026.
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碩士國立中央大學
材料科學與工程研究所
100
In this study, we use graphen-based and multiwall carbon nanotubes-based(MWCNT) materials as electrochemical sensing electrode to detect ascorbic acid(AA), dopamine (DA) and uric acid (UA). In order to enhance sensitivity and selective, nano-sized Pd catalyst particles are uniformly dispersed on both the carbon supports using a supercritical fluid deposition techniquein in which the MWCNT/Pd electrode shows higher detection current than that of the Graphene/Pd electrode. Besides Pd NPs, IL also utilized for application, the detection sensitivity of the Graphene/IL electrode is significantly promoted and noticeably outperforms that of the MWCNT/IL. Six different ILs are investigated in this research, including 1-ethyl-3-methylimidazolium thiocyanate (EMI-SCN), 1-butyl-1-methylpyrrolidinium bis (trifluoromethyl) sulfonyl imide (BMP-NTf2), 1-butyl-1-methylpyrroli dinium dicyanamide (BMP-DCA), 1-butyl-3-methylimidazolium hexafluorophosphate (BMI-PF6 ), 1-ethyl-3-methylimidazolium bis(trifluoromethyl)sulfonyl imide (EMI-NTf2) and 1-ethyl-3-methylimidazolium dicyanamide (EMI-DCA). Both Pd NPs and IL could improve sensing performance, nevertheless, mixture of Graphene/Pd/IL electrode is not as good as graphene/IL electrode. The experimental result elucidated the cation dominate the sensing behavior as SCN- > DCA- > PF6- > NTF2-. In the case of glucose, graphene cannot detect glucose in spite of IL existence, while Pd NPs supports act as catalyst can enhance performance. Especially Graphene/Pd/IL combination could improve sensing performance, the sensing behavior that also effected by cation, there are NTF2- > PF6- > DCA- > SCN-. For simultaneous detection different analyte, the satisfactory selectivity and sensitivity can obtain by choosing suitable NPs or ILs that performs great potential in electrochemical sensing.
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Yang, Rong-Feng y 楊榮烽. "Electrochemical synthesis and characterization of palladium nanoparticles, polyaniline / palladium nanoparticles, and NDGA / palladium nanoparticles film modified electrodes and their electrocatalytic properties". Thesis, 2008. http://ndltd.ncl.edu.tw/handle/3d8ux6.
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碩士國立臺北科技大學
化學工程研究所
96
PartⅠ:Palladium nanoparticles(nano Pd) film modified glassy carbon electrode (GCE) was fabricated by using electro-deposition method from 0.5M sulfuric acid containing 10-3M potassium tetra chloro palladate (III). To examine the surface morphological analysis, the nano Pd film was electrochemically deposited on transparent semiconductor indium tin oxide (ITO) electrodes for scanning electron microscopy (SEM),atomic force microscopy (AFM) and x-ray diffraction studies (XRD).From the SEM and AFM analysis,it was observed that the deposited palladium nanoparticles were in the size range of 39-78 nm, respectively.Further the nano Pd film on GCE was characterized by using electrochemical impedance spectroscopy studies (EIS).Electrochemical quartz crystal microbalance (EQCM) technique has been employed to measure the mass of nano Pd film deposition on the gold electrode surface.In addition,the electrochemical behavior of nano Pd film was examined in different pH solutions.Palladium nanoparticles modified GCE could be used for the individual detection of catecholamine neurotransmitters epinephrine(EP),norepinephrine(NEP) and dopamine(DA) in pH 7 phosphate buffer solutions (PBS). The selective detection and determination of catecholamine neurotransmitters in the presence of ascorbic acid (AA), the main interference, were achieved.With good stability and reproducibility,the present nano Pd film modified GCE was applied for the detection of EP, NEP and DA from injection solutions in presence of AA (obtained from commercially available vitamin C tablets) and the satisfactory results were obtained. PartⅡ：Palladium nanoparticles were electrochemically deposited into an electro active polyaniline modified glassy carbon (GC) electrode to fabricate a novel bi-layer film GC electrode.Here,the cyclic voltammetry was performed to form the electro active polymer,poly aniline, palladium nanoparticles,respectively.Further the proposed film modified electrodes'' surface analysis has been done by using AFM microscopy.Here the palladium nanoparticles were electrochemically deposited