Journal articles: 'Al2O3 catalysts'

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Thassanaprichayanont, Sildara, Duangduen Atong, and Viboon Sricharoenchaikul. "Preparation of Ni – MgO– La₂O₃ Catalyst on Alumina Support for Catalytic Tar Cracking Process." Key Engineering Materials 434-435 (March 2010): 826–29. http://dx.doi.org/10.4028/www.scientific.net/kem.434-435.826.

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This study reported the synthesis of Ni -based catalysts on Al2O3 support carried out by two different methods including co-impregnation and sequential impregnation. Different nitrate solutions of nickel, lanthanum, and magnesium were used for support impregnation. The calination process was carried out at 650 °C and 850 °C for 2 h under air. The XRD patterns of the catalyst samples presented main phases of Al2O3 and other diffraction lines corresponding to metal and oxide promoters; Ni, MgO and/or NiO, (Ni,Mg)Al2O4, La2O3 and La(AlO3). Prepared catalysts appeared in irregular shaped agglomerates of small particles of less than 1 micron. Surface area of co-impregnated catalysts increased with increasing calcination temperature while ones from sequential impregnation decreased except for those last impregnated with nickel salts. The La2O3-MgO-Ni/Al2O3 sequential impregnated catalyst had the highest surface area of 8.0-8.5 m2/g.

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Mardwita, Mardwita, Eka Sri Yusmartini, and Nidya Wisudawati. "Effects of Calcination Temperatures on The Catalytic Activities of Alumina Supported Cobalt and Chromium Catalysts." Bulletin of Chemical Reaction Engineering & Catalysis 14, no. 3 (December 1, 2019): 654. http://dx.doi.org/10.9767/bcrec.14.3.4673.654-659.

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Catalysts properties are important for catalytic reactions. The interaction between support and metal in a catalyst is resulted from catalyst preparation. In this study, gamma-alumina (Al2O3) supported cobalt (Co) and chromium (Cr) catalysts were prepared by impregnation method and calcined at two different temperatures, they are 400 °C for 4 hours and 800 °C for 4 hours. The resulted catalysts contained 10 wt.% of metal and denoted as Co/Al2O3(400), Co/Al2O33(800), Cr/Al2O3(400), and Cr/Al2O3(800) catalysts. The surface and state of the catalysts were examined by using x-ray diffraction (XRD), x-ray photoelectron spectrometer (XPS) and transmission electron microscopy (TEM). The XRD result reveals that strong interaction between Co and Al2O3 due to a formation of higher cobalt oxide. The XRD result further indicates aggregation and strong support metal interaction between Co and Al2O3 during calcination. On the other hand, TEM result showed that large Co particle was observed on Al2O3. The Cr/Al2O3 catalysts were characterized by using XPS. The XPS results showed that Cr/Al2O3(800) catalyst was dominated by Cr6+ species at binding energy 579.04 eV, indicating high dispersion of Cr on Al2O3. Moreover, Cr metal particle was not observed on XRD and TEM image. All the characterization results provide information that the impregnated metal on Al2O3 showed different properties. Co metal particle tends to be more oxidized and formed large particle, however it was not observed on Cr metal particle. Copyright © 2019 BCREC Group. All rights reserved

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Haerudin, Hery, Wihatmoko Waskitoaji, and Usman Usman. "EFFECT OF THE REDUCTION TEMPERATURE INTO CATALYTIC ACTIVITY OF Ni SUPPORTED BY TiO₂, AL₂O₂ AND TiO₂/AL₂O₃ FOR CONVERSION CO₂ INTO METHANE." Indonesian Journal of Chemistry 3, no. 1 (June 7, 2010): 24–31. http://dx.doi.org/10.22146/ijc.21902.

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Nickel catalysts, containing 6% (w/w) of nickel, have been prepared using TiO2, Al2O3 and mixture of TiO2-Al2O3 (1:9). The catalysts were used for CO2 conversion into methane. The characteristics of catalysts were studied by determination of its specific surface area, temperature programmed reaction technique and X-ray diffraction. The specific surface area were varied slightly by different temperature of reduction, namely after reduction at 300°C it was 39, 120 and 113 m2/g and after reduction at 400°C it was 42, 135 and 120 m2/g for 6% nickel catalysts supported on TiO2, Al2O3 and mixture of TiO2-Al2O3 (1:9) respectively. Temperature program reaction studies (TPO and TPR) showed that NiTiOx species were possibly formed during the pretreatments which has shown by the shift of its peak to the lower temperature on Ni catalyst, that supported on mixture of TiO2-Al2O3 compared with catalysts supported on individual TiO2 or Al2O3. The nickel species on reduced Ni catalysts supported on TiO2 and on mixture of TiO2-Al2O3 could be detected by X-ray diffraction. The catalyst's activities toward CH4 formation were affected by the reduction temperature. Activity for CH4 formation was decreased in the following order: Ni/ TiO2 > Ni/ TiO2: Al2O3 > Ni/ Al2O3 and Ni/ TiO2: Al2O3 > Ni/ TiO2> Ni/ Al2O3, when catalysts were reduced at 300°C or 400°C respectively. The CO2 conversion was decreased in the following order: Ni/ Al2O3 > Ni/ TiO2: Al2O3 > Ni/ TiO2 when catalysts were reduced at 300°C or 400°C respectively. Keywords: nickel catalyst, carbondioxide, methane

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Fertal, Domenica R., Maxim P. Bukhovko, Yong Ding, Mehmet Z. Billor, and Anil C. Banerjee. "Particle Size and PdO–Support Interactions in PdO/CeO2-γ Al2O3 Catalysts and Effect on Methane Combustion." Catalysts 10, no. 9 (August 30, 2020): 976. http://dx.doi.org/10.3390/catal10090976.

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In this study, we investigated the effects of sequential impregnation in two PdO/CeO2/Al2O3 nanocatalysts (4Pd-20CeO2/Al2O3 and 20CeO2-4Pd/Al2O₃) on catalytic properties, particle sizes, and metal oxide–support interactions. Pulse chemisorption indicated significantly higher dispersion and smaller particle size in the 20CeO2-4Pd/Al2O₃ catalyst. STEM images of the 4Pd-20CeO2/Al2O₃ catalyst showed PdO nanoparticles on the surface of crystalline Al2O₃. In the 20CeO2-4Pd/Al2O3 catalyst, PdO nanoparticles were strongly embedded on ceria indicating PdO-ceria interactions. Both supports were on separate sites in the two catalysts suggesting weak interactions. PdO particle sizes were 6–12 nm in the 4Pd-20CeO2/Al2O₃ catalyst and 4–8 nm in the 20CeO2-4Pd/Al2O₃ catalyst. Methane conversion was 100% at 275 °C after a 20-min run with the 4Pd-20CeO2/Al2O3 catalyst compared to 25% conversion by the 20CeO2-4Pd/Al2O₃ catalyst under same conditions. The support alumina could stabilize the PdO species and facilitated oxygen migration on the surface and from the bulk in the 4Pd-20CeO2/Al2O3 catalyst. The lower activities in the 20CeO2-4Pd/Al2O₃ catalyst could be due to inaccessibility of PdO active sites at low temperature due to embedment of PdO nanoparticles on ceria. We could infer from our data that sequence of impregnation in catalyst synthesis could significantly influence catalytic properties and methane combustion due to PdO–support interactions.

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Yang, Haobo, Jichao Li, Hao Yu, Feng Peng, and Hongjuan Wang. "Metal-Foam-Supported Pd/Al2O3 Catalysts for Catalytic Combustion of Methane: Effect of Interaction between Support and Catalyst." International Journal of Chemical Reactor Engineering 13, no. 1 (March 1, 2015): 83–93. http://dx.doi.org/10.1515/ijcre-2014-0009.

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Abstract Structured Pd/Al2O3 catalysts were fabricated by impregnating Pd onto Ni and Cu foams coated with Al2O3 layers. By testing the adhesion stability and catalytic activity in the combustion of methane, the superior performance of Ni-foam-supported Pd/Al2O3 catalyst was demonstrated, to its counterpart powder catalysts. The resultant structured catalysts enable the fabrication of lamellar microreactor systems. It is found that the metal foams influence the activity of catalyst layer, due to the diffusive penetration of metallic atoms into catalysts from metal foams. The Ni foam is beneficial for enhancing the activity of Pd/Al2O3 catalyst, while the Cu foam plays a negative role. The investigation to the model powder catalysts doped with Ni and Cu verified the modification of Ni and Cu to the physicochemical properties of Pd/Al2O3 catalyst, thereby the catalytic performances. Thus, it can be expected that the performance of structured catalysts may be improved by rationally designing and selecting proper supports.

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Pudi, Satyanarayana Murty, Tarak Mondal, Prakash Biswas, Shalini Biswas, and Shishir Sinha. "Conversion of Glycerol into Value-Added Products Over Cu–Ni Catalyst Supported on γ-Al2O3 and Activated Carbon." International Journal of Chemical Reactor Engineering 12, no. 1 (January 1, 2014): 151–62. http://dx.doi.org/10.1515/ijcre-2013-0102.

