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Journal articles on the topic 'Potassium oxides'

Author: Grafiati

Published: 4 June 2021

Last updated: 1 February 2022

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1

Novosyolov, A., I. Olianina, I. Novoselova, et al. "RESEARCH OF THE POSSIBILITY OF REDUCING THE CIRCULATION OF SULFUR OXIDE IN THE PRODUCTION OF WHITE CEMENT." Bulletin of Belgorod State Technological University named after. V. G. Shukhov 6, no. 7 (2021): 89–98. http://dx.doi.org/10.34031/2071-7318-2021-6-7-89-98.

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The article discusses the possibility of reducing the circulation of sulfur oxide in the production of white cement by introducing alkaline potassium oxides K2O and sodium Na2O. A decrease in the circulation of sulfur oxide SO3 is achieved by increasing its yield in the clinker by transferring SO3 from a more sublimated compound of calcium sulfate CaSO4 to less sublimated potassium sulfates K2SO4 and sodium Na2SO4. Potassium and sodium oxides are introduced in the composition of carbonates and feldspar. The amount of introduced alkali oxides is controlled by the molar ratio A/S between sulfur oxide SO3 and alkaline oxides K2O and Na2O. It is shown that with the same molar ratio between sulfur oxide and alkaline oxides, the amount of SO3 removed with clinker depends on the ratio between potassium and sodium oxides. The higher the sodium oxide content, the more sulfur oxide comes out with the clinker and less remains to circulate in the kiln. The sublimation of sulfur oxide decreases from 70.5% - without the introduction of alkaline oxides, to 38,5 % at the maximum A/S ratio with the addition of potassium and sodium oxides in a ratio of 80:20 %. When potassium and sodium oxides are added in a ratio of 20:80%, the sublimation of sulfur oxide is reduced to  7,7 % at the same A/S ratio.

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2

JIANG, ZHI, HAIRONG ZHANG, ZHONGPENG WANG, MINGXIA CHEN, and WENFENG SHANGGUAN. "SIMULTANEOUSLY CATALYTIC REMOVAL OF NOx AND SOOT ON RARE EARTH ELEMENT OXIDE LOADED WITH POTASSIUM AND TRANSITION NANOSIZED METAL OXIDES." Nano 03, no. 04 (2008): 239–44. http://dx.doi.org/10.1142/s1793292008001088.

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The simultaneous catalytic removal of NO x and soot over the rare earth element (REE) oxide-based mixture oxides loaded with potassium and transition nanosized metal oxide (designated as M/K/REE oxide) was investigated by using temperature-programmed reaction (TPR). The influence of the type of REE oxides together with the type and amount of transitional metal oxides on the catalytic removal activity was discussed. K / Nd 2 O 3 was found to be the most active oxide among the REE oxides to simultaneous remove the NO x and soot under lean conditions. Chromium oxide was more active than the other transition metal oxides on enhancing the activity of soot oxidation of Nd 2 O 3 loaded with potassium. The optimum loading level of chromium was about 10 wt%, with ignition temperature at about 237°C and the conversion ratio NO → N 2 about 24.1%. The Mn -loading on K / Nd 2 O 3 resulted in the biggest conversion efficiency of NO to N 2 at about 30.2%. The increasing catalytic reaction of NO x–soot activities is attributed to the formation of complex crystalline phase in the catalyst together with the improving contacting between catalysts and soot.

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3

Lendzion-Bieluń, Zofia, Rafał Pelka, and Łukasz Czekajło. "Characterization of FeCo based catalyst for ammonia decomposition. The effect of potassium oxide." Polish Journal of Chemical Technology 16, no. 4 (2014): 111–16. http://dx.doi.org/10.2478/pjct-2014-0080.

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Abstract FeCo fused catalyst was obtained by fusing iron and cobalt oxides with an addition of calcium, aluminium, and potassium oxides (CaO, Al2O3, K2O). An additional amount of potassium oxide was inserted by wet impregnation. Chemical composition of the prepared catalysts was determined with an aid of the XRF method. On the basis of XRD analysis it was found that cobalt was built into the structure of magnetite and solid solution of CoFe2O4 was formed. An increase in potassium content develops surface area of the reduced form of the catalyst, number of adsorption sites for hydrogen, and the ammonia decomposition rate. The nitriding process of the catalyst slows down the ammonia decomposition.

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4

Black, DSC, and RJ Strauch. "Nitrones and Oxaziridines. XXXVII. Some Oxidation Reactions of 1-Pyrroline 1-Oxides." Australian Journal of Chemistry 41, no. 2 (1988): 183. http://dx.doi.org/10.1071/ch9880183.

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The 2,4-diaryl-1-pyrroline 1-oxides (4) can be converted into the related 2H-pyrrole 1-oxides (5) by treatment with N-bromosuccinimide and anhydrous potassium carbonate. Similar treatment of the 1-pyrroline 1-oxide (6) yielded the succinimido-substituted pyrroline (7). Selenium dioxide oxidation of the tetramethyl nitrone (8) under various conditions gave mixtures containing the compounds (10)-(12). Neither process provides a general conversion of 1-pyrroline 1-oxides into 2H-pyrrole 1-oxides.