onto the porous nature of the polyaniline layer.Next,this type of film modified electrodes electrocatalytic activity was evaluated by oxygen reduction reaction (ORR).LSV and hydrodynamic voltammograms were used to demonstrate the enhanced electrocatalytic activity of poly aniline (PA)/nano Pd film modified GCE. Furthermore, chronoamperometric experiments were carried out to investigate the kinetic parameters of oxygen reduction reaction on this type of proposed electrode,respectively. PartⅢ：This article discusses the results for the fabrication of nordihydroguaiaretic acid (NDGA)/nano Pd film modified glassy carbon electrode (GCE) for the detection of arsenic(III) in water.A thin NDGA film was electro chemically deposited onto a GCE.Next the palladium nanoparticles were electrochemically deposited onto the NDGA modified GCE by using cyclic voltammetry.The surface morphology of the NDGA / nano Pd film was examined by using SEM and AFM techniques,respectively.Further electrochemical behaviors of the NDGA/ nano Pd film were examined by EIS studies.The proposed film on GCE showed a high sensitivity in detecting arsenic (III) by using DPV. In addition,the NDGA/nano Pd film modified electrodes were examined in real sample analysis studies such like mineral water and tap water.Also,a satisfactory linear range of detection was found and which is almost equal to the arsenic guideline limit announced by the world health organization,respectively.
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Arenz, Matthias [Verfasser]. "Model electrodes for electrocatalysis : Ultrathin palladium films on Pt(111) / vorgelegt von Matthias Arenz". 2002. http://d-nb.info/966390350/34.
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Cheng, Yu-Shun y 鄭鈺舜. "Studies on Microwave-assisted Synthesis and Pulse Electrodeposition of Palladium Nanocatalysts on Amino-Functionalized Carbon Nanotube-based Electrodes". Thesis, 2010. http://ndltd.ncl.edu.tw/handle/32397162653610282667.
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碩士元智大學
化學工程與材料科學學系
98
The CNTs was directly grown on microscaled carbon paper by using catalytic chemical vapor deposition. Amino-functionalization of carbon nanotubes (CNTs) attached to carbon paper (CP) has been achieved using one synthetic protocol: (i) chemical oxidation, (ii) acyl chlorination, and (iii) amidation. The amidation reaction of the carboxylic groups in oxidized CNT/CP composites enables the formation of terminal amino groups on the CNT sidewalls. The functionalized CNTs were characterized by Raman spectroscopy, X-ray photoelectron spectroscopy, and N2 adsorption. The cyclic voltammetry curves of amino-modified CNT-based capacitor showed a continuum of double-layer and pseudocapacitive behavior. The presence of surface oxides and amides on CNTs imparts not only hydrophilic coverage for formation of double-layer (double-layer capacitance) but also active sites for redox reaction (pseudocapacitance). On the basis of result from charge/discharge cycling test, N-modified CNT/CP capacitor exhibits an enhanced capacitance, high-rate capability, and capacitance stability with high coulombic efficiency. The deposition of palladium nanoparticles, prepared by microwave-assisted synthesis (MS) and pulse electrodeposition (PE), on amino-modified CNT/CP composites has been investigated. Both MS and PE methods enabled the fast formation of nanosized Pd particles over CNT surface without any additional thermal reduction. Cyclic voltammetry and electrochemical impedance spectroscopy were adopted to examine electrochemical behavior of Pd catalysts. The Pd catalyst, prepared by MS method, offers not only high active coverage for adsorption/desorption of hydrogen but also stable durability toward acid electrolyte, comparing with that by PE method. The electrochemical surface area of the Pd catalyst was approximately 1.26 times than that of the Pt, also prepared by MS method. The equivalent series resistance for all catalyst electrodes was kept at 2.07−2.25 Ω after the potential cycling. On the basis of the result, the Pd catalyst offers a feasibility to replace Pt catalyst due to low cost, durability, and high catalytic activity.
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Chang, Jui-Lung y 張瑞龍. "Fabrication of the p-GaN Electrode by Using the Electroless Chemical Process of Nikel-Palladium-Gold". Thesis, 2013. http://ndltd.ncl.edu.tw/handle/p98g5y.
