Mechanisms of CO oxidation reaction and effect of chlorine ions on the CO oxidation reaction over Pt/CeO2 and Pt/CeO2/γ-Al2O3 catalysts

被引：78
作者：
Oran, U [1 ]
Uner, D [1 ]
机构：
[1] Middle E Tech Univ, TR-06531 Ankara, Turkey
来源：
APPLIED CATALYSIS B-ENVIRONMENTAL | 2004年 / 54卷 / 03期
关键词：
CO oxidation; platinum; ceria; alumina; reaction mechanism; chlorine poisoning;
D O I：
10.1016/j.apcatb.2004.06.011
中图分类号：
O64 [物理化学（理论化学）、化学物理学];
学科分类号：
070304 ; 081704 ;
摘要：
The reaction orders and activation energies of CO oxidation reaction over Pt/gamma-Al2O3, Pt/CeO2 and Pt/CeO2/Y-Al2O3 were investigated for stoichiometric gas mixtures. The effect of residual chlorine originating from catalyst precursors on the CO oxidation activity of Pt/gamma-Al2O3, Pt/CeO2 and Pt/CeO2/gamma-Al2O3 was also studied. Indirect evidence was collected indicating that platinum was selectively deposited on alumina surface when Pt/CeO2/gamma-Al2O3 catalyst was prepared from the physical mixture of pure oxides. The reaction orders of CO and O-2 was found approximately as -2.0 and +1.0, respectively, over the Pt/gamma-Al2O3 catalyst, but as -1.0 and 0.0 over the Pt/CeO2 and Pt/CeO2/gamma-Al2O3 catalysts. The activation energy of CO oxidation reaction over Pt/gamma-Al2O3 catalyst under stoichiometric conditions was around 120.0 kJ/mol. On the other hand, over Pt/CeO2 catalysts activation energies were measured to be around 70 kJ/mol. Surface reaction mechanisms were postulated to explain the differences in the reaction orders and activation energies. (C) 2004 Elsevier B.V. All rights reserved.
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页码：183 / 191
页数：9
相关论文
共 31 条
[1]   KINETICS OF CO OXIDATION ON SINGLE-CRYSTAL PD, PT, AND IR [J].
BERLOWITZ, PJ ;
PEDEN, CHF ;
GOODMAN, DW .
JOURNAL OF PHYSICAL CHEMISTRY, 1988, 92 (18) :5213-5221
[2]   Surface energies and heats of oxygen adsorption in ceria/ceria-zirconia solid solutions: Analysis by semiempirical interacting bonds method [J].
Bulgakov, NN ;
Sadykov, VA ;
Lunin, VV ;
Kemnitz, E .
REACTION KINETICS AND CATALYSIS LETTERS, 2002, 76 (01) :111-116
[3]   The effects of residual chlorine on the behaviour of platinum group metals for oxidation of different hydrocarbons [J].
Cant, NW ;
Angove, DE ;
Patterson, MJ .
CATALYSIS TODAY, 1998, 44 (1-4) :93-99
[4]   A simplified approach to determine the activation energies of uncatalyzed and catalyzed combustion of soot [J].
Dernaika, B ;
Uner, D .
APPLIED CATALYSIS B-ENVIRONMENTAL, 2003, 40 (03) :219-229
[5]   Pd/Ce0.6Zr0.4O2/Al2O3 as advanced materials for three-way catalysts -: Part 1.: Catalyst characterisation, thermal stability and catalytic activity in the reduction of NO by CO [J].
Di Monte, R ;
Fornasiero, P ;
Kaspar, J ;
Rumori, P ;
Gubitosa, G ;
Graziani, M .
APPLIED CATALYSIS B-ENVIRONMENTAL, 2000, 24 (3-4) :157-167
[6]   Modification of the redox behaviour of CeO2 induced by structural doping with ZrO2 [J].
Fornasiero, P ;
Balducci, G ;
DiMonte, R ;
Kaspar, J ;
Sergo, V ;
Gubitosa, G ;
Ferrero, A ;
Graziani, M .
JOURNAL OF CATALYSIS, 1996, 164 (01) :173-183
[7]   Contribution of cerium/zirconium mixed oxides to the activity of a new generation of TWC [J].
González-Velasco, JR ;
Gutiérrez-Ortiz, MA ;
Marc, JL ;
Botas, JA ;
González-Marcos, MP ;
Blanchard, G .
APPLIED CATALYSIS B-ENVIRONMENTAL, 1999, 22 (03) :167-178
[8]   Effects of redox thermal treatments and feedstream composition on the activity of Ce/Zr mixed oxides for TWC applications [J].
González-Velasco, JR ;
Gutiérrez-Ortiz, MA ;
Marc, JL ;
Botas, JA ;
González-Marcos, MP ;
Blanchard, G .
APPLIED CATALYSIS B-ENVIRONMENTAL, 2000, 25 (01) :19-29
[9]   Kinetics, FTIR, and controlled atmosphere EXAFS study of the effect of chlorine on Pt-supported catalysts during oxidation reactions [J].
Gracia, FJ ;
Miller, JT ;
Kropf, AJ ;
Wolf, EE .
JOURNAL OF CATALYSIS, 2002, 209 (02) :341-354
[10]   LOW-TEMPERATURE CARBON-MONOXIDE OXIDATION ON PT(111) - DEPENDENCE OF APPARENT ACTIVATION-ENERGY ON REACTANT GAS-COMPOSITION [J].
HARDACRE, C ;
ORMEROD, RM ;
LAMBERT, RM .
CHEMICAL PHYSICS LETTERS, 1993, 206 (1-4) :171-174
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