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5

Makarov, V. A., and T. K. Savosteenko. "Determination of the mass fraction of potassium and sodium oxides in the dust of electric furnace filters by atomic emission spectrometry with inductively coupled plasma." Litiyo i Metallurgiya (FOUNDRY PRODUCTION AND METALLURGY), no. 3 (October 20, 2020): 62–66. http://dx.doi.org/10.21122/1683-6065-2020-3-62-66.

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A method of measuring the mass fraction of potassium and sodium oxides in the dust filters of electric arc furnaces by atomic emission spectrometry with the inductively coupled plasma (AES-ICP) was developed. Possibilities of atomic emission spectrometers of iCAP series for determination of potassium and sodium in dust of filters of electric arc furnaces are investigated.A method for converting potassium and sodium oxides into solution is proposed. Calibration of the spectrometer was carried out on aqueous solutions with a known concentration of potassium and sodium. For the preparation of calibration solutions, chemically pure potassium and sodium salts were used. Analytical lines of potassium and sodium free from spectral overlays are selected.A good correlation of calibration graphs is obtained. The developed technique is used to determine the mass fraction of potassium and sodium oxides in the dust filters of electric furnaces. Validation of the methodology was carried out. The repeatability of the results was compared with the repeatability of the standardized methodology. iCAP series spectrometers can be used to determine the mass of potassium and sodium oxides in gas cleaning dust.s cleaning dust.

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6

Šilhánková, Alexandra, Jana Hulvová, Petr Trška, and Miloslav Ferles. "Condensation reactions of 2,4- and 2,6-dimethylpyridines and their 1-oxides." Collection of Czechoslovak Chemical Communications 54, no. 6 (1989): 1687–704. http://dx.doi.org/10.1135/cccc19891687.

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Using the reactions of 2,4- and 2,6-dimethylpyridine-1-oxides with aromatic and heteroaromatic aldehydes under catalysis with potassium tert-butoxide (E)-aryl- and (E)-heteroarylethenylpyridine-1-oxides IIIa-IIIe, IVa-IVc, Va, Vb respectively, were prepared. 1-Oxides IIIg, IVd, IVe and Vc were obtained from the appropriate pyridine bases by oxidation with peracetic acid. Condensation of 2,4- and 2,6-dimethylpyridines with 3-pyridinecarbaldehyde gives a mixture of bases VIa and VIc, and VIb and VId, respectively. On Claisen condensation of 2,6- or 2,4-dimethylpyridine-1-oxide with diethyl oxalate in the presence of sodium hydride and potassium tert-butoxide lactone XIIa and XIIb is formed in addition to α-keto ester XIa and XIb, respectively. From esters XIa and XIb amides XId and XIe were prepared.

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7

Ando, Kazushi, Shinji Tamura, and Nobuhito Imanaka. "Potassium ion conductivity of KNO2 mixed oxides." Journal of Alloys and Compounds 408-412 (February 2006): 657–60. http://dx.doi.org/10.1016/j.jallcom.2004.12.067.

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8

Kalinina, M. I., O. A. Rakitin, L. F. Chertanova, L. I. Khmel'nitskii, and I. K. Moiseev. "Reaction of ?-hydroxyiminoacetonitrile oxides with potassium thiocyanate." Bulletin of the Academy of Sciences of the USSR Division of Chemical Science 40, no. 4 (1991): 784–88. http://dx.doi.org/10.1007/bf00958574.

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9

Ding, Keqiang. "Hydrothermal Synthesis of Leaf-Shaped Ferric Oxide Particles." E-Journal of Chemistry 6, s1 (2009): S280—S286. http://dx.doi.org/10.1155/2009/389765.

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For the first time, leaf-shaped ferric oxide particles were prepared from an aqueous solution of potassium ferricyanide [K3Fe(CN)6] by hydrothermal process. Images obtained from SEM (scanning electron microscope) revealed that leaf-shaped ferric oxides (around 1.5 μm in length) were clearly exhibited when the hydrothermal tempreature was 150°C, while as the temperature was increased to 200°C leaf-shaped ferric oxide particles with larger size were observed. XRD (X-ray diffraction) patterns testified that the obtained ferric oxides were α-Fe2O3with well-structured crystal faces. Interestingly, histograms describing the distribution of samples indicated that the distribution of obtained ferric oxide particles did not accord with gaussian distribution

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10

Sinha, M. M., and Anupamdeep Sharma. "Phonon spectra of superionic sodium and potassium oxides." Solid State Ionics 225 (October 2012): 211–13. http://dx.doi.org/10.1016/j.ssi.2012.04.005.

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11

Othman, M. R., Che Martunus, and W. J. N. Fernando. "Synthetic Hydrotalcite Prepared from Modified Combustion Method Using Glucose as Fuel." Advanced Materials Research 173 (December 2010): 146–49. http://dx.doi.org/10.4028/www.scientific.net/amr.173.146.