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碩士國立虎尾科技大學
光電與材料科技研究所
101
In this thesis, electroless chemical Nikel-Palladium-Gold(Ni/Pd/Au) process was developed on p-GaN electrode. It is selective deposition which has cost and time saving benefit. The ohmic contact properties of p-GaN e- lectrode were studied by different Ni and Pd thickness. Au was peeling off the electrode without Pd in the tri-layer structure. Characteristic resistance of p-GaN electrode was measure by transmission line model(TLM). Comparing nitrogen and argon atmospheric annealing, which showed the former has better performance than the latter. As annealing temperature increased to 450℃the resistance decreased, then increasing as temperature over 450℃. I-V, Electroluminescence(EL) and modulation bandwidth was observed by different treatment condition. Pd showed good to Au adhesion with Ni by eutectic formation. Meanwhile, forward voltage (Vf), leakage current (IR) and wavelength were improved by Pd introduce.
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Bair, Ju Shuh y 朱恕白. "The Study of Microstructures of Palladium Electrode after Deuterium Charging". Thesis, 1993. http://ndltd.ncl.edu.tw/handle/44631796681945842782.
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Pei, Hong-Yuan y 裴宏原. "The applications of electrodeposited palladium nanoparticles on carbon fiber paper electrode". Thesis, 2019. http://ndltd.ncl.edu.tw/handle/grrgbv.
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碩士國立交通大學
分子醫學與生物工程研究所
107
According to the previous studies, the modification of carbon fiber paper (CFP) electrode with different metal nanoparticles demonstrates great catalytic properties toward many bioactive molecules. In this study, in order to promote the catalytic abilities of CFP, the electrodeposition of palladium nanoparticles (Pd NPs) has adopted to improve the electrochemical characteristics on the surface of CFP. The Pd-based CFP electrodes are optimized to sense or react with specified molecules. The catalytic reaction of hydrogen peroxide is explored by cyclic voltammetry (CV) and the oxidative current is 33.26 μA. In addition, the oxidation reaction of ethanol in alkaline media is also demonstrated by CV. PdNP/CFP electrode exhibits a peak current and current density of 81.2 mA and 541.32 mA cm-2 (or 68.22 mA mg-1 Pd), respectively. Moreover, the morphologies and distribution of Pd NPs on CFP are the factors to affect the catalytic properties. Through the optimal modification on the surface of CFP, we expect it could be applied in the development of biosensor and fuel cell.
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He, Min-Ching y 何旻璟. "The Study of Electroless Palladium Plating on Low-Carbon Steel". Thesis, 2011. http://ndltd.ncl.edu.tw/handle/93666285296346672226.
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碩士逢甲大學
材料科學所
99
In this study, low carbon steel was coated with Pd-P film by electroless plating method. The alkaline solution containing sodium hypophosphite as reducing agent was used for plating. The amount of phosphorus deposited was varied with pH value (8.0, 9.0, 10.0, or 11.0) of electroless palladium plating solution. Microstructures and surface morphology of Pd-P films were identified by GID and FE-SEM. Corrosion resistance , microhardness and electrical conductivity of deposits were analyzed by potentiostat, Vickers microhardness tester, and four-point probe, respectively. In the process of electroless plating , the amount of palladium in coating was increased as the bath pH value increased. However, the phosphorus content was decreased as the bath pH value increased. As the amount of phosphorus increased in the film, it caused the poor crystallinity and higher electrical resistance. On the other hand, corrosion resistance and hardness of coatings were enhanced. By using Pd-P/low carbon steel as electrode for cyclic voltametry, the effectiveness of the Randles-Sevcik equation was examined. The efficiency was 78.2% for water electrolysis with the optimal combination of parameters, such as current density 5 A/dm2, and sodium chloride content 10 wt% in aqueous solution.
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Kuo, Li-Chen y 郭娌禎. "Preparation and Characterization of Palladium Nanoactivator for Electroless Nickel Deposition". Thesis, 2006. http://ndltd.ncl.edu.tw/handle/73700686410599094605.
