Kinetics of the Selective Low-Temperature Oxidation of CO in H2-Rich Gas over Au/α-Fe2O3

Kahlich, M.J.; Gasteiger, Hubert A.; Behm, R. J.

doi:10.1006/jcat.1998.2333

Cited by 301 publications

(166 citation statements)

References 39 publications

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“…In an fuel processor, hydrogen would reach the PROX unit together with CO 2 and H 2 O; thus, a suitable PROX catalyst must also tolerate high amounts of CO 2 and H 2 O present in the reformate stream [196]. In this sense, Au/CeO 2 systems demonstrated sufficient stability with time on stream, in contrast to other gold catalysts, such as Au/Fe 2 O 3 [197] and Au/TiO 2 [198], which lost a significant part of their initial activity during the first hours of reaction. A good example of high stability is extracted from the paper of Deng et al [147], where an Au/CeO 2 -based catalyst with low gold content preserves its CO conversion and selectivity during 50 h of continuous operation under the presence of CO 2 and H 2 O.…”

Section: Preferential Co Oxidation (Co-prox)mentioning

confidence: 99%

Au/CeO2 Catalysts: Structure and CO Oxidation Activity

et al. 2016

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Abstract:In this comprehensive review, the main aspects of using Au/CeO 2 catalysts in oxidation reactions are considered. The influence of the preparation methods and synthetic parameters, as well as the characteristics of the ceria support (presence of doping cations, oxygen vacancies concentration, surface area, redox properties, etc.) in the dispersion and chemical state of gold are revised. The proposed review provides a detailed analysis of the literature data concerning the state of the art and the applications of gold-ceria systems in oxidation reactions.

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Section: Preferential Co Oxidation (Co-prox)mentioning

confidence: 99%

Au/CeO2 Catalysts: Structure and CO Oxidation Activity

et al. 2016

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“…Studies on gold supported catalysts have been mainly focused on gas-phase oxidation, such as CO oxidation [1][2][3][4], complete oxidation of hydrocarbons [5][6][7][8][9][10][11], selective oxidation [12][13][14][15][16][17][18][19][20], and water-gas shift (WGS) reaction [21][22][23][24]. Studies on the use of gold catalysts for the synthesis of fine chemicals in liquid phase have recently received much more attention.…”

Section: Introductionmentioning

confidence: 99%

Gold on titania: Effect of preparation method in the liquid phase oxidation

Dimitratos

Villa

Bianchi

et al. 2006

Applied Catalysis A: General

129

106

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The effect of preparation method (deposition-precipitation versus sol immobilisation method) and reduction method (calcination versus chemical reduction) on Au/TiO 2 catalysts for the liquid phase oxidation of glycerol has been studied. It was revealed that a different trend existed in terms of activity and distribution of products. The catalytic activity is shown to be dependent not only on the choice of the reduction method but also on the use of protective agent (PVA, THPC) for the stabilization of the gold colloids. In fact, the highest activity was found when a low temperature chemical reduction was employed on a Au/TiO 2 sample synthesised by the deposition-precipitation method. The use of a higher pre-treatment temperature or of a protective agent resulted in a lower activity but could be used to direct selectivity in oxidation reactions. The structural data (HRTEM and XPS) along with the catalytic results indicate that the combination of metallic Au 0 species with small particle size (2-5 nm) are responsible for the high activity observed in the liquid phase oxidation of glycerol. #

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“…Catalyst formulations found to be active in the PROX reaction can be classified as: gold based catalysts [5][6][7][8], supported Pt [5,[8][9][10][11][12], Rh [9], Ru [9,13], and bimetallic Pt-Sn [11,14] and other systems not containing metallic phase, such as CuO/CeO 2 [5,15]. These systems, as a rule, are also active in the low temperature CO oxidation.…”

Section: Introductionmentioning

confidence: 99%

Preferential CO oxidation in hydrogen (PROX) on ceria-supported catalysts, part II: Oxidation states and surface species on Pd/CeO2 under reaction conditions, suggested reaction mechanism

Pozdnyakova

Teschner

Wootsch

et al. 2006

Journal of Catalysis

203

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The aim of the PROX reaction is to reduce the CO content of hydrogen feed to proton exchange membrane fuel cells (PEMFC) by selective oxidation of CO in the presence of excess hydrogen. Both Pt and Pd on ceria are active in CO oxidation (without hydrogen) while Pd is poorly active in the presence of hydrogen. In this paper we aimed at finding the reasons of such behavior, using the same techniques for Pd/CeO 2 as for Pt/CeO 2 in Part I: catalytic tests, in-situ DRIFTS, high-pressure XPS, HRTEM and TDS. The reaction mechanism of CO oxidation (without hydrogen) was also examined. It does not occur via the exactly same mechanism on Pt and Pd/CeO 2 catalyst. In the presence of hydrogen (PROX) at low temperature (T=350-380 K), the formation of Pd β-hydride was confirmed by high-pressure in-situ XPS. Its formation greatly suppressed the possibility of CO oxidation, because oxygen both from gas phase and support sites reacted fast with hydride H to form water, and this water desorbed from Pd easily. Nevertheless, CO adsorption was not hampered here. These entities transformed mainly to surface formate and formyl (-CHO) species instead of oxidation as observed by DRIFTS. The participation of a low-temperature water-gas-shift type reaction proposed for the platinum system [Part I] was hindered. Increasing temperature led to decomposition of the hydride phase and a parallel increase in the selectivity towards CO oxidation was observed. However, it remained still lower on Pd/CeO 2 than on Pt/CeO 2 .

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Kinetics of the Selective Low-Temperature Oxidation of CO in H2-Rich Gas over Au/α-Fe2O3

Cited by 301 publications

References 39 publications

Au/CeO2 Catalysts: Structure and CO Oxidation Activity

Au/CeO2 Catalysts: Structure and CO Oxidation Activity

Gold on titania: Effect of preparation method in the liquid phase oxidation

Preferential CO oxidation in hydrogen (PROX) on ceria-supported catalysts, part II: Oxidation states and surface species on Pd/CeO2 under reaction conditions, suggested reaction mechanism

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