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Hydrotalcite (HT) like compounds were successfully synthesized from combustion method using aluminum and magnesium nitrates, and potassium carbonate as solid precursors. Glucose was used as solid fuel to facilitate the reaction into mixed oxide and later HT structure at different combustion temperature. The combusted product initially formed disordered mixed oxides, but later returned to its original, more ordered HT state after being in contact with carbonate solution as analyzed from XRD. SEM analysis showed that the sample's microstructure was more orderly packed, less granular and more refined than its mixed oxide counterpart. The EDX analysis showed that the elemental potassium was the strongest energy binding in the hydrotalcite network followed by Al, Mg, O and C.

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12

Wu, Lei, Kai Luo, Ling Zhang, Kai Wei та Wen-Chao Yang. "Latent Radical Cleavage of α-Allenylic C–O Bonds: Potassium Persulfate Mediated Thiolation of Allenylphosphine Oxides". Synthesis 50, № 15 (2018): 2990–98. http://dx.doi.org/10.1055/s-0037-1609835.

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A novel potassium persulfate (K2S2O8) mediated thiolation of allenylphosphine oxides with diaryl sulfides is disclosed. Mechanistic studies indicate that K2S2O8 homolyzes the diaryl sulfide to produce a thiyl radical (PhS•), which is followed by C–O bond cleavage of the allenylphosphine oxide under metal-free conditions, affording novel S,P-bifunctionalized butadienes in moderate to excellent yields.

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13

Hirano, Takenori. "Dehydrogenation of ethylbenzene over potassium-promoted iron oxide containing cerium and molybdenum oxides." Applied Catalysis 28 (December 1986): 119–32. http://dx.doi.org/10.1016/s0166-9834(00)82497-5.

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14

Tian, Zhaohui, Lijun Song, and Xinmin Li. "Effect of Oxidizing Decontamination Process on Corrosion Property of 304L Stainless Steel." International Journal of Corrosion 2019 (August 1, 2019): 1–6. http://dx.doi.org/10.1155/2019/1206098.

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Corrosion behaviors of 304L stainless steel (SS) and 304L SS with oxides film (preoxidation 304L SS) in 1 g/L potassium permanganate solution of various pH values were investigated by using mass loss, electrochemical measurement and scanning electron microscope (SEM) observation. The results showed that mass loss of 304L SS increases with the increase of sodium hydroxide or nitric acid concentration in 1 g/L potassium permanganate solution. The polarization curves of 304L SS in potassium permanganate solution show that passive zones are destroyed more easily in acid potassium permanganate solution than alkaline potassium permanganate solution. The corrosion ability of acid potassium permanganate (NP) decontamination solution used for 304L SS is more aggressive than alkaline potassium permanganate (AP) solution. The oxide film on the surface of preoxidation 304L SS can be removed completely in two oxidation reduction decontamination cycles, oxidizing solution of which comprised 0.4g/L sodium hydroxide and 1g/L potassium permanganate. The 304L SS and preoxidation 304L SS performed alkaline oxidation reduction decontamination of 3 cycles were reoxidation. The micromorphology of reoxidation specimens was similar to preoxidation 304L SS. Therefore the chemical decontamination of alkaline oxidizing and acid reducing steps had no negative effect on corrosion of 304L SS and reoxidation of 304L SS carried out decontamination.

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15

Maślankiewicz, Andrzej, and Maria J. Maslankiewicz. "Reactions of Some Dithiinodiquinoline 7-Oxides with Potassium Phenoxide." HETEROCYCLES 71, no. 1 (2007): 175. http://dx.doi.org/10.3987/com-06-10922.

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16

El-Shobaky, G. A., K. A. El-Barawy, and A. A. Ibrahim. "Thermal solid-solid interaction between potassium and manganese oxides." Thermochimica Acta 102 (June 1986): 21–27. http://dx.doi.org/10.1016/0040-6031(86)85309-6.

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17

Saber, John M., John L. Falconer, and Lee F. Brown. "Interaction of potassium carbonate with surface oxides of carbon." Fuel 65, no. 10 (1986): 1356–59. http://dx.doi.org/10.1016/0016-2361(86)90103-1.

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18

Zhu, Qing, Zeyu Jiang, Mudi Ma та ін. "Revealing the unexpected promotion effect of diverse potassium precursors on α-MnO2 for the catalytic destruction of toluene". Catalysis Science & Technology 10, № 7 (2020): 2100–2110. http://dx.doi.org/10.1039/c9cy02347j.

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19

DeLaHunt, John S., and Theodore G. Lindeman. "Review of the safety of potassium and potassium oxides, including deactivation by introduction into water." Journal of Chemical Health and Safety 14, no. 2 (2007): 21–32. http://dx.doi.org/10.1016/j.jchas.2006.09.010.