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碩士國立臺灣科技大學
材料科技研究所
95
Active colloids responsible for charge transfer and electron transfer in electroless metal bath me investigated in this study. Herein, the electrochemical analysis for the catalytic effect of Pd nanoparticles on deposition kinetic and microstructure in the electroless nickel-phosphorous bath was studied. As supported by linear sweep voltammetry (LSV), the currents for oxidation peaks corresponding to Pd nanoparticles upon increasing amount are measured to be enhanced. The result shows that Pd nanoparticles have excellent catalytic power in electroless nickel-phosphorous depositions (ENpD) bath. In addition, the deposition rate, analyzed by mixed potential theory (MPT), was found to increas from 6.31×10-2 �慊/cm2.s to 9.11×10-2 �慊/cm2.s. However, based on the same quantity of nanocatalyst, the deposition rates, which are in-situely monitored by electrochemical quartz crystal microgravimetry (EQCM), are measured to be faster than theoretical value given by deduced from conclude MPT. The results that that the cathodic currents for depositing hydrogen and phosphorous in the mixed potential theory could not be neglected upon reaching the equilibrium potential. As for an additional information, supported by field emission scanning electron microscope (FE-SEM), the continuous growth of nickel crystal was found after the induction time measured by EQCM. The narrowest distribution of nanosize grain was obtained at 120 seconds. In addition, the deposited layer of P with higher content was found to exist in the deposited microstructure catalyzed by the Pd nanoparticles at high concentration. Furthermore, mesoporous and self-assembled Pd nanopsheres have been prepared in the organized micellar template, sodium n-dodecyl sulfate (SDS), the electrostatic regulation of which was adjusted by adding H+ ions. The diameter of self-assembled nanospheres can be controlled from ~41.5nm to ~56.2 nm by the concentration of palladium ions added. As supported by the analysis of quartz crystal microgravimetry and mixed potential theory, the mesoporous nanospheres can be successfully used as activators and have the excellent activity for electroless nickel-phosphorous depositions. A comparison of deposition rate with a system of Pd nanospheres, the Pd nanosphere with small size was found to exhibit maximum activity toward oxidation of NaH2PO2, reducing agent of ENpD.
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Guo, Ting-Wei y 郭庭維. "Application of palladium-carbon on counter electrode of dye-sensitized solar cell". Thesis, 2018. http://ndltd.ncl.edu.tw/handle/3yqkfm.
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碩士國立東華大學
材料科學與工程學系
106
The study used of screen printing plate production of titanium dioxide working electrode, and the scattering layer. The experimental working electrode and the scattering layer used small particles of Degussa P25 titania powder and large particles of Degussa P200 titania powder mixed with small particle Degussa P25 titanium dioxide powder, respectively. First of all, to find the best working electrode layer, and then the scattering layer, to try different titanium tetrachloride treatment time to improve the short-circuit current density, the photoelectric conversion efficiency has increased from 6.19 % to 8.33 %. Sequentially, different concentrations of palladium-carbon suspension were added to the platinum counter electrode to find out the optimal concentration to obtain a better counter electrode. The experimental results showed that added a lower concentration of palladium-carbon suspension has helped to increase the short-circuit current density. Short-circuit current has increased from 15.49 mA/cm2 to 16.86 mA/cm2, which has improved the photoelectric conversion efficiency from 8.33 % to 8.61 %.
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Yang, Ki-Long y 楊基隆. "Hollow Silver/Palladium Triangular Nanoplate:A Novel Activator for Electroless Nickel Deposition". Thesis, 2009. http://ndltd.ncl.edu.tw/handle/63884523943322804841.
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碩士國立高雄應用科技大學
化學工程與材料工程系
97
Hollow Ag/Pd triangular nanoplates with uniform shells are successfully prepared by the galvanic displacement reaction, in which added Pd2+ ions react with Ag triangular nanoplates as templates. The morphology of the synthesized Ag/Pd nanostructures is observed to be that of regular triangular nanoplates with a hollow structure. The mean thickness of the side shells on hollow bimetallic nanoplates is found to be ~16.5 nm. As supported by the analysis of electrochemical quartz crystal microgravimetry, the mean deposition rate catalyzed by the prepared Ag/Pd triangular nanoshells is measured to be ~1.33 g/cm2s. The triangular alloy nanomaterials can be successfully used as activators and exhibit excellent activity in electroless nickel deposition.
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Chou, Yen-I. y 周彥伊. "Study on Fabrication of Palladium Schottky Diode Hydrogen Sensors by Electroless Plating". Thesis, 2001. http://ndltd.ncl.edu.tw/handle/87352910422372839893.