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Abstract A series of Cu, Ni monometallic and bimetallic catalysts supported on γ-Al2O3 and activated carbon were synthesized by incipient wetness impregnation method and examined for hydrogenolysis and esterification of glycerol. Hydrogenolysis reaction was carried out in a 250 ml Teflon-coated stainless steel batch reactor at 250°C and 10 bar H2 pressure, whereas esterification of glycerol with acetic acid was carried out at 120°C at atmospheric pressure. The physiochemical properties of the catalysts were investigated by various techniques such as surface area, X-ray diffraction (XRD), NH3-temperature-programmed desorption (TPD). Characterization results dictated that the reduction behavior, acidic nature and the metal support interactions were varied with the support as well as Cu/Ni weight ratio. The XRD results confirmed the formation of mixed oxide Cu0.75Ni0.25 Al2O4 phase in Cu–Ni (3:1)/γ-Al2O3 catalyst. Among the catalysts tested, Cu–Ni bimetallic catalysts showed superior performance as compared to monometallic catalysts in both the reactions. The glycerol hydrogenolysis activity of γ-Al2O3 supported Cu–Ni catalysts was higher than the activated carbon-supported catalysts. 1,2-PDO was obtained as the main hydrogenolysis product independent of the support as well as Cu/Ni weight ratio and its selectivity was in the range of 92.8–98.5%. The acidic nature of γ-Al2O3 and the mixed oxide (Cu0.75Ni0.25Al2O4) phase played an important role for hydrogenolysis activity. Cu–Ni (3:1)/γ-Al2O3 catalyst showed the maximum 1,2-PDO selectivity to 97% with 27% glycerol conversion after a reaction time of 5 h. On the other hand, Cu–Ni(1:3)/C catalyst showed the highest glycerol conversion of 97.4% for esterification and obtained selectivity to monoacetin, diacetin and triacetin were 26.1%, 67.2% and 6.5%, respectively.

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Yang, Shao Xia, Yu Jie Feng, Jiafeng Wan, Wanpeng Zhu, and Zhanpeng Jiang. "Effect of TiO₂ on the Property of RuO₂/γ-Al₂O₃ Catalyst." Materials Science Forum 475-479 (January 2005): 1141–44. http://dx.doi.org/10.4028/www.scientific.net/msf.475-479.1141.

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A catalyst, as a kind of function material, plays important roles. In the paper RuO2/g-Al2O3 and RuO2-TiO2/g-Al2O3 catalyst were prepared by the impregnation method. The structure o f two catalysts was studied with XRD, SEM and XPS. The addition of TiO2 promoted the dispersion of Ru particles, and made the amount of the chemisorbed oxygen increased on catalyst surface. The activity was investigated in WAO of phenol over RuO2/g-Al2O3 and RuO2-TiO2/g-Al2O3 catalysts. The results showed that two catalysts had good activity, and TiO2 effectively increased the activity of RuO2/g-Al2O3 catalyst in WAO of phenol. With RuO2-TiO2/g-Al2O3 catalyst 96% phenol removal was observed at 150°C and 3MPa after 80min reaction in WAO of phenol.

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Do Pham Noa, Uy, Huan Nguyen Manh, Loc Hoang Van, Chien Luc Minh, Giang Nguyen Thi Chau, Nhan Truong Van, Binh Phan Minh Quoc, Luong Nguyen Huu, and Thuan Huynh Minh. "Fischer-Tropsch synthesis over Co/γ-Al2O3 catalyst loaded on ceramic monolith-structured substrate." Vietnam Journal of Catalysis and Adsorption 9, no. 3 (October 2, 2020): 88–93. http://dx.doi.org/10.51316/jca.2020.055.

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Cobalt-based catalyst supported on γ-Al2O3 was prepared by impregnation method and loaded on ceramic monolith-structured substrate by wash-coating slurry method. Physico-chemical properties of the catalysts were characterized by X-ray diffraction (XRD), Brunauer–Emmett–Teller (BET) specific surface area and H2 temperatured-programmed reduction (H2-TPR). Activity of the catalysts for Fischer-Tropsch synthesis was investigated in a tubular reactor in a temperature range of 200-275 oC at 20 bar and GHSV = 3000 h-1. Co/γ-Al2O3 catalyst loaded on ceramic monolith-structured substrate enhanced efficacy of Fischer-Tropsch synthesis by increasing and stabilizing CO conversion and C5+ selectivity, compared to Co/γ-Al2O3 powder catalyst.

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Tuktin B.T.,, Shapovalova L.B.,, Tenizbayeva A.A.,, Abilmagzhanov A.Z.,, and Egizbaeva R.I.,. "HYDROTREATING AND HYDROISOMERIZATION OF OIL FRACTIONS ON MODIFIED ALUMINUM-COBALTMOLYBDENUM CATALYSTS." SERIES CHEMISTRY AND TECHNOLOGY 5, no. 443 (October 2020): 99–107. http://dx.doi.org/10.32014/2020.2518-1491.86.

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In this work we are given results and research of hydro refining of gasoline and diesel oil fractions on alumina catalysts CoO-MoO3-La2О3-Р2О5-ZSM-Al2O3, CoO-MoO3-Ce2О3-Р2О5-ZSM-HY-Al2O3, CoO-MoO3-La2О3-Р2О5- AAC-ZSM -Al2O3. The catalysts were prepared by impregnating a mixture of aluminum hydroxide and zeolites ZSM-5, HY with aqueous solutions of salts Co, Mo, La and phosphoric acid. Large-scale laboratory tests of the synthesized catalysts were carried out in the process of hydro processing of various types of gasoline and diesel fractions. At hydro treating of straight-run gasoline over CoO-MoO3-La2О3-Р2О5-ZSM-Al2O3 shows that in the temperature range 320 - 350оС the maximum amount of isoalkanes is formed 33.4-40.4%. The octane number of refined gasoline increases in comparison with the initial one from 78.9 to 89.3 (RON) and from 60.9 to 73.4 (MON). The sulfur content of catalysate with increasing temperature up to 400оС decreased to 0.0012 %. At hydro processing of catalytic cracking gasoline on CoO-MoO3-La2О3-Р2О5-ZSM-Al2O3 the octane number of refined gasoline is slightly reduced. The sulfur content of catalysate with increasing temperature up to 400оС decreased from initial with from 0.0134 to 0 0014 %. It was found that the lowest pour point and cloud point of hydro-refined diesel fuel is observed on the catalyst CoO-MoO3-La2O3-P2O5-ZSM-Al2O3. After hydro treating on this catalyst the pour point and cloud point are equal to minus 52.7oC and minus 40.8oC accordingly. This same catalyst has the highest hydro desulfurization activity: the sulfur content decreases from 0.5600% to 0.104%. Thus, the developed modified zeolite-containing catalysts CoO-MoO3-La2О3-P2O5-ZSM-Al2O3, CoO-MoO3-Се2О3-P2O5-ZSM-HY-Al2O3, CoO-MoO3-La2О3-P2O5-AAC-ZSM-Al2O3, exhibiting high activity at hydro treating of gasoline and diesel fractions and is able in one stage deep hydro treating, hydro isomerization and hydrocracking which allows to obtain low-sulfur, high-octane gasoline and low-sulfur and low solidifying diesel fuel which is important for operation of vehicles in winter conditions.

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Lee, Jong Kwon, Hyun Seo, Ung Gi Hong, Gle Park, Yeonshick Yoo, Jinsuk Lee, Hosik Chang, and In Kyu Song. "Platinum-Tin Nano-Catalysts Supported on Alumina for Direct Dehydrogenation of n-Butane." Journal of Nanoscience and Nanotechnology 15, no. 10 (October 1, 2015): 8305–10. http://dx.doi.org/10.1166/jnn.2015.11241.

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Al2O3 supports were prepared by a precipitation method using various basic solutions (NaOH, KOH, NH4OH, and Na2CO3) as precipitation agents, and Pt/Sn/Al2O3 nano-catalysts were then prepared by a sequential impregnation method. The prepared catalysts were applied to the direct dehydrogenation of n-butane to n-butenes and 1,3-butadiene. The effect of precipitation agents on the physicochemical properties and catalytic activities of Pt/Sn/Al2O3 nano-catalysts in the direct dehydrogenation of n-butane was investigated. Catalytic performance of Pt/Sn/Al2O3 nanocatalysts decreased in order of Pt/Sn/Al2O3 (NaOH) > Pt/Sn/Al2O3 (KOH) > Pt/Sn/Al2O3 (NH4OH) > Pt/Sn/Al2O3 (Na2CO3). Among the catalysts tested, Pt/Sn/Al2O3 (NaOH) nano-catalyst showed the best catalytic performance in terms of yield for total dehydrogenation products (TDP, n-butenes and 1,3-butadiene). Hydrogen chemisorption experiments revealed that platinum surface area of the catalyst was closely related to the catalytic performance. Yield for TDP increased with increasing platinum surface area of the catalyst.

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Chomboon, Tanakit, Weerit Kumsung, Metta Chareonpanich, Selim Senkan, and Anusorn Seubsai. "Chromium-Ruthenium Oxides Supported on Gamma-Alumina as an Alternative Catalyst for Partial Combustion of Methane." Catalysts 9, no. 4 (April 4, 2019): 335. http://dx.doi.org/10.3390/catal9040335.

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Catalyst screening of γ-Al2O3-supported, single-metal and bimetallic catalysts revealed several bimetallic catalysts with activities for partial combustion of methane greater than a benchmark Pt/γ-Al2O3 catalyst. A cost analysis of those catalysts identified that the (2 wt%Cr + 3 wt% Ru)/γ-Al2O3 catalyst, denoted as 2Cr3Ru/Al2O3, was about 17.6 times cheaper than the benchmark catalyst and achieved a methane conversion of 10.50% or 1.6 times higher than the benchmark catalyst based on identical catalyst weights. In addition, various catalyst characterization techniques were performed to determine the physicochemical properties of the catalysts, revealing that the particle size of RuO2 became smaller and the binding energy of Ru 3d also shifted toward a lower energy. Moreover, the operating conditions (reactor temperature and O2/CH4 ratio), stability, and reusability of the 2Cr3Ru/Al2O3 catalyst were investigated. The stability test of the catalyst over 24 h was very good, without any signs of coke deposition. The reusability of the catalyst for five cycles (6 h for each cycle) was noticeably excellent.

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Limlamthong, Mutjalin, Nithinart Chitpong, and Bunjerd Jongsomjit. "Influence of Phosphoric Acid Modification on Catalytic Properties of γ-χ Al2O3 Catalysts for Dehydration of Ethanol to Diethyl Ether." Bulletin of Chemical Reaction Engineering & Catalysis 14, no. 1 (April 15, 2019): 1. http://dx.doi.org/10.9767/bcrec.14.1.2436.1-8.

