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Autothermal Reforming
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Shudong Wang – One of the best experts on this subject based on the ideXlab platform.
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Autothermal Reforming of methane over rh ce0 5zr0 5o2 catalyst effects of the crystal structure of the supports
Fuel Processing Technology, 2010Co-Authors: Zhongsha Yua, Lei Cao, Shudong WangAbstract:Abstract Autothermal Reforming of methane (ATR) was studied over Rh catalysts supported on Ce 0.5 Zr 0.5 O 2 solid solution, which were synthesized by four different routes, including reverse micro-emulsion (ME), co-precipitation (CP), urea-combustion (UC) and sol–gel (SG) method. The textural and structural properties of the as-prepared solid solutions were carefully examined by means of BET, TEM, XRD and Raman techniques. Results showed that the ME sample exhibited a single cubic phase, whereas tetragonal or mixed phases such as cubic CeO 2 -rich and tetragonal ZrO 2 -rich phases, were found in the case of CP, UC and SG. Vegard’s rule revealed that the homogeneity of these as-prepared solid solutions followed the order of ME > CP > UC > SG. TPR and CO-pulse experiments were adopted to evaluate the reducibility and the oxygen storage capacity (OSC) of the catalysts. It was found that the more homogenous the solid solution is, the more reducibility it is, i.e. both the reducibility and OSC followed the same order as that of homogeneity. Rh/ME showed the highest activity and H 2 /CO ratio and such performance was maintained without significant loss during 10 h experiment. On the contrary, the other three catalysts having mixed phases showed remarkably deactivation in terms of H 2 /CO due to the loss of BET area. To elucidate the resistance toward carbon formation of these catalysts, methane decomposition experiments and following temperature-programmed-oxidation (TPO) were studied. As expected, the resistance toward carbon formation could be enhanced by the improved OSC of the catalyst.
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correlation between catalytic selectivity and oxygen storage capacity in Autothermal Reforming of methane over rh ce0 45zr0 45re0 1 catalysts re la pr nd sm eu gd tb
Catalysis Communications, 2009Co-Authors: Zhongsha Yua, Lei Cao, Shudong WangAbstract:Trivalent rare-earth (RE = La, Pr, Nd, Sm, Eu, Gd, Tb)-doped Ce0.45Zr0.45RE0.1 solid solutions were synthesized via reverse micro-emulsion method and the catalytic performance of the Rh-supported catalysts was investigated in Autothermal Reforming of methane (ATR). It was found that CH4 conversion went through a maximum as a function of oxygen storage capacity (OSC) value of the support. Higher OSC will help to enhance the reactivity toward water-gas-shift (WGS) reaction, resulting higher H-2/CO ratio. A striking correlation between OSC and H-2/CO ratio was observed, which presented a maximum for the Rh/CZLa (3.4) and a minimum for the Rh/CZTb (2.6) catalysts. (C) 2009 Elsevier B. V. All rights reserved.
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Autothermal Reforming of methanol in a mini reactor for a miniature fuel cell
International Journal of Hydrogen Energy, 2007Co-Authors: Chunxi Zhang, Na Liu, Shudong WangAbstract:Abstract A novel mini-reactor for hydrogen production has been successfully fabricated, which integrates one Reforming chamber, one catalytic combustion chamber and two preheating chambers. It can be started up at room temperature by the combustion of liquid methanol in the combustion chamber within 10 min , and it also can keep self-sustained, i.e. without any external heating during the operating process. This reactor has been tested for carrying out the reaction of Autothermal Reforming of methanol for hydrogen production. The reactor performance has been investigated using three crucial parameters, namely, the molar ratios of water/methanol, oxygen/methanol and the flow distribution, respectively. The experimental runs have demonstrated the optimal methanol conversion of 96.4%, containing 51.04% H 2 , 26.68% N 2 , 2.12% CO and 20.16% CO 2 in the reformed gas. Furthermore, the reformer which can supply reformed gas at the maximum flow rate of 125 l (STP)/h has been integrated with a miniature fuel cell, the small power system can produce continuous power at the energy density of 92 mW / cm 2 for 4 h.