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碩士國立成功大學
化學工程學系
89
ABSTRACT In this study, electroless plating was employed to deposit palladium film on doped epitaxial GaAs and InP films for fabrication of palladium Schottky diodes as hydrogen sensors. The effect of kind and doping concentration of substrates as well as the concentration and composition of plating bath on palladium morphology had been investigated. Furthermore, the I-V characteristics and hydrogen detection performance of Schottky diodes obtained by thermal evaporation were also compared. The experimental results revealed that the microstructure of Pd film, strongly affected by the kind and doping concentration of substrates as well as the concentration and composition of plating bath, played an important role on the Schottky I-V characteristics. However, the electroless plating technique is a low-temperature process, which could eliminate the effect of Fermi-level pinning. As a result, the diodes fabricated by electroless plating exhibited the higher barrier height and lower ideality factor than those fabricated by thermal evaporation. From the results, the Pd/GaAs diodes showed no response on hydrogen. It was resulted from the Pd-Ga-As intermediate layer characterized by AES analysis. But, Pd/InP diodes demonstrated high sensitivity on hydrogen. The saturation sensitivity reached to 207 % even at 15 ppm hydrogen in air. From the I-V curves, it was found that the barrier height decreased and ideality factor increased with increasing hydrogen concentration. Besides, the response speed increased with increasing temperature and hydrogen concentration. In order to interpret the relationship of response voltage versus time, the hydrogen detection mechanism and kinetic model were proposed. The experimental results showed in consistent with that obtained from the theoretical prediction. Furthermore, the activation energy for the hydrogen adsorption was estimated to be about 47 kJmole-1 at temperature of 295－395 K. 授權書 口試合格證明 中文摘要 英文摘要 誌謝 總目錄 I 表目錄 IV 圖目錄 VI 符號說明 X 第一章 緒 論 1 1-1 感測器之簡介 1 1-1-1感測器之源由與定義 1 1-1-2感測器之分類 2 1-1-3感測器之發展 4 1-2 氣體感測器之簡介 4 1-2-1氣體感測器之需求 4 1-2-2氣體感測器之分類與原理 5 1-2-3氣體感測器之發展趨勢 8 1-3 氫氣感測器之簡介 8 1-3-1氫氣感測器之種類 8 1-3-2半導體式氫氣感測器 9 1-3-3蕭特基二極體式氫氣感測器之發展 10 1-4 研究動機與目的 12 第二章 理 論 22 2-1無電鍍鈀 22 2-2蕭特基二極體之氫氣感測原理 24 2-2-1鈀蕭特基二極體元件特性 24 2-2-2氫氣感測理論 27 2-3氫氣感測模式之探討 28 2-3-1二極體電性特性與氫氣濃度之關係 28 2-3-2氫氣吸附之動力模式 31 第三章 實驗部分 39 3-1藥品與材料 39 3-2儀器及分析方法 40 3-2-1分析儀器 40 3-2-2設備及裝置 41 3-3實驗方法及步驟 41 3-3-1元件製作 41 3-3-2氫氣檢測實驗 44 第四章 結果與討論 49 4-1鈀膜特性分析 49 4-1-1鍍膜方法之影響 49 4-1-2基材之影響 50 4-1-3鍍浴濃度之影響 51 4-2二極體元件之電性分析 52 4-2-1鍍膜方法之影響 52 4-2-2鍍浴濃度之影響 54 4-2-3鍍浴組成之影響 55 4-3氫氣感測性能 56 4-3-1 Pd/GaAs之氫氣感測性能 56 4-3-2 Pd/InP之氫氣感測性能 58 4-4氫氣感測機構與模式分析 60 4-4-1蕭特基二極體之氫氣感測機構 60 4-4-2動力模式探討 65 第五章 結論 121 參考文獻 125 自述
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Li, Poyi y 李柏毅. "Interfacial reactions of lead-free solders with electroless palladium on the nickel substrate". Thesis, 2012. http://ndltd.ncl.edu.tw/handle/22944125394377238894.