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20

Jirátová, Květa, Kateřina Pacultová, Kateřina Karásková, Jana Balabánová, Martin Koštejn, and Lucie Obalová. "Direct Decomposition of NO over Co-Mn-Al Mixed Oxides: Effect of Ce and/or K Promoters." Catalysts 10, no. 7 (2020): 808. http://dx.doi.org/10.3390/catal10070808.

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Co-Mn-Al mixed oxides promoted by potassium are known as active catalysts for the direct decomposition of nitric oxide (NO). In this study, the answer to the following question has been considered: does the presence of cerium in K-promoted Co-Mn-Al catalysts substantially affect the physical-chemical properties, activity, and stability in direct NO decomposition? The Co-Mn-Al, Co-Mn-Al-Ce, and Co-Mn-Al-Ce-K mixed oxide catalysts were prepared by the precipitation of corresponding metal nitrates with a solution of Na2CO3/NaOH, followed by the washing of the precipitate and calcination. Two other catalysts were prepared by impregnation of the Ce-containing catalysts with Co and Co+K nitrates. After calcination, the solids were characterized by chemical analysis, XRD, N2 physisorption, FTIR, temperature-programmed reduction, CO2 and O2 desorption (H2-TPR, CO2-TPD, O2-TPD), and X-ray photoelectron spectrometry (XPS). Cerium and especially potassium occurring in the catalysts affected the basicity, reducibility, and surface concentration of active components. Adding cerium itself did not contribute to the increase in catalytic activity, whereas the addition of cerium and potassium did. Catalytic activity in direct NO decomposition depended on combinations of both reducibility and the amount of stronger basic sites determined in the catalysts. Therefore, the increase in cobalt concentration itself in the Co-Mn-Al mixed oxide catalyst does not determine the achievement of high catalytic activity in direct NO decomposition.

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21

Hirano, Takenori. "Dehydrogenation of Ethylbenzene on Potassium-Promoted Iron Oxide Catalysts Containing Various Transition Metal Oxides." Bulletin of the Chemical Society of Japan 59, no. 5 (1986): 1653–55. http://dx.doi.org/10.1246/bcsj.59.1653.

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22

NAKAGAWA, Hiroshi, and Yoichi ONO. "Effects of potassium chloride on the reduction of iron oxides." Transactions of the Iron and Steel Institute of Japan 25, no. 10 (1985): 1021–24. http://dx.doi.org/10.2355/isijinternational1966.25.1021.

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23

Ye-Xin, ZHANG, SU Qing-Yun, WANG Zhong-Peng, GAO Xi-Yan, and ZHANG Zhao-Liang. "Surface Modification of Mg-Al Hydrotalcite Mixed Oxides with Potassium." Acta Physico-Chimica Sinica 26, no. 04 (2010): 921–26. http://dx.doi.org/10.3866/pku.whxb20100446.

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24

Tang, Horng-Yi, Hsiao-Yun Lin, Ming-Jye Wang, et al. "Crystallization and Anisotropic Properties of Water-Stabilized Potassium Cobalt Oxides." Chemistry of Materials 17, no. 8 (2005): 2162–64. http://dx.doi.org/10.1021/cm047707v.

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25

KALININA, M. I., O. A. RAKITIN, L. F. CHERTANOVA, L. I. KHMEL'NITSKII та I. K. MOISEEV. "ChemInform Abstract: Reaction of α-Oximinoacetonitrile Oxides with Potassium Rhodanide." ChemInform 23, № 44 (2010): no. http://dx.doi.org/10.1002/chin.199244078.

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26

Birkner, Nancy, and Alexandra Navrotsky. "Thermodynamics of manganese oxides: Sodium, potassium, and calcium birnessite and cryptomelane." Proceedings of the National Academy of Sciences 114, no. 7 (2017): E1046—E1053. http://dx.doi.org/10.1073/pnas.1620427114.

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Manganese oxides with layer and tunnel structures occur widely in nature and inspire technological applications. Having variable compositions, these structures often are found as small particles (nanophases). This study explores, using experimental thermochemistry, the role of composition, oxidation state, structure, and surface energy in the their thermodynamic stability. The measured surface energies of cryptomelane, sodium birnessite, potassium birnessite and calcium birnessite are all significantly lower than those of binary manganese oxides (Mn3O4, Mn2O3, and MnO2), consistent with added stabilization of the layer and tunnel structures at the nanoscale. Surface energies generally decrease with decreasing average manganese oxidation state. A stabilizing enthalpy contribution arises from increasing counter-cation content. The formation of cryptomelane from birnessite in contact with aqueous solution is favored by the removal of ions from the layered phase. At large surface area, surface-energy differences make cryptomelane formation thermodynamically less favorable than birnessite formation. In contrast, at small to moderate surface areas, bulk thermodynamics and the energetics of the aqueous phase drive cryptomelane formation from birnessite, perhaps aided by oxidation-state differences. Transformation among birnessite phases of increasing surface area favors compositions with lower surface energy. These quantitative thermodynamic findings explain and support qualitative observations of phase-transformation patterns gathered from natural and synthetic manganese oxides.