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In this present work, diethyl ether, which is currently served as promising alternative fuel for diesel engines, was produced via catalytic dehydration of ethanol over H3PO4-modified g-c Al2O3 catalysts. The impact of H3PO4 addition on catalytic performance and characteristics of catalysts was investigated. While catalytic dehydration of ethanol was performed in a fixed-bed microreactor at the temperature ranging from 200ºC to 400ºC under atmospheric pressure, catalyst characterization was conducted by inductively coupled plasma (ICP), X-ray diffraction (XRD), N2 physisorption, temperature-programmed desorption of ammonia (NH3-TPD) and thermogravimetric (TG) analysis. The results showed that although the H3PO4 addition tended to decrease surface area of catalyst resulting in the reduction of ethanol conversion, the Al2O3 containing 5 wt% of phosphorus (5P/Al2O3) was the most suitable catalyst for the catalytic dehydration of ethanol to diethyl ether since it exhibited the highest catalytic ability regarding diethyl ether yield and the quantity of coke formation as well as it had similar long-term stability to conventional Al2O3 catalyst. The NH3-TPD profiles of catalysts revealed that catalysts containing more weak acidity sites were preferred for dehydration of ethanol into diethyl ether and the adequate promotion of H3PO4 would lower the amount of medium surface acidity with increasing catalyst weak surface acidity. Nevertheless, when the excessive amount of H3PO4 was introduced, it caused the destruction of catalysts structure, which resulted in the catalyst incapability due to the decrease in active surface area and pore enlargement. Copyright © 2019 BCREC Group. All rights reservedReceived: 28th March 2018; Revised: 7th August 2018; Accepted: 15th August 2018; Available online: 25th January 2019; Published regularly: April 2019How to Cite: Limlamthong, M., Chitpong, N., Jongsomjit, B. (2019). Influence of Phosphoric Acid Modification on Catalytic Properties of g-c Al2O3 Catalysts for Dehydration of Ethanol to Diethyl Ether. Bulletin of Chemical Reaction Engineering & Catalysis, 14 (1): 1-8 (doi:10.9767/bcrec.14.1.2436.1-8)Permalink/DOI: https://doi.org/10.9767/bcrec.14.1.2436.1-8

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Lee, Hae Ri, Kwi Yeon Lee, Nam Cook Park, Jae Soon Shin, Dong Ju Moon, Byung Gwon Lee, and Young Chul Kim. "Production of Hydrogen by Autothermal Reforming of Propane over Ni/δ-Al2O3." Journal of Nanoscience and Nanotechnology 6, no. 11 (November 1, 2006): 3396–98. http://dx.doi.org/10.1166/jnn.2006.019.

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The performance of Ni/δ-Al2O3 catalyst in propane autothermal reforming (ATR) for hydrogen production was investigated in the present study. The catalysts were characterized using XRD, TEM, and SEM. The activity of the Ni/δ-Al2O3 catalyst manufactured by the water-alcohol method was better than those of the catalysts manufactured by the impregnation and chemical reduction methods. The Ni/δ-Al2O3 catalysts were modified by the addition of promoters such as Mg, La, Ce, and Co, in order to improve their stability and yield. Hydrogen production was the largest for the Ni-Co-CeO2/Al2O3 catalyst.

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Kazemnejad, Iraj, Alireza Feizbakhsh, Ali Niazi, and Ahmad Tavasoli. "Highly dispersed cobalt Fischer–Tropsch synthesis catalysts supported on γ-Al2O3, CNTs, and graphene nanosheet using chemical vapor deposition." International Journal of Industrial Chemistry 10, no. 4 (September 26, 2019): 321–33. http://dx.doi.org/10.1007/s40090-019-00195-9.

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Abstract Highly dispersed 15.0 wt% cobalt catalysts were prepared on γ-Al2O3, carbon nanotubes (CNTs), and graphene nanosheet (GNS) using chemical vapor deposition (CVD) procedure. The physico-chemical properties of the catalysts were studied by inductively coupled plasma (ICP), Brunauer–Emmett–Teller (BET), X-ray powder diffraction (XRD), field-emission scanning electron microscopy (FESEM), and temperature-programmed reduction (TPR) techniques, and the Fischer–Tropsch synthesis (FTS) performance of the catalysts was assessed at 220 °C, 18 bar, H2/CO = 2 and feed flow rate of 45 ml/min g cat. Based on BET results, Co/GNS catalyst provided highest surface area in comparison to the other catalysts. XRD and FESEM results revealed that CVD method prepared smaller particles on GNS compared to the other supports and resulted in the most dispersed metal particles on GNS according to H2-chemisorption results. The performance of Co/Al2O3 catalyst prepared by CVD method was compared with conventional 15 wt% Co/Al2O3 catalyst prepared by impregnation method. The Co/Al2O3 catalyst prepared with CVD method showed 5.3% higher %CO conversion and 2.1% lower C5+ selectivity as compared with the Co/Al2O3 catalysts prepared by impregnation method. Among three catalysts prepared by CVD, Co/GNS showed higher %CO conversion of 78.4% and C5+ selectivity of 70.3%. Co/γ-Al2O3 catalyst showed higher stability.

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Shtyka, O., Z. Dimitrova, R. Ciesielski, A. Kedziora, G. Mitukiewicz, J. Leyko, W. Maniukewicz, A. Czylkowska, and T. Maniecki. "Steam reforming of ethanol for hydrogen production: influence of catalyst composition (Ni/Al2O3, Ni/Al2O3–CeO2, Ni/Al2O3–ZnO) and process conditions." Reaction Kinetics, Mechanisms and Catalysis 132, no. 2 (March 4, 2021): 907–19. http://dx.doi.org/10.1007/s11144-021-01945-6.

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AbstractEthanol steam reforming was studied over Ni supported catalysts. The effects of support (Al2O3, Al2O3–ZnO, and Al2O3–CeO2), metal loading, catalyst activation method, and steam-to-ethanol molar feed ratio were investigated. The properties of catalysts were studied by N2 physisorption, TPD-CO2, X-ray diffraction, and temperature programmed reduction. After activity tests, the catalysts were analyzed by TOC analysis. The catalytic activity measurements showed that the addition either of ZnO SSor CeO2 to alumina enhances both ethanol conversion and promotes selectivity towards hydrogen formation. The same effects were observed for catalysts with higher metal loadings. High process temperature and high water-to-ethanol ratio were found to be beneficial for hydrogen production. An extended catalyst stability tests showed no loss of activity over 50 h on reaction stream. The TOC analysis of spent catalysts revealed only insignificant amounts of carbon deposit.

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Lokman NolHakim, Muhammad Amirrul Hakim, Norshahidatul Akmar Mohd Shohaimi, Wan Nur Aini Wan Mokhtar, Mohd Lokman Ibrahim, and Rose Fadzilah Abdullah. "Immobilization of Potassium-Based Heterogeneous Catalyst over Alumina Beads and Powder Support in the Transesterification of Waste Cooking Oil." Catalysts 11, no. 8 (August 15, 2021): 976. http://dx.doi.org/10.3390/catal11080976.

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In this work, the beads and powder potassium hydroxide (KOH) and potassium carbonate (K2CO3) supported on alumina oxide (Al2O3) were successfully prepared via incipient wetness impregnation technique. Herein, the perforated hydrophilic materials (PHM) made from low-density polyethylene (LDPE) was used as the catalyst reactor bed. The prepared catalysts were investigated using TGA, XRD, BET, SEM-EDX, TPD, FTIR while spent catalysts were analyzed using XRF and ICP-AES to study its deactivation mechanism. The catalytic performance of beads and powder KOH/Al2O3 and K2CO3/Al2O3 catalysts were evaluated via transesterification of waste cooking oil (WCO) to biodiesel. It was found that the optimum conditions for transesterification reaction were 1:12 of oil-to-methanol molar ratio and 5 wt.% of catalyst at 65 °C. As a result, the mesoporous size of beads KOH/Al2O3 and K2CO3/Al2O3 catalysts yielded 86.8% and 77.3% at 2 h’ reaction time of fatty acids methyl ester (FAME), respectively. It was revealed that the utilization of PHM for beads K2CO3/Al2O3 increase the reusability of the catalyst up to 7 cycles. Furthermore, the FAME produced was confirmed by the gas chromatography-mass spectroscopic technique. From this finding, beads KOH/Al2O3 and K2CO3/Al2O3 catalysts showed a promising performance to convert WCO to FAME or known as biodiesel.

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Mierczynski, Paweł, Piotr Kaczorowski, Agnieszka Ura, Waldemar Maniukiewicz, Marcin Zaborowski, Radoslaw Ciesielski, Adam Kedziora, and Tomasz Maniecki. "Promoted ternary CuO-ZrO2-Al2O3 catalysts for methanol synthesis." Open Chemistry 12, no. 2 (February 1, 2014): 206–12. http://dx.doi.org/10.2478/s11532-013-0368-3.

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AbstractTernary CuO-ZrO2-Al2O3 catalysts promoted by palladium or gold were prepared and tested in CO hydrogenation reaction at 260°C under elevated pressure (4.8 MPa). The promotion effect of palladium or gold addition on the physicochemical and catalytical properties of CuO-ZrO2-Al2O3 catalysts in methanol synthesis (MS) was studied. The catalysts were characterized by BET, XRD, TPR-H2, TPD-NH3 methods. The BET results showed that the ternary system CuO-ZrO2-Al2O3 had the largest specific surface area, cumulative pore volume and average pore size in comparison with the promoted catalysts. The yield of methanol can be given through the following sequence: 5%Pd/CuO-ZrO2-Al2O3 > CuO-ZrO2-Al2O3 > 2%Au/CuO-ZrO2-Al2O3. We also found that the presence of gold or palladium on catalyst surface has strong influence on the reaction selectivity. The high selectivity of gold doped ternary catalyst is explained by the gold-oxide interface sites created on the catalyst surface and the acidity of those systems. The higher selectivity to methanol in the case of the palladium catalyst is explained by the spillover effect between Pd and CuO.