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碩士國立中正大學
化學工程研究所
100
With the miniaturization of electronic products, the plating finishing techniques can not conform to the requirement. Therefore, electroless plating finishing techniques play an important in electronic industry. Among finishing techniques, ENEPIG has many advantages and begin using widely. In this study, we used the Ni plate as substrate and then electroless Pd and immersion Au on the substrate. Therefore, the influence of Cu substrate can be neglected. Besides, Pd foils were also studied in this research. The solid-solid reaction couple and liquid-solid reaction couple were made by electroless plating and electroplating. The results indicated that PdSn4 had much Ni amount than Pd because of Ni diffusion from Ni substrate, and the PdSn4 became more thicker. However, Sn/Au/Pd(1µm)/Ni reaction couple would observe PdSn4 had much Pd content than Ni after 10 s of reflow time. The reflow time and the thickness of Pd layer had a significant effect on microstructure. Interface of Sn/Au/Pd(1µm)/Ni could produce PdSn4 layer in short period of time. However, PdSn4 layer could not maintain with increasing reflow times. On the other hand, the intermetallic growth kinetics of solid/solid reaction was studied. The results showed electroless Pd on Ni could influence thickness of Ni3Sn4. Our research also studied in electro-Ni/Au/Sn/Au/Pd/Ni and electro- Cu/Au/Sn/Au/Pd/Ni. A needle shape PdSn4 compound grew on electroplate Ni side in electro-Ni/Au/Sn/Au/Pd/Ni reaction couple. This indicated that needle shape PdSn4 compound will be affected by the opposite Sn/Au/Pd/Ni interfacial reaction. PdSn4 had a large amount of Au content on Ni plate side in electro-Cu/Au/Sn/Au/Pd/Ni reaction couple. The phenomenon might be related to (Cu,Ni)6Sn5. (Cu,Ni)6Sn5 acted as barrier layer to prevent Ni diffusion into PdSn4. In addition, we also studied in Sn-3Ag-0.5Cu/Au/Pd/Ni. The results indicated that Ni content of PdSn4 decreased and Cu6Sn5 compound grew on PdSn4/Ni interface. Besides, Ni3Sn4 will appear on the interface with increasing time. The results show that (Cu,Ni)6Sn5 acted as barrier layer to prevent Ni diffusion into PdSn4 and Ni3Sn4 will apear on the interface with increasing time. The Zn concentration effect was studied in Sn-Zn/Pd solid/solid reaction and Sn-Zn/Pd liquid/solid reaction. In solid/solid reaction, adding small amount of Zn could inhibit formation of PdSn4 on interface. In liquid/solid reaction, Pd2Zn9 was formed as the Zn is about 1.5wt%. However, PdSn4 was found when below 2wt%Zn. Sn-Zn solder reacted with Ag substrate or Ni substrate that was also discussed in this study. The Zn contentment difference would alter the species of reaction phase in Sn-Zn/Ag couple and Sn-Zn/Ag/Cu couple. Ag-Zn phase was formed as the Zn concentration is higher. However, Ag-Sn phase was formed as the Zn concentration is lower. IMC was changed between Ag3Sn and Cu with reaction increasing time. IMC was changed from Ag5Zn8 to Cu5Zn8, and then transfered into CuZn. Finally, IMC will be transfered into CuZn and Cu6Sn5 mixed-layer phase. Ni5Zn21 has two different contrasts in BEI image. Therefore, We etched interface by FIB that can observe four different microstructure in liquid/solid couple. The results showed that interface had two different microstructure in solid/solid couple. Besides, the microstructure will changed with reaction time increase in liquid/solid couple.
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Chen, Po-You y 陳帛佑. "The Application of Electroless Pure Palladium Deposition for Surface Finishing on Print Circuit Boards". Thesis, 2009. http://ndltd.ncl.edu.tw/handle/60327369628005553814.