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27

Neal, C. "The mineralogy and chemistry of fine-grained sediments, Morphou Bay, Cyprus." Hydrology and Earth System Sciences 6, no. 5 (2002): 819–31. http://dx.doi.org/10.5194/hess-6-819-2002.

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Abstract. The mineralogy and chemistry of the less than 20μm fraction of marine sediments at Morphou Bay, north-west Cyprus, are presented to characterise fine-grained sediment supplies from basic and ultrabasic rocks of the Troodos Massif within a typological setting. The sediments comprise a mixture of smectite, illite, kaolinite and iron rich chlorite. They also contain amorphous iron oxides/hydroxides, calcite (with some magnesium substitution for calcium) and an amphibole. Spatial patterns in mineralogy occur: the near-shore sediments are rich in smectite, chlorite, amphibole and amorphous iron oxides/hydroxides, while the offshore sediments are rich in illite and calcite. The sediments are calcium, magnesium, iron, aluminium and potassium bearing, due to the presence of significant amounts of calcite (for Ca), clay minerals and aluminium and iron oxides/hydroxides. Potassium is present within the micaceous mineral illite, but it is also contained within other phases that are difficult to pinpoint. Statistical analysis reveals that the chemical composition of the sediments broadly follows the mineralogy with the dominant feature being related to spatial changes in the mineralogy. The patterns of change reflect a three component mix of clay-sized sediment types: (1) localised lithogenous sources rich in smectite with subsidiary amounts of amorphous iron oxides/hydroxides and amphibole, from Cyprus, the Troodos in particular, (2) illite rich and smectite chlorite and chlorite bearing material of lithogenous origin from other parts of the eastern Mediterranean and (3) calcite, mainly of marine origin. Keywords: smectite, illite, chlorite, kaolinite, calcite, sediments, Morphou Bay, Troodos, Cyprus, Mediterranean, calcium, potassium, magnesium, iron, silicon, phosphorus.

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28

Anaekwe, Nicholas Ogbonna, and Yusuf Mi kailu Hassan. "Chemical Evaluation of the Glass Making Potentials of Silica Sand Deposits Along Cross River in Cross River State, South–East of Nigeria." European Journal of Engineering Research and Science 2, no. 6 (2017): 12. http://dx.doi.org/10.24018/ejers.2017.2.6.330.

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Analytical techniques such as X–ray Fluorescence Spectroscopy (XRF) and Atomic Absorption Spectroscopy (AAS) coupled with statistical package for multivariate analyses were used to characterize silica sand deposit obtained along Cross River in Cross River State, South Eastern Nigeria. Samples were collected from five locations along the river which include: Ikom-Okuni, Obubra-Ofumbogha, Abi-Ediba, Biase-Agwagune and Etung-Effraya. The results of analyses revealed that silicon dioxide (SiO2) forms the predominant metal oxide in the entire samples followed by iron oxides (Fe203), sodium oxide (Na20). Other Oxides such as aluminum oxide (AI2O3), potassium oxide (k2O) etc were also present. Further beneficiation of the silica sand samples gave increased silica dioxide content across all the samples and increase and decrease of other metal oxides. The acid demand value (ADV) and pH value of the silica sand determination revealed a moderately low ADV and neutral pH value of all the samples. A correlation between the mean values of SiO2 and Fe2O3 in all the samples across all the sampling locations showed an inverse relationship between SiO2 and Fe2O3. Furthermore, comparison using population t – test of observed mean of SiO2 and Fe2O3, with their observed minimum standard (90.52%, 0.005%) shows that the silica sand samples from Ediba and Agwagune can be used as a source of SiO2 for glass making due to their high SiO2 and low levels of Fe2O3 content.

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29

Peck, Torin C., Charles A. Roberts, and Gunugunuri K. Reddy. "Contrasting Effects of Potassium Addition on M3O4 (M = Co, Fe, and Mn) Oxides during Direct NO Decomposition Catalysis." Catalysts 10, no. 5 (2020): 561. http://dx.doi.org/10.3390/catal10050561.