Lars J Pettersso – One of the best experts on this subject based on the ideXlab platform.
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evaluation of co la and mn promoted rh catalysts for Autothermal Reforming of commercial diesel aging and characterization
Applied Catalysis B-environmental, 2015Co-Authors: Moa Z Granlund, Marita Nilsso, Lars J Pettersso, Kjell Jansso, Jazae DawodyAbstract:In this study, three bimetallic catalysts are evaluated for Autothermal Reforming (AIR) of fuels (1 wt.% Rh and 6 wt.% X (X= Co, La or Mn) supported on high-surface area CeO2-ZrO2). The catalysts a …
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zone coated rh based monolithic catalyst for Autothermal Reforming of diesel
Applied Catalysis B-environmental, 2011Co-Authors: Xanthias Karatzas, Jazae Dawody, A W Gra, Erik Elm Svensso, Lars J PetterssoAbstract:Abstract In this work we present results of hydrogen generation from diesel via Autothermal Reforming (ATR) obtained with monolithic catalysts consisting of either one or two layers of monometallic Rh and bimetallic RhPt washcoats. The Rh metal loading of the monometallic washcoats was varied between 0.5, 1.0 and 3.0 wt%, while the weight ratio of Rh:Pt in the bimetallic washcoats was kept constant at 1:1. Furthermore, non-doped and CeLa-doped catalysts were also tested to detect differences in catalyst activity. The catalysts consisting of two layers of washcoats were termed zoned catalysts and each layer was applied to some given length in the axial direction of the monolith. All catalysts were prepared by impregnation using the incipient wetness technique with δ-Al2O3 as support and deposited onto 400 cpsi cordierite monoliths. A total of eight catalysts, including both single layered and zone-coated, were tested in a bench-scale reactor using low-sulfur diesel as fuel at operating conditions H2O/C = 2.5, O2/C = 0.49 (λ = 0.33), GHSV = 17,000 h−1 and P = 1 atm. The results showed that the zoned catalyst, covered with the two washcoats Rh1.0Pt1.0–Ce10La5.0/δ-Al2O3 and Rh3.0–Ce10La10/δ-Al2O3, respectively, was most active in terms of fuel conversion and hydrogen production. The zoned catalyst’s long-term performance and stability was also evaluated in a full-scale reactor using low-sulfur and Fischer–Tropsch diesels at operating conditions H2O/C = 2.5, O2/C = 0.49 (λ = 0.33), GHSV = 10,800 h−1, P = 1 atm, and at H2O/C = 2.4, O2/C = 0.39 (λ = 0.26), GHSV = 10,200 h−1, P = 1 atm, respectively. The results showed that high fuel conversion and hydrogen production were obtained from both fuels. In addition, partial oxidation and steam Reforming reactions were identified by closely studying the distribution of the analyzed product gas composition and the temperature measurements. Fresh and aged samples of the catalysts were characterized by N2-BET, H2 chemisorption, XRD, H2-TPR, O2-TPO and XPS analyses.
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catalytic properties of pd supported on zno znal2o4 al2o3 mixtures in dimethyl ether Autothermal Reforming
Applied Catalysis B-environmental, 2009Co-Authors: Marita Nilsso, Kjell Jansso, Pete Jozsa, Lars J PetterssoAbstract:The catalytic properties of Pd supported on mixtures of zinc oxide, zinc aluminate, and alumina, prepared from gamma-alumina and zinc nitrate, were studied for Autothermal Reforming (ATR) of dime …
Theodore Krause – One of the best experts on this subject based on the ideXlab platform.