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Velea, Sanda, Mihaela Bombos, Gabriel Vasilievici, Rami Doukeh, and Dorin Bombos. "Component for Gasoline by Hydroconversion of Furfural Derivates in Presence of Methanol." Revista de Chimie 68, no. 7 (August 15, 2017): 1512–17. http://dx.doi.org/10.37358/rc.17.7.5706.

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Hydrotreating of furfural in order to obtain furan derivatives, components for gasoline was studied on two catalysts Ni-Co-Mo /g-Al2O3 promoted with Ba and respectively Pt-Pd/g-Al2O3. Catalysts characterization where performed by determining the acid strength and textural characteristics. For both catalysts the main reaction products identified are tetrahydrofurfuryl alcohol, methyl tetrahydrofurfuryl ether, furfuryl alcohol and furfuryl methyl ether, the most valuable component for gasoline from the resulting mixture being tetrahydrofurfuryl methyl ether. Catalyst Pt-Pd/g-Al2O3 showed higher activity than catalyst Ni-Co-Mo-Ba /g-Al2O3 on the ranges of parameters studied. The yield in ethers was higher than the yield in alcohols for both catalysts for the parameters range studied and the yield in tetrahydrofurfuryl methyl ether was higher in the case of Pd-Pt catalyst than for Ni-Co-Mo-Ba catalyst.

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Nevanperä, Tuomas K., Satu Pitkäaho, Satu Ojala, and Riitta L. Keiski. "Oxidation of Dichloromethane over Au, Pt, and Pt-Au Containing Catalysts Supported on γ-Al2O3 and CeO2-Al2O3." Molecules 25, no. 20 (October 12, 2020): 4644. http://dx.doi.org/10.3390/molecules25204644.

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Au, Pt, and Pt-Au catalysts supported on Al2O3 and CeO2-Al2O3 were studied in the oxidation of dichloromethane (DCM, CH2Cl2). High DCM oxidation activities and HCl selectivities were seen with all the catalysts. With the addition of Au, remarkably lower light-off temperatures were observed as they were reduced by 70 and 85 degrees with the Al2O3-supported and by 35 and 40 degrees with the CeO2-Al2O3-supported catalysts. Excellent HCl selectivities close to 100% were achieved with the Au/Al2O3 and Pt-Au/Al2O3 catalysts. The addition of ceria on alumina decreased the total acidity of these catalysts, resulting in lower performance. The 100-h stability test showed that the Pt-Au/Al2O3 catalyst was active and durable, but the selectivity towards the total oxidation products needs improvement. The results suggest that, with the Au-containing Al2O3-supported catalysts, DCM decomposition mainly occurs via direct DCM hydrolysis into formaldehyde and HCl followed by the oxidation of formaldehyde into CO and CO2.

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20

Kiribayashi, Hoshimitsu, Takayuki Fujii, Takahiro Saida, Shigeya Naritsuka, and Takahiro Maruyama. "Effects of Al2O3 Type on Activity of Al2O3-Supported Rh Catalysts in Single-Walled Carbon Nanotubes Growth by CVD." MRS Advances 2, no. 02 (2017): 89–95. http://dx.doi.org/10.1557/adv.2017.25.

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ABSTRACT We carried out single-walled carbon nanotube (SWCNT) growth using a Rh catalyst on Al2O3 buffer layers that were prepared by three different methods based on electron beam (EB) evaporation: native oxidation of Al layer deposited by EB ([EB(Al)+NO]-Al2O3 layer); thermal oxidation of Al layer deposited by EB ([EB(Al)+TO]-Al2O3 layer); EB deposition of Al2O3 layer ([EB(Al2O3)]-Al2O3 layer). SWCNT yield was the largest for the [EB(Al2O3)]-Al2O3 layer, while SWCNTs were not grown on the [EB(Al)+NO]- Al2O3 layer. Transmission electron spectroscopy showed that most of Rh particle sizes were distributed between 1.0 and 2.6 nm on the [EB(Al)+NO]- Al2O3 and [EB(Al2O3)]- Al2O3 layers, while they were distributed between 1.8 and 4.2 nm on the [EB(Al)+TO]- Al2O3 layer. This result indicates that surface migration of Rh catalysts was suppressed on the [EB(Al2O3)]- Al2O3 layer, resulting in the largest SWCNT yield. On the other hand, enlargement of Rh catalyst particles occurred on the [EB(Al)+TO]- Al2O3 layer, leading to the reduction of SWCNT yield. Taking into account our previous study, inward diffusion of Rh catalysts into the Al2O3 buffer layer inhibited SWCNT growth on the [EB(Al)+NO]- Al2O3 layer, although enlargement of Rh particle size was suppressed. We also carried out ultra-violet photoemission measurements for Rh catalysts on the [EB(Al)+TO]- Al2O3 and [EB(Al2O3)]- Al2O3 layers and investigated the electronic states of Rh catalysts on them.

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21

Temu, A. K. "Biodiesel Production Using Mixed Solid Catalysts." Advanced Materials Research 824 (September 2013): 451–58. http://dx.doi.org/10.4028/www.scientific.net/amr.824.451.

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One of the disadvantages of homogeneous base catalysts in biodiesel production is that they cannot be reused or regenerated because they are consumed in the reaction. Besides, homogeneous catalysed process is not environmentally friendly because a lot of waste water is produced in the separation step. Unlike homogeneous, heterogeneous catalysts are environmentally benign, can be reused and regenerated, and could be operated in continuous processes, thus providing a promising option for biodiesel production. This paper presents catalytic activity of single and mixed solid catalysts in production of biodiesel from palm oil using methanol as well as ethanol at atmospheric pressure. The catalysts used are CaO, K2CO3, Al2O3, and CaO/K2CO3, CaO/Al2O3, K2CO3/Al2O3 mixtures. Results show that methanol is a better reactant with biodiesel yield ranging from 48 to 96.5% while ethanol gives yields ranging from 20 to 95.2%. The yield data for single catalysts range from 20 to 89.2% while that for mixed catalysts range from 52 to 96.5% indicating improvement in the activity by mixing the catalysts. The study also shows that biodiesel yield increases with catalyst loading which emphasizes the need for sufficient number of active sites. The properties of biodiesel produced compares well with ASTM D6751 and EN 14124 biodiesel standards.

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22

Zhang, Jing Cheng, Hai Bin Yu, Jun Nan, Shan Geng, Xiao Guo Li, Xiao Long Qu, Yu Lin Shi, Yu Ting Zhang, and Hong Guang Liu. "Synthesis and Hydrodesulfurization Performance of NiMo Sulfide Catalysts Supported on γ-Al₂O₃." Advanced Materials Research 781-784 (September 2013): 304–7. http://dx.doi.org/10.4028/www.scientific.net/amr.781-784.304.

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This work presents the synthesis and hydrodesulfurization performance of NiMo sulfide catalysts supported on γ-Al2O3 during the hydrodesulfurization (HDS) of dibenzothiophene (DBT). The catalysts were synthesized by the co-impregnation method using an atomic ratio of Ni=Ni/(Ni+Mo)=0.5. The materials were characterized by N2 physisorption, XRD and HRTEM. This catalyst exhibited the larger pore size and high specific surface area, as well as better morphological properties. The catalytic activity was evaluated using a high-pressure batch reactor at 280 °C and 3.0 MPa. The catalytic activity during HDS-DBT indicated that the NiMoS/γ-Al2O3 catalyst was better than that NiMoS/γ-Al2O3 catalyst. the NiMoS/γ-Al2O3 catalyst exhibits higher DDS selectivity (3.0) than NiMo/γ-Al2O3 catalyst (2.55).

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23

Chein, Rei-Yu, and Chih-Chang Wang. "Experimental Study on CO2 Methanation over Ni/Al2O3, Ru/Al2O3, and Ru-Ni/Al2O3 Catalysts." Catalysts 10, no. 10 (September 25, 2020): 1112. http://dx.doi.org/10.3390/catal10101112.

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CO2 methanation is recognized as one of the best technologies for storing intermittent renewable energy in the form of CH4. In this study, CO2 methanation performance is investigated using Ni/Al2O3, Ru/Al2O3, and Ru-Ni/Al2O3 as the catalysts under conditions of atmospheric pressure, a molar ratio of H2/CO2 = 5, and a space velocity of 5835 h−1. For reaction temperatures ranging from 250 to 550 °C, it was found that the optimum reaction temperature is 400 °C for all catalysts studied. At this temperature, the maximum values of CO2 conversion, H2 efficiency, and CH4 yield and lowest CO yield can be obtained. With temperatures higher than 400 °C, reverse CO2 methanation results in CO2 conversion and CH4 yield decreases with increased temperature, while CO is formed due to reverse water-gas shift reaction. The experimental results showed that CO2 methanation performance at low temperatures can be enhanced greatly using the bimetallic Ru-Ni catalyst compared with the monometallic Ru or Ni catalyst. Under ascending-descending temperature changes between 250 °C and 550 °C, good thermal stability is obtained from Ru-Ni/Al2O3 catalyst. About a 3% decrease in CO2 conversion is found after three continuous cycles (74 h) test.

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Melnikov, Dmitry, Valentine Stytsenko, Elena Saveleva, Mikhail Kotelev, Valentina Lyubimenko, Evgenii Ivanov, Aleksandr Glotov, and Vladimir Vinokurov. "Selective Hydrogenation of Acetylene over Pd-Mn/Al2O3 Catalysts." Catalysts 10, no. 6 (June 4, 2020): 624. http://dx.doi.org/10.3390/catal10060624.