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While the promotional effect of potassium on Co3O4 NO decomposition catalytic performance is established in the literature, it remains unknown if K is also a promoter of NO decomposition over similar simple first-row transition metal spinels like Mn3O4 and Fe3O4. Thus, potassium was impregnated (0.9–3.0 wt.%) on Co3O4, Mn3O4, and Fe3O4 and evaluated for NO decomposition reactivity from 400–650 °C. The activity of Co3O4 was strongly dependent on the amount of potassium present, with a maximum of ~0.18 [(µmol NO to N2) g−1 s−1] at 0.9 wt.% K. Without potassium, Fe3O4 exhibited deactivation with time-on-stream due to a non-catalytic chemical reaction with NO forming α-Fe2O3 (hematite), which is inactive for NO decomposition. Potassium addition led to some stabilization of Fe3O4, however, γ-Fe2O3 (maghemite) and a potassium–iron mixed oxide were also formed, and catalytic activity was only observed at 650 °C and was ~50× lower than 0.9 wt.% K on Co3O4. The addition of K to Mn3O4 led to formation of potassium–manganese mixed oxide phases, which became more prevalent after reaction and were nearly inactive for NO decomposition. Characterization of fresh and spent catalysts by scanning electron microscopy and energy dispersive X-ray analysis (SEM/EDX), in situ NO adsorption Fourier transform infrared spectroscopy, temperature programmed desorption techniques, X-ray powder diffraction (XRD), Raman spectroscopy, and X-ray photoelectron spectroscopy (XPS) revealed the unique potassium promotion of Co3O4 for NO decomposition arises not only from modification of the interaction of the catalyst surface with NOx (increased potassium-nitrite formation), but also from an improved ability to desorb oxygen as product O2 while maintaining the integrity and purity of the spinel phase.

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30

Liu, Ning, Zhimin Wu, Meng Li, et al. "A novel strategy for constructing mesoporous solid superbase catalysts: bimetallic Al–La oxides supported on SBA-15 modified with KF." Catalysis Science & Technology 7, no. 3 (2017): 725–33. http://dx.doi.org/10.1039/c6cy02334g.

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31

Wang, Xiaozhe, Zhiwu Yan, Rongrong Wang, Donghui Liu, Jianliang Zhang, and Zhengjian Liu. "Study of the enrichment characteristics of sinter by alkali metal vapors." Metallurgical Research & Technology 115, no. 3 (2018): 310. http://dx.doi.org/10.1051/metal/2018014.

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The existence forms and distributions of potassium (K) and sodium (Na) in sinter were studied by simulating the actual situations of K and Na cycle and enrichment in the blast furnace (BF). The results show that the K and Na vapor reacted with the main phase of the sinter and formed two “enrichment layers” in periphery, then the sinter samples were analyzed by means of XRD and SEM. The analysis results indicate that the main phases in light “enrichment layer” are K and Na compounds (ferrite, silicates and aluminates), iron oxide (Fe2O3) and silico-ferrite of calcium and aluminum (SFCA); while the dark “enrichment layer” mainly exists the potassium and sodium oxides. In addition, the adsorption of the sinter on K and Na vapor is the mixed adsorption of chemical and physical, and the chemical adsorption is the main adsorption method.

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32

Fuller, MW, KMF Lebrocq, E. Leslie, and IR Wilson. "The Photolysis of Aqueous-Solutions of Potassium Hexacyanoferrate(III)." Australian Journal of Chemistry 39, no. 9 (1986): 1411. http://dx.doi.org/10.1071/ch9861411.

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The photolysis of aqueous solutions of potassium hexacyanoferrate(III) at 254 and 366 nm forms aqua- or hydroxo-pentacyanoferrate(III) in both acidic and alkaline solutions, with quantum yields between 0.02 and 0.06. Subsequent thermal reactions form the decacyanodiferrate(III) and/or decacyanodiferrate(III,II) species, especially in weakly acidic solutions, and, in alkaline solutions, may precipitate hydrated iron(III) oxides.

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33

Stephens, David E., Johant Lakey-Beitia, Jessica E. Burch, Hadi D. Arman, and Oleg V. Larionov. "Mechanistic insights into the potassium tert-butoxide-mediated synthesis of N-heterobiaryls." Chemical Communications 52, no. 64 (2016): 9945–48. http://dx.doi.org/10.1039/c6cc04816a.

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34

Karásková, Kateřina, Kateřina Pacultová, Anna Klegova, et al. "Magnesium Effect in K/Co-Mg-Mn-Al Mixed Oxide Catalyst for Direct NO Decomposition." Catalysts 10, no. 8 (2020): 931. http://dx.doi.org/10.3390/catal10080931.

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Emission of nitric oxide represents a serious environmental problem since it contributes to the formation of acid rain and photochemical smog. Potassium-modified Co-Mn-Al mixed oxide is an effective catalyst for NO decomposition. However, there are problems related to the thermal instability of potassium species and a high content of toxic and expensive cobalt. The reported research aimed to determine whether these shortcomings can be overcome by replacing cobalt with magnesium. Therefore, a series of Co-Mg-Mn-Al mixed oxides with different Co/Mg molar ratio and promoted by various content of potassium was investigated. The catalysts were thoroughly characterized by atomic absorption spectroscopy (AAS), temperature-programmed reduction by hydrogen (TPR-H2), temperature-programmed desorption of CO2 (TPD-CO2), X-ray powder diffraction (XRD), N2 physisorption, species-resolved thermal alkali desorption (SR-TAD), and tested in direct NO decomposition with and without the addition of oxygen and water vapor. Partial substitution of magnesium for cobalt did not cause an activity decrease when the optimal molar ratio of K/Co on the normalized surface area was maintained; it means that the portion of expensive and toxic cobalt can be successfully replaced by magnesium without any decrease in catalytic activity.