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碩士國立清華大學
化學工程學系
97
我們的研究主要是在於開發一項替代性的表面處理製程，以改善印刷電路板工業上傳統金薄膜之表面處理製程的缺失。這項替代製程為：在銅基板上直接沉積一層無電鍍純鈀，其可以達到降低製程成本以及複雜度的目的。 為了檢視這項製程的效果，首先我們必須發展出一個可用的無電鍍純鈀鍍液。此鍍液的組成為：以氯化鈀作為鈀沉積層的來源，以乙二胺或檸檬酸鈉作為錯合劑，並且以甲酸鈉作為還原劑。 由紫外－可見光譜的結果顯示，乙二胺本身的pH值對於他的錯合能力有很大的影響。如果我們把乙二胺調至酸性條件下，其質子化的胺基會使他對鈀離子的錯合能力降低。因此我們可以鍍出以置換反應為主的鈀鍍層。但如果我們把pH值保持在乙二胺原本的強鹼性條件下，則會有乙二胺－鈀離子的強錯合物產生。因此我們可以得到以自催化還原反應為主的鈀鍍層。 以檸檬酸鈉作為錯合劑的鍍液系統相較於乙二胺系統有較好的穩定性，而鈀離子與檸檬酸鈉間的最佳比例為1:50。如果我們用氨水把鍍液的pH值調到6∼8，則能到較強的檸檬酸鈉－鈀離子錯合物。但若用氫氧化鈉來調整pH則無額外的錯合效果。這是因為氨水分子中所含的胺基也有錯合能力的緣故。而由實驗顯示，此系統之純還原鍍鈀液在pH=6以及65℃.時會有最好的浸鍍活性。 由XRD的結果顯示，檸檬酸鈉系統的無電鍍鈀層為一多晶薄膜。但由於純置換的活化鈀層厚度太薄，因此鈀的訊號很弱而銅的訊號明顯。此外，打線能力測試結果顯示其拉力幾乎都大於6 cN，可通過工業上的評量標準。
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Lin, Wei-Ti y 林緯廸. "Application of Electroless Copper Plating on Photo-imageable Dielectric Material by Reactive Palladium Nanoparticles". Thesis, 2017. http://ndltd.ncl.edu.tw/handle/ev8xr9.
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碩士國立交通大學
理學院應用科技學程
106
Electroless-deposition Copper (E’less Cu) is one of most commend technique in electronic package industry. In this work, two step surface modification technique is applied to set up an attachable surface by using RCA-SC1 (standard clean process of semiconductor industry) or radio frequency (RF) power plasma and the 3- 2-(2-aminoethylamino) ethylamino propyl trimethoxysilane (ETAS) for PVA-Pd attach which as the catalyst of E’less deposition. Applying the catalyst agent developed in previous study and synthesized in the laboratory. Using polyvinyl alcohol (PVA) as protective agent of the palladium nanoparticle with well-define size of 2-5nm. [1] The PID surface modification and the adhesion between PID and e’less Cu is evaluated by water contact angle, X-ray photoelectron spectroscopy (XPS), scanning electron microscope (SEM), atomic force microscope (AFM), X-ray fluorescence analysis (XRF) and cross cut test. The results showed that using PVA-Pd as catalyst of E’less Cu on PID had better adhesion than commercial Sn/Pd and applying plasma is more suitable method than RCA-SC1 for organic polymer as the surface hydrophilicity modification method. Based on SEM and AFM analysis, one of the factor to enhance the adhesion is that micro-morphology and roughness occurred after plasma process. The XPS analysis showed many functional groups generated after treatment it might be another factor to enhance adhesion performance of E’less Cu on PID. In the practical application point of view, this study demonstrate “wet process” alternative for PID metallization and try to resolve the mechanism of surface modification.
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Li, Meng-Han y 李孟翰. "Electroless Deposition of Palladium-based Alloy Membrane on an Alumina Support for Hydrogen Separation". Thesis, 2012. http://ndltd.ncl.edu.tw/handle/58281581332870732235.
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碩士國立交通大學
材料科學與工程學系
100
In this work, we attempt to fabricate a Pd-based alloy membrane on an alumina support via a sequential electroless deposition technique. The membrane enables the separation of hydrogen from a mixture of hydrogen and carbon dioxide at elevated temperature. We use commercial ceramic paste as a sealing material in which the debindering and sintering temperatures are identified as 600 and 1150 degree Celsius, respectively. From GC results, after proper sealing we attain desirable air tightness at 600 degree Celsius. The electroless deposition is conducted on a flat alumina disk initially in order to determine suitable processing parameters for targeted alloy composition. Materials characterization such as phase, composition, and morphology are carried out. The PdAg and PdAgCu membranes show homogenous single phase, and the surface maintains nicely after annealing at 600 degree Celsius. However, the PdAgCuNi membrane behaves differently because of phase separation between Cu and Ni. The roughness is found to increase in PdAgCu and PdAgCuNi as the deposition progresses, a fact that is attributed to the homogenous nucleation of Cu during electroless plating. The expected ratio for Pd-based alloy membrane can be controlled and estimated after careful weight determination. In addition, we successfully prepare PdAgCuNi alloy membrane on a porous alumina tube after proper sealing and the hydrogen permeation test will be performed shortly.