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Novel bimetallic Pd-Mn/Al2O3 catalysts are designed by the decomposition of cyclopentadienylmanganese tricarbonyl (cymantrene) on reduced Pd/Al2O3 in an H2 atmosphere. The peculiarities of cymantrene decomposition on palladium and, thus, the formation of bimetallic Pd-Mn catalysts are studied. The catalysts are characterized by N2 adsorption, H2 pulse chemisorption, temperature-programmed desorption of hydrogen (TPD-H2), transmission electron microscopy (TEM), energy-dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), and diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS). The modified catalysts show the changed hydrogen chemisorption properties and the absence of weakly bonded hydrogen. Using an organomanganese precursor provides an uniform Mn distribution on the catalyst surface. Tested in hydrogenation of acetylene, the catalysts show both higher activity and selectivity to ethylene (20% higher) compared to the non-modified Pd/Al2O3 catalyst. The influence of the addition of Mn and temperature treatment on catalyst performance is studied. The optimal Mn content and treatment temperature are found. It is established that modification with Mn changes the route of acetylene hydrogenation from a consecutive scheme for Pd/Al2O3 to parallel one for the Pd-Mn samples. The reaction rate shows zero overall order by reagents for all tested catalysts.

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25

Wang, Guangjian, Ning Song, Kai Lu, Wentai Wang, Liancheng Bing, Qinqin Zhang, Haitao Fu, Fang Wang, and Dezhi Han. "Ca-Doped CrOX/γ-Al2O3 Catalysts with Improved Dehydrogenation Performance for the Conversion of Isobutane to Isobutene." Catalysts 9, no. 11 (November 16, 2019): 968. http://dx.doi.org/10.3390/catal9110968.

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The dehydrogenation of low-carbon alkane to obtain olefins is an effective way to meet the steadily increasing demand of these building blocks in chemical industry. In this study, Ca-doped CrOx/γ-Al2O3 catalysts were fabricated via a one-pot method by employing Cr(OH)3 as the precursor, and their catalytic performances were tested in the dehydrogenation of isobutane to isobutene (DITI) process. The prepared catalysts were intensively characterized by XRD, SEM, NH3-TPD, H2-TPR, low-temperature N2 adsorption–desorption, etc. These characterization results indicated that the doping of Ca into the CrOx/γ-Al2O3 catalysts could tune the acidity properties of the prepared catalysts and enhance the interaction between the active species and support. The Ca-doped CrOx/γ-Al2O3 catalysts, especially the Ca2-Cr/γ-Al2O3 catalyst with a Ca doping of 2 wt%, exhibited a superior catalytic performance in the DITI process in comparison with the undoped catalyst.

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26

Alayat, Abdulbaset, Elena Echeverria, Farid Sotoudehniakarani, David N. Mcllroy, and Armando G. McDonald. "Alumina Coated Silica Nanosprings (NS) Support Based Cobalt Catalysts for Liquid Hydrocarbon Fuel Production From Syngas." Materials 12, no. 11 (June 4, 2019): 1810. http://dx.doi.org/10.3390/ma12111810.

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The effects of Al2O3 coating on the performance of silica nanospring (NS) supported Co catalysts for Fischer–Tropsch synthesis (FTS) were evaluated in a quartz fixed-bed microreactor. The Co/NS-Al2O3 catalysts were synthesized by coating the Co/NS and NS with Al2O3 by an alkoxide-based sol-gel method (NS-Al-A and NS-Al-B, respectively) and then by decorating them with Co. Co deposition was via an impregnation method. Catalysts were characterized before the FTS reaction by the Brunauer–Emmett–Teller (BET) method, X-ray diffraction, transmission electron microscopy, temperature programmed reduction, X-ray photoelectron spectroscopy, differential thermal analysis and thermogravimetric analysis in order to find correlations between physico-chemical properties of catalysts and catalytic performance. The products of the FTS were trapped and analyzed by GC-TCD and GC-MS to determine the CO conversion and reaction selectivity. The Al2O3 coated NS catalyst had a significant affect in FTS activity and selectivity in both Co/NS-Al2O3 catalysts. A high CO conversion (82.4%) and Σ > C6 (86.3%) yield were obtained on the Co/NS-Al-B catalyst, whereas the CO conversion was 62.8% and Σ > C6 was 58.5% on the Co/NS-Al-A catalyst under the same FTS experimental condition. The Co/NS-Al-A catalyst yielded the aromatic selectivity of 10.2% and oxygenated compounds.

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27

González-Castaño, Miriam, Estelle le Saché, Cameron Berry, Laura Pastor-Pérez, Harvey Arellano-García, Qiang Wang, and Tomás Reina. "Nickel Phosphide Catalysts as Efficient Systems for CO2 Upgrading via Dry Reforming of Methane." Catalysts 11, no. 4 (March 30, 2021): 446. http://dx.doi.org/10.3390/catal11040446.

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This work establishes the primordial role played by the support’s nature when aimed at the constitution of Ni2P active phases for supported catalysts. Thus, carbon dioxide reforming of methane was studied over three novel Ni2P catalysts supported on Al2O3, CeO2 and SiO2-Al2O3 oxides. The catalytic performance, shown by the catalysts’ series, decreased according to the sequence: Ni2P/Al2O3 > Ni2P/CeO2 > Ni2P/SiO2-Al2O3. The depleted CO2 conversion rates discerned for the Ni2P/SiO2-Al2O3 sample were associated to the high sintering rates, large amounts of coke deposits and lower fractions of Ni2P constituted in the catalyst surface. The strong deactivation issues found for the Ni2P/CeO2 catalyst, which also exhibited small amounts of Ni2P species, were majorly associated to Ni oxidation issues. Along with lower surface areas, oxidation reactions might also affect the catalytic behaviour exhibited by the Ni2P/CeO2 sample. With the highest conversion rate and optimal stabilities, the excellent performance depicted by the Ni2P/Al2O3 catalyst was mostly related to the noticeable larger fractions of Ni2P species established.

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Marinkovic, Milos, Nikola Stojkovic, Marija Vasic, Radomir Ljupkovic, Sofija Rancic, Boban Spalovic, and Aleksandra Zarubica. "Synthesis of biodiesel from sunflower oil over potassium loaded alumina as heterogeneous catalyst: The effect of process parameters." Chemical Industry 70, no. 6 (2016): 639–48. http://dx.doi.org/10.2298/hemind150807001m.

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Heterogeneous catalysis is in recent focus of research for biodiesel production from vegetable oils because of advantages such as easy separation and reuse of catalysts, although homogeneous catalysis is most commonly used method. The aim of this study was preparation of ?-Al2O3 support by modified sol-gel procedure, synthesis of the KI/Al2O3 catalyst and testing its activity in the transesterification of sunflower oil with methanol. Influences of different process parameters on conversion of sunflower oil to methyl esters were examined. The gained results implicate that the potassium iodide incorporation into/onto the structure of ?-Al2O3 significantly influences textural and structural properties of the catalyst. Additionally, the catalyst basic strength is increased and all together those properties are positively affecting the activity of the catalyst in the reaction of transesterification of sunflower oil with methanol. The impregnation of alumina with potassium iodide resulted in the additional formation of basic catalytically active sites. The surface properties of the catalyst have an essential impact on its catalytic performance. Under relatively mild process conditions and relatively short reaction time, the usage of the KI/Al2O3 catalyst resulted in very high conversion to fatty acids methyl esters (i.e. 99.99 %).

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29

Yu, Yunwu, Lianjie Liang, Yunxue Liu, Changwei Xu, Qing Wang, Wanyang Niu, and Changwei Liu. "Ni2P/Al2O3 hydrodesulfurization catalysts prepared from hypophosphite under a nitrogen atmosphere." Progress in Reaction Kinetics and Mechanism 45 (October 3, 2019): 146867831987764. http://dx.doi.org/10.1177/1468678319877643.

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A novel method for preparing Ni2P/Al2O3(L) catalysts in an N2 atmosphere by decomposition of hypophosphites was proposed, and Ni2P/Al2O3(T) catalyst was synthesized by the temperature programmed reduction method in a H2 atmosphere for comparison. These prepared catalysts were washed with deionized water to remove impurities. The X-ray diffraction, N2-adsorption specific surface area measurements, CO uptake, and X-ray photoelectron spectroscopy were applied to characterize these catalysts. The activities of the Ni2P/Al2O3 catalysts prepared with the two different methods were tested in the dibenzothiophene hydrodesulfurization reaction.

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30

Mohd Zabidi, Noor Asmawati, Tuan Syahylah Tuan Sulong, and Sardar Ali. "Synthesis and Characterization of Cu/ZnO Catalyst on Carbon Nanotubes and Al₂O₃ Supports." Materials Science Forum 916 (March 2018): 139–43. http://dx.doi.org/10.4028/www.scientific.net/msf.916.139.

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CO2 conversion into valuable chemicals is an attractive option to deal with the increasing CO2 concentration in the atmosphere. In this study, Cu/ZnO catalyst was synthesized on multi-walled carbon nanotubes (MWCNTs) and Al2O3 supports via incipient wetness impregnation method. The physicochemical properties of the catalysts were investigated using TEM, XRD, N2 adsorption-desorption analysis, H2-TPR and XPS. The performance of the synthesized catalysts in a CO2 hydrogenation reaction was evaluated in a fixed-bed reactor at 503 K, 22.5 bar and H2:CO2 ratio of 3:1. TEM images showed that Cu/ZnO nanoparticles were deposited inside the CNTs as well as on the exterior walls of the CNTs. The average CuO crystallite size on Al2O3 and CNTs supports was 15.7 and 11 nm, repectively. Results of H2-TPR studies showed that the reducibility of the catalyst was improved on the CNTs support. XPS analysis confirmed the presence of Cu2+ in the samples, however, the binding energy of Cu 2p3/2 peak on the Al2O3 support was shifted to higher value compared to that of CNTs support. Products obtained from the CO2 hydrogenation reaction in the presence of these catalyts were methanol, ethanol, methyl formate and methane. The CO2 conversion of around 23% was obtained using both types of catalysts, however, Cu/ZnO on CNTs resulted in higher yield of methyl formate compared to that of Al2O3-supported catalyst.