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35

Roupcová, Petra, Karel Klouda, Markéta Weisheitelová, and Bohdan Filipi. "Preparation of Material Based on Biochar - MnOx, Its Morphology, Thermal Stability and Phytotoxicity." TRANSACTIONS of the VŠB – Technical University of Ostrava, Safety Engineering Series 13, no. 1 (2018): 21–28. http://dx.doi.org/10.2478/tvsbses-2018-0004.

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Abstract By reducing potassium permanganate using various methods (microwave radiation, HCl, ethanol, ascorbic acid) in a biochar environment, we have prepared composites of manganese oxides and biochar as an electrode material for elements or supercapacitors. Once identified, the prepared products were tested for thermal stability and phytotoxicity as a safety parameter in case they get in contact with the natural environment. The publication had also discussed progression of thermal decomposition of the composite. The process was exo-thermal with mutual oxidation-reduction reaction between the manganese oxides and biochar carbon. In the article there are also described the adsorption capabilities of prepared products. The manganese oxide content had also influenced the phytotoxicity test results. The biochar itself had stimulating effects on all tested seeds, while composites had shown both stimulating and inhibiting effects, depending on the kind of tested seeds.

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36

Li, Mengli, Xing Li, Honghong Chang, Wenchao Gao, and Wenlong Wei. "Palladium-catalyzed direct C–H arylation of pyridine N-oxides with potassium aryl- and heteroaryltrifluoroborates." Organic & Biomolecular Chemistry 14, no. 8 (2016): 2421–26. http://dx.doi.org/10.1039/c5ob02409a.

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An efficient ligand-free Pd(OAc)<sub>2</sub>-catalyzed selective arylation of pyridine N-oxides using potassium (hetero)aryltrifluoroborates as coupling partners via C–H bond activation was achieved in the presence of TBAI.

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37

Zhang, Yunchang, Girish Kshirsagar, John E. Ellison, and James C. Cannon. "Catalytic effects of metal oxides on the decomposition of Potassium perchlorate." Thermochimica Acta 278 (May 1996): 119–27. http://dx.doi.org/10.1016/0040-6031(95)02793-9.

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38

Salem, S. M., and S. A. Tariq. "Molten potassium pyrosulphate: Reactions of oxides of ten main-group elements." Thermochimica Acta 307, no. 2 (1997): 123–25. http://dx.doi.org/10.1016/s0040-6031(97)00297-9.

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39

DOU, Zhe, Hai-jie ZHANG, Yan-fei PAN, and Xiu-feng XU. "Catalytic decomposition of N2O over potassium-modified Cu-Co spinel oxides." Journal of Fuel Chemistry and Technology 42, no. 2 (2014): 238–45. http://dx.doi.org/10.1016/s1872-5813(14)60016-5.

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40

Shimizu, Masahiro, Ryosuke Yatsuzuka, Taro Koya, Tomohiko Yamakami, and Susumu Arai. "Tin Oxides as a Negative Electrode Material for Potassium-Ion Batteries." ACS Applied Energy Materials 1, no. 12 (2018): 6865–70. http://dx.doi.org/10.1021/acsaem.8b01209.

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41

Tondys, Hanna, and Henk C. Van Der Plas. "Amination of 4-nitropyridazine 1-oxides by liquid ammonia/potassium permanganate." Journal of Heterocyclic Chemistry 23, no. 2 (1986): 621–23. http://dx.doi.org/10.1002/jhet.5570230263.

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42

Chen, Xiaopei, Fangfang Yang, Xiuling Cui, and Yangjie Wu. "Potassium Hydroxide-Catalyzed Alkynylation of Heteroaromatic N-Oxides with Terminal Alkynes." Advanced Synthesis & Catalysis 359, no. 22 (2017): 3922–26. http://dx.doi.org/10.1002/adsc.201700931.

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43

Yamamoto, Tatsuhiro, Kenji Kamishima, Koichi Kakizaki, and Nobuyuki Hiratsuka. "Preparation of novel potassium, lanthanum-iron oxides and their magnetic properties." Transactions of the Materials Research Society of Japan 37, no. 2 (2012): 271–74. http://dx.doi.org/10.14723/tmrsj.37.271.

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44

Vdovin, V. V., A. I. Edil’baev, V. A. Kozlov, et al. "Thermodynamic analysis of the reaction of vanadium oxides with oxides of sodium, potassium, calcium, barium, and manganese." Steel in Translation 37, no. 9 (2007): 787–91. http://dx.doi.org/10.3103/s096709120709015x.

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45

Liu, Shuilian, Jian Ji, Yi Yu, and Haibao Huang. "Facile synthesis of amorphous mesoporous manganese oxides for efficient catalytic decomposition of ozone." Catalysis Science & Technology 8, no. 16 (2018): 4264–73. http://dx.doi.org/10.1039/c8cy01111g.

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Amorphous mesoporous manganese oxides (MnO<sub>x</sub>) with different microstructures were synthesized via a facile redox method between manganese acetate and potassium permanganate by modulating the addition sequence of the precursors and directly used for catalytic decomposition of ozone.