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bimetallic ni rh catalysts with low amounts of rh for the steam and Autothermal Reforming of n butane for fuel cell applications
Applied Catalysis A-general, 2010Co-Authors: Magali Ferrando, Jeremy A Kropf, Theodore KrauseAbstract:Mono-metallic nickel and rhodium catalysts and bimetallic Ni-Rh catalysts supported on La-Al{sub 2}O{sub 3}, CeZrO{sub 2} and CeMgOx were prepared and evaluated for catalyzing the steam and Autothermal Reforming of n-butane. The binary Ni-Rh supported on La-Al{sub 2}O{sub 3} catalysts with low weight loading of rhodium exhibited higher H{sub 2} yields than Ni or Rh alone. The Ni-Rh/CeZrO{sub 2} catalyst exhibited higher performance and no coke formation, compared to the same metals on other supports. A NiAl{sub 2}O{sub 4} spinel phase was obtained on all Ni and Ni-Rh catalysts supported on La-Al{sub 2}O{sub 3}. The presence of rhodium stabilized the spinel phase as well as NiOx species upon Reforming while Ni alone was mostly reduced into metallic species. Extended X-ray absorption fine-structure analysis showed evidence of Ni-Rh alloy during preparation and even further after an accelerated aging at 900C in a H{sub 2}/H{sub 2}O atmosphere.
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rare earth first row transition metal perovskites as catalysts for the Autothermal Reforming of hydrocarbon fuels to generate hydrogen
Applied Catalysis A-general, 2008Co-Authors: Jennife R Mawdsley, Theodore KrauseAbstract:Abstract Perovskite oxides (ABO 3 ) containing rare earth elements on the A-site and first-row transition metal elements on the B-site were studied as catalysts for Autothermal Reforming of liquid hydrocarbon fuels to produce hydrogen for fuel cell systems. Experiments were conducted in a fixed bed microreactor at temperatures of 600–800 °C and gas-hourly space velocities (GHSV) ranging from 4600 to 28,000 h −1 using 2,2,4-trimethylpentane (isooctane) as a surrogate fuel. We have found that the two binary oxides, LaNiO 3 and LaCoO 3 , produced high yields of H 2 , but were not structurally stable. These perovskites decomposed to La 2 O 3 and Ni/NiO or Co/CoO under the reducing conditions present in the reformer. Three other binary oxides, LaCrO 3 , LaFeO 3 , and LaMnO 3 , were structurally stable but significantly less active than LaNiO 3 and LaCoO 3 . The partial substitution of chromium, iron, aluminum, gallium, or manganese on the B-site of LaNiO 3 to yield LaB x Ni 1− x O 3 was shown to improve the structural stability without a significant decrease in the H 2 yield. The effects of substituting rare earth elements for La and the substitution of alkaline earth elements on the A-site (La 1− y A y B x Ni 1− x O 3 ) on catalyst performance and stability were also investigated. Finally, La 0.8 Sr 0.2 M 0.9 Ni 0.1 O 3 catalysts (where M = Cr, Mn, or Fe) were tested with a “benchmark fuel” mixture containing from 0 to 50 ppmw sulfur. These tests showed that using chromium as a stabilizing element in LaNiO 3 imparts the most sulfur tolerance.
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role of the oxide support on the performance of rh catalysts for the Autothermal Reforming of gasoline and gasoline surrogates to hydrogen
Applied Catalysis A-general, 2006Co-Authors: Magali Ferrando, Theodore KrauseAbstract:Abstract Catalysts consisting of 2 wt% Rh deposited on Gd-CeO2, Y-ZrO2, γ-Al2O3, La-Al2O3, and CaAl12O19 were tested for the Autothermal Reforming (ATR) of isobutane and sulfur-free gasoline. The catalysts were characterized for activity by microreactor tests and temperature-programmed reduction (TPR), and for physical properties by surface area measurements, CO chemisorption, X-ray diffraction (XRD), and extended X-ray absorption fine structure (EXAFS) analyses. The order of activity for ATR of isobutane was Rh/La-Al2O3 > Rh/Y-ZrO2 > Rh/Gd-CeO2 > Rh/γ-Al2O3 > Rh/CaAl12O19, which paralleled the ranking of the catalysts based on the dispersion and reducibility of Rh, with Rh/La-Al2O3 having the highest dispersion and the lowest reduction temperature. After subjecting the catalysts to an accelerated ageing process, the activity for ATR of isobutane was similar for all catalysts except for Rh/Gd-CeO2, which experienced a significant loss in steam Reforming activity. Rhodium dispersion measurements confirmed that the ageing process had caused Rh to sinter on all of the supports. A major conclusion from this study is that the primary effect of the support was on the dispersion of Rh.