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Nuzhdin, Alexey, Galina Bukhtiyarova, Aleksander Porsin, Igor Prosvirin, Irina Deliy, Vladimir Volodin, Evgeny Gerasimov, Evgeniya Vlasova, and Valerii Bukhtiyarov. "Effect of Mono-, Di-, and Triethylene Glycol on the Activity of Phosphate-Doped NiMo/Al2O3 Hydrotreating Catalysts." Catalysts 9, no. 1 (January 17, 2019): 96. http://dx.doi.org/10.3390/catal9010096.

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The effect of glycols on the catalytic properties of phosphate-doped NiMo/Al2O3 catalysts in the hydrotreating of straight-run gas oil (SRGO) was studied. The NiMo(P)/Al2O3 catalysts were prepared using ethylene glycol (EG), diethylene glycol (DEG), and triethylene glycol (TEG) as additives. The organic agent was introduced into the aqueous impregnation solution obtained by the dissolving of MoO3 in H3PO4 solution, followed by Ni(OH)2 addition. The Raman and UV–Vis studies show that the impregnation solution contains diphosphopentamolybdate HxP2Mo5O23(6−x)− and Ni(H2O)62+, and that these ions are not affected by the presence of glycols. When the impregnation solution comes in contact with the γ-Al2O3 surface, HxP2Mo5O23(6−x)− is decomposed completely. The catalysts were characterized by Raman spectroscopy, low-temperature N2 adsorption, X-ray photoelectron spectroscopy, and transmission electron microscopy. It is shown that the sulfide catalysts prepared with glycols display higher activity in the hydrotreating of straight-run gas oil than the NiMoP/Al2O3 catalyst prepared without the additive. The hydrodesulfurization and hydrodenitrogenation activities depend on the glycol type and are decreased in the following order: NiMoP-DEG/Al2O3 > NiMoP-EG/Al2O3 > NiMoP-TEG/Al2O3 > NiMoP/Al2O3. The higher activity of NiMoP-DEG/Al2O3 can be explained with the higher dispersion of molybdenum on the surface of the catalyst in the sulfide state.

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Zhu, Tianhan, Hua Song, Feng Li, and Yanguang Chen. "Hydrodeoxygenation of Benzofuran over Bimetallic Ni-Cu/γ-Al2O3 Catalysts." Catalysts 10, no. 3 (March 1, 2020): 274. http://dx.doi.org/10.3390/catal10030274.

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Bimetallic NixCu(10−x)/γ-Al2O3 catalysts (where x is the mass fraction of Ni) with different Ni/Cu mass ratios were prepared. The catalysts were characterized by X-ray diffractometry, N2 adsorption–desorption, inductively coupled plasma mass spectrometry, X-ray photoelectron spectroscopy, H2-temperature programmed reduction, and transmission electron microscopy. The effect of Ni/Cu mass ratio on benzofuran hydrodeoxygenation was investigated in a fixed-flow reactor. Cu addition improved the NiO reducibility. The strong interaction of Ni and Cu led to the formation of smaller and highly dispersed CuO and NiO species over γ-Al2O3, which favors an improvement in catalytic activity. Among the as-prepared catalysts, the Ni5Cu5/γ-Al2O3 showed the highest deoxygenated product yield (79.9%) with an acceptable benzofuran conversion of 95.2%, which increased by 18.3% and 16.9% compared with that of the monometallic Ni/γ-Al2O3 catalyst. A possible reaction network was proposed, which would provide insight into benzofuran hydrodeoxygenation over the Ni5Cu5/γ-Al2O3 catalyst.

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Vacharapong, Pumiwat, Sirintra Arayawate, Sasimas Katanyutanon, Pisanu Toochinda, Luckhana Lawtrakul, and Sumittra Charojrochkul. "Enhancement of Ni Catalyst Using CeO2–Al2O3 Support Prepared with Magnetic Inducement for ESR." Catalysts 10, no. 11 (November 21, 2020): 1357. http://dx.doi.org/10.3390/catal10111357.

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The effect of magnetic inducement in support preparation was studied to reduce coke and improve the activity of Ni catalysts for ethanol steam reforming (ESR) at 550–650 °C. Magnetic inducement was introduced to prepare 5 mol % CeO2 in Al2O3 support in order to control the composition and the distribution of Ce in Al2O3. The results show that using CeO2–Al2O3 support with magnetic inducement affects both hydrogen production and coke reduction, where Ni/CeO2–Al2O3 support prepared under magnetic inducement with N–N pole arrangement (Ni/CeO2–Al2O3 (N–N)) exhibited the highest hydrogen production and the lowest coke formation among the catalysts used in this work. Compared with Ni/CeO2–Al2O3 (no magnet), Ni/CeO2–Al2O3 (N–N) catalysts yield 14.0% higher H2 production and 31.7% less coke production. The modified catalyst preparation process used in this study could create catalysts for hydrogen production from ESR which are high in performance and stability but low in preparation cost.

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Wang, Hanhan, Tingting Lu, Yuna Li, Bo Wu, Jianwei Xue, Fuxiang Li, and Zhiping Lv. "Study on Low-Temperature Catalytic Dehydrogenation Reaction of Tail Chlorine by Pd/Al2O3." Journal of Chemistry 2016 (2016): 1–6. http://dx.doi.org/10.1155/2016/5620316.

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The catalytic dehydrogenation reaction of tail chlorine by Pd was studied using a fixed-bed reactor at low temperature from 30 to 100°C. Different catalyst supports such as SiO2 and Al2O3 were applied to prepare Pd catalysts by the incipient-wetness impregnation method. And the catalysts were characterized by XRD, FTIR, XPS, SEM, and N2 adsorption-desorption. The catalyst Pd loading on both SiO2 and Al2O3 had a catalytic effect on the dehydrogenation reaction, but the carrier Al2O3 was more superior. The hydrogen conversion and selectivity of hydrogen-oxygen reaction increased first and then decreased with Pd loading amount and temperature by using Pd/Al2O3 as catalysts, but the influence of temperature was limited when it was higher than 60°C. The hydrogen conversion was 97.38% and selectivity of hydrogen-oxygen reaction was 79% when the reaction temperature was at 60°C with 1 wt.% Pd/Al2O3.

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35

Park, Kilsu, Gisung Bae, and Taegyu Kim. "An In-Situ Transmission Fourier Transform Infrared Study on the Interaction Mechanism of Plasma with Nano-Catalyst for CO2 Methanation." Journal of Nanoscience and Nanotechnology 21, no. 7 (July 1, 2021): 3858–62. http://dx.doi.org/10.1166/jnn.2021.19187.

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The effects of discharge conditions and catalysts on CO2 methanation under the plasma were investigated via In-Situ transmission FTIR and OES analysis. The bare Al2O3, Ni/Al2O3 and Ru/Al2O3 catalysts were coated on the ZnSe window using the modified sol–gel method for In-Situ transmission FTIR analysis. It was confirmed from the OES analysis that the intensity of excited hydrogen increased in all catalysts as the discharge frequency and voltage increased, and the increment of H+ peak intensity was the largest in the Ru/Al2O3 catalyst. In addition, it was found from the In-Situ transmission FTIR analysis that the O-H band was all disappeared as the frequency and voltage increased. In conclusion, the increased H+ with the decomposition of O–H led to the increase in the CH4 conversion, resulting in the highest CH4 conversion in the Ru/Al2O3 catalyst.

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Cheng, Hong Wei, Xiong Gang Lu, and Wei Zhong Ding. "Steam Reforming of Simulated Coke Oven Gas over Ni/Al₂O₃-MgO Catalysts for Syngas Production." Advanced Materials Research 152-153 (October 2010): 817–20. http://dx.doi.org/10.4028/www.scientific.net/amr.152-153.817.

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The steam reforming of simulated coke oven gas (COG) with toluene as a model tar compound for syngas production was investigated over Ni/Al2O3-MgO catalysts. XRD results showed that the catalysts with high calcination temperature and Al2O3 content after calcination formed (Ni,Mg)Al2O4 spinel and Ni-Mg-O solid solution structure. At optimized reaction conditions, toluene and CH4 can be completely converted, while a H2 yield of 71.8% and a CO yield of 76.1% have been achieved at 800 oC. The catalysts with appropriate calcination temperature and Al2O3 content showed better catalytic activity and resistance to coking, which will be promising catalysts in the catalytic reforming of COG.

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37

Halawy, Samih A., Mohamed A. Mohamed, and Suzan F. Abd El-Hafez. "The Poisoning Effect of Co3O4 on γ-Al2O3 and MgO Supports During the Decomposition of Isopropyl Alcohol." Collection of Czechoslovak Chemical Communications 60, no. 12 (1995): 2057–63. http://dx.doi.org/10.1135/cccc19952057.

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Catalysts containing 20 wt.% Co3O4 supported on γ-Al2O3 and MgO were prepared. The catalyst precursors were analyzed by TG, DTG and DTA, and the calcined catalysts (400-700 °C) were characterized by XRD. The amount of excess surface oxygen for the catalysts was estimated iodometrically. The vapour-phase decomposition of isopropyl alcohol over these catalysts was studied. Co3O4/γ-Al2O3 catalysts are selective towards propene formation, whereas Co3O4/MgO catalysts are selective towards acetone formation. The poisoning effect of Co3O4 on both supports and the activity of the catalysts is discussed.

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38

Le, Thien An, Jong Kyu Kang, Sae Ha Lee, and Eun Duck Park. "CO and CO2 Methanation Over Ni/γ-Al2O3 Prepared by Deposition-Precipitation Method." Journal of Nanoscience and Nanotechnology 19, no. 6 (June 1, 2019): 3252–62. http://dx.doi.org/10.1166/jnn.2019.16585.