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46

Giencke, Wolfgang. "Synthese neuer 2-Dichlormethylen-thiazolidinon-Derivate / Synthesis of New 2-Dichloromethylene-thiazolidinone Compounds." Zeitschrift für Naturforschung B 40, no. 5 (1985): 651–55. http://dx.doi.org/10.1515/znb-1985-0515.

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Abstract Starting from the 2-trichloromethyl-thiazolidinones 3 and 4 syntheses of the 2-dichloromethy-lene-4-thiazolidinones 5 and the corresponding 1-oxides, 6, 9 and 10 are described. The base used in these elimination reactions is potassium-1,2,4-triazole.

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47

Gálvez, Francisco, Marta Cabello, Pedro Lavela, Gregorio F. Ortiz, and José L. Tirado. "Sustainable and Environmentally Friendly Na and Mg Aqueous Hybrid Batteries Using Na and K Birnessites." Molecules 25, no. 4 (2020): 924. http://dx.doi.org/10.3390/molecules25040924.

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Sodium and magnesium batteries with intercalation electrodes are currently alternatives of great interest to lithium in stationary applications, such as distribution networks or renewable energies. Hydrated laminar oxides such as birnessites are an attractive cathode material for these batteries. Sodium and potassium birnessite samples have been synthesized by thermal and hydrothermal oxidation methods. Hybrid electrochemical cells have been built using potassium birnessite in aqueous sodium electrolyte, when starting in discharge and with a capacity slightly higher than 70 mA h g−1. Hydrothermal synthesis generally shows slightly poorer electrochemical behavior than their thermal counterparts in both sodium and potassium batteries. The study on hybrid electrolytes has resulted in the successful galvanostatic cycling of both sodium birnessite and potassium birnessite in aqueous magnesium electrolyte, with maximum capacities of 85 and 50 mA h g−1, respectively.

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48

Black, DS, and KL Ooi. "Nitrones and Oxaziridines. XXXVI. Synthesis of Cyclic Thiohydroxamic Acids." Australian Journal of Chemistry 41, no. 1 (1988): 37. http://dx.doi.org/10.1071/ch9880037.

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2-Cyano-1-pyrroline 1-oxides (1) could not be converted directly into the related cyclic thiohydroxamic acids (8). Potassium ethyl xanthate transformed nitrones (1) into the imidates (2). The cyclic hydroxamic acids (4) can be converted into the thiohydroxamic acids (8) via the methoxypyrrolidinones (5) and the methoxypyrrolidine thiones (6), making use of sodium p- tolylmercaptide as the demethylating agent. Reaction of methoxy thiones (6) with trimethylsilyl iodide led to the formation of the 2-methylthio-1-pyrroline 1-oxides (7).

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49

Skidmore, T. A., and S. J. Milne. "Phase development during mixed-oxide processing of a [Na0.5K0.5NbO3]1−x–[LiTaO3]x powder." Journal of Materials Research 22, no. 8 (2007): 2265–72. http://dx.doi.org/10.1557/jmr.2007.0281.

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Powders of the solid lead-free piezoelectric ceramic solution [Na0.5K0.5NbO3]1−x–[LiTaO3]x, x = 0.06, were produced using a mixed-oxide process. Phase analysis indicated the formation of an orthorhombic solid solution at 800 °C, which coexisted with intermediate binary niobate and tantalate phases. A tetragonal main-phase solid solution was formed at ⩾950 °C, along with minor quantities of a tungsten bronze phase. Addition of 3 wt% excess alkali carbonates to the starting powders allowed the orthorhombic solid solution to be retained to 1100 °C and prevented formation of the secondary tungsten bronze phase. Elemental chemical analysis confirmed changes in alkali oxide composition, consistent with volatilization losses, particularly of potassium and lithium oxides. Phase stability near the reported morphotropic phase boundary is shown to be sensitive to alkali oxide content.

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50

Perry, D. L., A. C. Thompson, R. E. Russo, X. L. Mao, and K. L. Chapman. "Characterization of Quaternary Metal Oxide Films by Synchrotron X-ray Fluorescence Microprobe." Applied Spectroscopy 51, no. 12 (1997): 1781–83. http://dx.doi.org/10.1366/0003702971939749.

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A synchrotron X-ray fluorescence microprobe has been used to study the composition and microstructure of pulsed-laser ablation-deposited films of calcium–nickel–potassium oxides that have applications in heterogeneous catalysis. The films, whose individual metal oxide components have widely varying boiling points and thus prevent a solid-phase synthesis with the use of standard thermal techniques, represent a new quaternary metal oxide phase containing the three elements. Experimental conditions for preparing the films are given. The X-ray fluorescence microprobe data are discussed with respect to both the distribution of the three metals in the films at the micrometer lateral spatial resolution level and the presence of trace amounts of metals that were introduced into the films as contaminants in targets made of the parent three-metal oxide.

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