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Various Ni catalysts supported on γ-Al2O3 were prepared by a wet impregnation (WI) method and deposition-precipitation (DP) method with different precipitants and applied to CO and CO2 methanation. The prepared catalysts were characterized by various techniques including nitrogen physisorption, X-ray diffraction (XRD), temperature-programmed reduction with H2 (H2-TPR), H2 chemisorption, transmission electron microscopy (TEM), thermogravimetric analysis (TGA), and inductively coupled plasma-atomic emission spectroscopy (ICP-AES). Irrespective of kinds of precipitant, the Ni/γ-Al2O3 catalysts prepared with a DP method showed a remarkable enhanced catalytic performance in CO and CO2 methanation compared with the Ni/γ-Al2O3 catalyst prepared with a WI method owing to the higher catalytic active surface area (CASA). In the case of Ni/γ-Al2O3 catalysts prepared with a DP method, the high calcination temperatures are not favorable for the high catalytic activity due to the decreased reduction degree of Ni oxide species and CASA. The reduction degree of Ni oxide species can be increased with reduction temperature. However, the higher reduction temperature above 500 °C is not desirable to achieve the high catalytic activity because of the decreased CASA. The selective CO methanation was also accomplished at lower temperatures over the Ni/γ-Al2O3 catalyst prepared with a DP method than over the Ni/γ-Al2O3 catalyst prepared with a WI method.

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Kucharczyk, Barbara, Bogdan Szczygieł, and Jacek Chęcmanowski. "The effect of catalyst precursors and conditions of preparing Pt and Pd-Pt catalysts on their activity in the oxidation of hexane." Open Chemistry 15, no. 1 (July 26, 2017): 182–88. http://dx.doi.org/10.1515/chem-2017-0020.

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AbstractThe effectiveness of under-air n-hexane oxidation over monolithic catalysts made of heat-resistant foil, containing Pt, Pd or Pt-Pd, was compared. Pt and Pd precursors, either containing chlorine or devoid of chlorine, were used to prepare the catalysts. The chlorine- containing Pt (H2PtCl6) and Pd (PdCl2) precursors were found to lower the activity of the catalysts in hexane oxidation. Studies of the effect of 0.15% Pt/Al2O3 catalyst (using H2PtCl6 as the precursor) calcination conditions on catalyst activity showed the catalyst calcined in static air at 500°C to be the most active. Airflow calcination of the catalyst does not change its catalytic properties. In comparison with the 0.5% Pd/Al2O3 catalyst obtained from Pd(NO3)2, the use of a bimetallic 0.5% Pd/0.1% Pt/Al2O3 catalyst, in which the precursors were Pd(NO3)2 and Pt(NO3)4, resulted in the lowering of 10% and 50% n-hexane temperature by 15°C and 10°C.

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Ma, Yuyao, Yuxia Ma, Min Liu, Yang Chen, Xun Hu, Zhengmao Ye, and Dehua Dong. "Study on Nanofibrous Catalysts Prepared by Electrospinning for Methane Partial Oxidation." Catalysts 9, no. 5 (May 23, 2019): 479. http://dx.doi.org/10.3390/catal9050479.

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Electrospinning is a simple and efficient technique for fabricating fibrous catalysts. The effects of preparation parameters on catalyst performance were investigated on fibrous Ni/Al2O3 catalysts. The catalyst prepared with H2O/C2H5OH solvent showed higher catalytic activity than that with DMF/C2H5OH solvent because of the presence of NiO in the catalyst prepared with DMF/C2H5OH solvent. The metal ion content of the precursor also influences catalyst properties. In this work, the Ni/Al2O3 catalyst prepared with a solution containing the metal ion content of 30 wt % demonstrated the highest Ni dispersion and therefore the highest catalytic performance. Additionally, the Ni dispersion decreased as calcination temperature was enhanced from 700 to 900 °C due to the increased Ni particle sizes, which also caused a high reduction temperature and low catalytic activity in methane partial oxidation. Finally, the fibrous Ni/Al2O3 catalysts can achieve high syngas yields at high reaction temperatures and high gas flow rates.

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de Albuquerque Fragoso, Danielle Munick, Henrique Fonseca Goulart, Antonio Euzebio Goulart Santana, and Samuel David Jackson. "Targeted Substituted-Phenol Production by Strategic Hydrogenolysis of Sugar-Cane Lignin." Biomass 1, no. 1 (June 18, 2021): 11–28. http://dx.doi.org/10.3390/biomass1010002.

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In this work, a waste-derived lignin with abundant uncondensed linkages, using accessible solvents (acetone/water mixture) and low-cost catalysts showed successful depolymerization for the production of target molecules 4-ethylphenol, 4-propyl-2,6-dimethoxyphenol and 4-propyl-2-methoxyphenol. Lignin samples were obtained from sugar-cane bagasse residue by an organosolv process. Four alumina-based catalysts (Pt/Al2O3, Rh/Al2O3, Ni/Al2O3 and Fe/Al2O3) were used to depolymerize the sugar cane lignin (SCL) in an acetone/water mixture 50/50 v/v at 573 K and 20 barg hydrogen. This strategic depolymerisation-hydrogenolysis process resulted in the molecular weight of the SCL being reduced by half while the polydispersity also decreased. Catalysts significantly improved product yield compared to thermolysis. Specific metals directed product distribution and yield, Rh/Al2O3 gave the highest overall yield (13%), but Ni/Al2O3 showed the highest selectivity to a given product (~32% to 4-ethylphenol). Mechanistic routes were proposed either from lignin fragments or from the main polymer. Catalysts showed evidence of carbon laydown that was specific to the lignin rather than the catalyst. These results showed that control over selectivity could be achievable by appropriate combination of catalyst, lignin and solvent mixture.

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Doukeh, Rami, Ancuta Trifoi, Mihaela Bombos, Ionut Banu, Minodora Pasare, and Ion Bolocan. "Hydrodesulphurization of Thiophene over Co, Mo and CoMo /g-Al2O3 Catalysts." Revista de Chimie 69, no. 2 (March 15, 2018): 396–99. http://dx.doi.org/10.37358/rc.18.2.6114.

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The hydrodesulphurization (HDS) of thiophene was performed on monometallic catalysts Co/g -Al2O3, Mo/g -Al2O3 and bimetallic CoMo/g -Al2O3. Experiments were carried out on a fixed bed catalytic reactor at 175-300�C, 30-60 atm, thiophene volume hourly space velocities of 1h-1- 4h-1 and molar ratio hydrogen/thiophene of 60/1. The thiophene conversion on the bimetallic CoMo/g -Al2O3 catalyst was higher than on Co/g -Al2O3 or Mo/g -Al2O3.

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Li, Feng, Hua Song, and Hua Yang Zhang. "Preparation and Ultra-Deep Hydrorefining Performance of Ni-P/Al₂O₃-ZrO₂ Catalysts." Advanced Materials Research 236-238 (May 2011): 724–27. http://dx.doi.org/10.4028/www.scientific.net/amr.236-238.724.

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A series of Al2O3-ZrO2 (AZ-X) composite oxides with different ZrO2 contents were prepared by a chemical precipitation method. Ni-P/AZ-X catalysts were prepared by temperature-programmed reduction. The supports and catalysts were extensively characterized by X-ray diffraction (XRD) and BET. The effects of support composition and P/Ni molar ratios on the catalytic performance of the catalysts were investigated by thiophene hydrodesulfurization (HDS) and pyridine hydrodenitrogenation (HDN). In comparison with Al2O3, Al2O3-ZrO2 (20 wt% ZrO2) composite oxide supported Ni-P catalyst exhibited higher activity and the activities of HDS and HDN increased by 7.5 % and 11.1 %, respectively. Studies of Ni-P/AZ-X catalysts with varying initial P/Ni molar ratios indicated that oxidic precursors with molar ratios of P/Ni = 2/1 yielded catalyst containing phase-pure Ni2P which exhibited optimal activity.

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Suryanto, Andi, Ummu Kalsum, Lailatul Qadariya, and Mahfud Mahfud. "Production of Methyl ester from Coconut Oil using Heterogeneous K/Al2O3 under Microwave Irradiation." Journal of Chemical Process Engineering 5, no. 2 (December 20, 2020): 23–29. http://dx.doi.org/10.33536/jcpe.v5i2.754.

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Methyl esters derived from coconut oil are very interesting to study because they contain free fatty acids with a medium carbon chain structure (C12-C14), so most methyl esters (70%) can be bio-kerosene and the rest can be biodiesel. The process of preparing methyl ester by reaction of Trans-esterification triglyceride generally using a homogeneous KOH catalyst but this process requires a long catalyst separation process through washing and drying process. The use of heterogeneous catalysts in the production of methyl esters can remove the washing and drying processes, but trans-esterification reactions with heterogeneous catalysts require severe conditions (high pressure and high temperature), whereas at low temperatures and atmospheric conditions, the methyl ester yield is relatively low. Using microwave-irradiated trans-esterification reactions with heterogeneous catalysts, it is expected to be much faster and can obtained higher yields. Therefore, in this study we prepare a heterogeneous catalyst K/Al2O3 using solution KOH that impregnated in catalyst support Al2O3, and catalyst obtained are caracterized by XRD, BET dan SEM. Our objective was to compare the yield of methyl esters obtained through the trans-esterification process of coconut oil assisted by microwave using a heterogeneous K / Al2O3 catalyst with yield obtained using a homogeneous KOH catalyst. Experimental equipment consists of a batch reactor placed in a microwave oven equipped with a condenser, agitator and temperature controller. The batch process was carried out at atmospheric pressure with variation of K/Al2O3 catalyst concentration (0.5, 1.0, 1.5, 2.0, 2.5%) and microwave power (100, 264 and 400 W). In general, the process of producing methyl esters by heterogeneous catalysts will get three layers, wherein the first layer is the product of methyl ester, the second layer is glycerol and the third layer is the catalyst. The experimental results show that the methyl ester yield increases with increasing of microwave power, catalyst concentration and reaction time. The results obtained with K /Al2O3 catalysts are generally slightly lower than those obtained using a homogeneous KOH catalyst. However, the yield of methyl esters obtained by the K / Al2O3 heterogeneous catalyst process are relatively easy to separate rather than using a homogeneous KOH catalyst.

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Litvyakova, Natalya, Tatiana Bugrova, and Grigory Mamontov. "Al₂O₃/SiO₂ Materials with Bimodal Pore Size Distribution as Support for Heterogeneous Catalysts." Advanced Materials Research 1085 (February 2015): 79–83. http://dx.doi.org/10.4028/www.scientific.net/amr.1085.79.

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The Al2O3/SiO2 materials prepared by impregnation of mesoporous silica with water solution of Al(NO3)3·9H2O were suggested to be used as supports for catalyst of high-temperature catalytic reactions. It was shown that the distribution of Al2O3 component inside wide pores of silica (10-50 nm) occurs with the formation of Al2O3 layer in case of low loading and porous layer or particles, if Al2O3 loading increases. Thus, materials with bimodal pore size distribution were obtained. The Cr-containing catalysts were prepared on the basis of these supports and tested in the process of isobutane dehydrogenation at 540 °C. It was observed that the activity of the obtained Cr/Al2O3/SiO2 materials was comparable with the one for Cr/Al2O3 catalyst. Thus, the suggested Al2O3/SiO2 materials with unique porous structure are promising to be used as supports for catalysts for high-temperature reactions.

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Liu, Xiaozhan, Lu Zhao, Ying Li, Kegong Fang, and Minghong Wu. "Ni-Mo Sulfide Semiconductor Catalyst with High Catalytic Activity for One-Step Conversion of CO2 and H2S to Syngas in Non-Thermal Plasma." Catalysts 9, no. 6 (June 12, 2019): 525. http://dx.doi.org/10.3390/catal9060525.

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Carbon dioxide (CO2) and hydrogen sulfide (H2S) ordinarily coexist in many industries, being considered as harmful waste gases. Simultaneously converting CO2 and H2S into syngas (a mixture of CO and H2) will be a promising economic strategy for enhancing their recycling value. Herein, a novel one-step conversion of CO2 and H2S to syngas induced by non-thermal plasma with the aid of Ni-Mo sulfide/Al2O3 catalyst under ambient conditions was designed. The as-synthesized catalysts were characterized by using XRD, nitrogen sorption, UV-vis, TEM, SEM, ICP, and XPS techniques. Ni-Mo sulfide/Al2O3 catalysts with various Ni/Mo molar ratios possessed significantly improved catalytic performances, compared to the single-component catalysts. Based on the modifications of the physical and chemical properties of the Ni-Mo sulfide/Al2O3 catalysts, the variations in catalytic activity are carefully discussed. In particular, among all the catalysts, the 5Ni-3Mo/Al2O3 catalyst exhibited the best catalytic behavior with high CO2 and H2S conversion at reasonably low-energy input in non-thermal plasma. This method provides an alternative route for syngas production with added environmental and economic benefits.

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Abasaeed, Ahmed, Samsudeen Kasim, Wasim Khan, Mahmud Sofiu, Ahmed Ibrahim, Anis Fakeeha, and Ahmed Al-Fatesh. "Hydrogen Yield from CO2 Reforming of Methane: Impact of La2O3 Doping on Supported Ni Catalysts." Energies 14, no. 9 (April 23, 2021): 2412. http://dx.doi.org/10.3390/en14092412.

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Development of a transition metal based catalyst aiming at concomitant high activity and stability attributed to distinguished catalytic characteristics is considered as the bottleneck for dry reforming of methane (DRM). This work highlights the role of modifying zirconia (ZrO2) and alumina (Al2O3) supported nickel based catalysts using lanthanum oxide (La2O3) varying from 0 to 20 wt% during dry reforming of methane. The mesoporous catalysts with improved BET surface areas, improved dispersion, relatively lower reduction temperatures and enhanced surface basicity are identified after La2O3 doping. These factors have influenced the catalytic activity and higher hydrogen yields are found for La2O3 modified catalysts as compared to base catalysts (5 wt% Ni-ZrO2 and 5 wt% Ni-Al2O3). Post-reaction characterizations such as TGA have showed less coke formation over La2O3 modified samples. Raman spectra indicates decreased graphitization for La2O3 catalysts. The 5Ni-10La2O3-ZrO2 catalyst produced 80% hydrogen yields, 25% more than that of 5Ni-ZrO2. 5Ni-15La2O3-Al2O3 gave 84% hydrogen yields, 8% higher than that of 5Ni-Al2O3. Higher CO2 activity improved the surface carbon oxidation rate. From the study, the extent of La2O3 loading is dependent on the type of oxide support.

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Yergaziyeva, G. Y., S. Tayrabekova, M. Mambetova, S. Ozganbayeva, and S. Smagulova. "Conversion of bioethanol over oxide catalysts." Горение и Плазмохимия 17, no. 1 (January 5, 2019): 40–46. http://dx.doi.org/10.18321/cpc281.

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The conversion of bioethanol over supported oxide catalysts (CuO, ZnO, Cr2O3,CeO2) was studied, among which the most active in the production of hydrogenis 3% CuO / γ-Al2O3. Modification of 3% CuO / γ-Al2O3 catalyst with Cr2O3, ZnOand CeO2 promotes the growth of hydrogen yield. The highest concentrationof hydrogen at 300° C and a space velocity of 1 h-1 on CuO-ZnO / γ-Al2O3 was48% by volume. The acidity of catalysts for adsorption-desorption of pyridine byinfrared spectroscopy (ITI Matson FTIR) was determined. When the content ofCuO in the catalyst is increased from 1 to 3%, the amount of Lewis acidic centers(LAS) increases from 58 to 82 µmol/ gcat. Modification with chromium oxide ofthe copper catalyst increases the number of LAS from 82 to 156 µmol/ gcat byadsorption of pyridine at 150° C and from 79 to 120 µmol/ gcat with pyridineadsorption at 250° C. It has been established that an increase in the number ofLewis acid sites has a positive effect on the yield of hydrogen in the conversion ofbioethanol. According to electron microscopy, the modification of catalysts leadsto an increase in the dispersity of the catalyst and to a uniform distribution ofparticles on the surface of the catalyst, which also contributes to its greater activityin the production of hydrogen.

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Yadav, Deepak, Ashish R. Kavaiya, Devendra Mohan, and Ram Prasad. "Low Temperature Selective Catalytic Reduction (SCR) of NOx Emissions by Mn-doped Cu/Al2O3 Catalysts." Bulletin of Chemical Reaction Engineering & Catalysis 12, no. 3 (October 28, 2017): 415. http://dx.doi.org/10.9767/bcrec.12.3.895.415-429.

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The 15 mol% Cu/Al2O3 catalysts with different Mn doping (0.5, 1.0, 1.5, mol%) were prepared using PEG-300 surfactant following evaporation-induced self-assembly (EISA) method. Calcination of precursors were performed in flowing air conditions at 500 ºC. The catalysts were characterized by X-ray Diffraction (XRD), X-ray Photoelectron Spectroscopy (XPS), Scanning Electron Microscope Energy Dispersive X-Ray (SEM-EDX), Fourier Transform Infra Red (FTIR), and N2 physisorption. The catalysts activities were evaluated for H2 assisted LPG-SCR of NO in a packed bed tubular flow reactor with 200 mg catalyst under the following conditions: 500 ppm NO, 8 % O2, 1000 ppm LPG, 1 % H2 in Ar with total flow rate of 100 mL/min. Characterization of the catalysts revealed that surface area of 45.6-50.3 m2/g, narrow pore size distribution (1-2 nm), nano-size crystallites, Cu2+ and Mn2+ phases were principal active components. Hydrogen enhanced significantly selective reduction of NO to N2 with LPG over 1.0 mol % Mn-Cu/Al2O3 giving 95.56 % NO reduction at 150 ºC. It was proposed that the synergistic interaction between H2 and LPG substantially widened the NO reduction temperature window and a considerable increase in both activity and selectivity. Negligible loss of catalyst activity was observed for the 50 h of stream on run experiment at 150 ºC. The narrow pore size distribution, thermal stability of the catalyst and optimum Mn doping ensures good dispersion of Cu and Mn over Al2O3 that improved NO reduction in H2-LPG SCR system. Copyright © 2017 BCREC Group. All rights reservedReceived: 5th January 2017; Revised: 20th May 2017; Accepted: 20th May 2017; Available online: 27th October 2017; Published regularly: December 2017How to Cite: Yadav, D., Kavaiya, A.R., Mohan, D., Prasad, R. (2017). Low Temperature Selective Catalytic Reduction (SCR) of NOx Emissions by Mn-doped Cu/Al2O3 Catalysts. Bulletin of Chemical Reaction Engineering & Catalysis, 12 (3): 415-429 (doi:10.9767/bcrec.12.3.895.415-429)

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Nevalainen, Pauliina, Niko Kinnunen, and Mika Suvanto. "Developmental Study of Soot-Oxidation Catalysts for Fireplaces: The Effect of Binder and Preparation Techniques on Catalyst Texture and Activity." Catalysts 9, no. 11 (November 15, 2019): 957. http://dx.doi.org/10.3390/catal9110957.

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An awareness of increasing climate and health problems has driven the development of new functional and affordable soot-oxidation catalysts for stationary sources, such as fireplaces. In this study, Al(OH)3, water glass and acidic aluminium phosphate binder materials were mixed with soot-oxidation catalysts. The effect of the binder on the performance of the Ag/La-Al2O3 catalyst was examined, while the Pt/La-Al2O3 catalyst bound with Al(OH)3 was used as a reference. Soot was oxidised above 340 °C on the Ag/La-Al2O3 catalyst, but at 310 °C with same catalyst bound with Al(OH)3. The addition of water glass decreased the catalytic performance because large silver crystals and agglomeration resulted in a blockage of the support material’s pores. Pt/La-Al2O3 bound with Al(OH)3 was ineffective in a fireplace environment. We believe that AgOx is the active form of silver in the catalyst. Hence, Ag/La-Al2O3 was shown to be compatible with the Al(OH)3 binder as an effective catalyst for fireplace soot oxidation.

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Journal articles on the topic 'Al2O3 catalysts'

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