Evaluation of the metal-support interactions -: Case of platinum-supported catalysts:: effect of the support nature and the metallic dispersion

被引:20
作者
Douidah, A
Marécot, P
Szabo, S
Barbier, J
机构
[1] Univ Poitiers, CNRS, UMR 6503, Catalyse Chim Organ Lab, F-86022 Poitiers, France
[2] Hungarian Acad Sci, Cent Res Inst Chem, H-1525 Budapest, Hungary
关键词
metal-support interactions; excess free energy; platinum-supported catalysts; platinum oxidation;
D O I
10.1016/S0926-860X(01)00627-5
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 potentials of platinum oxidation according to the metallic particle size and the nature of the support have been evaluated. The use of the Fe3+/Fe2+ redox system potentials of platinum oxidation to be defined according to the dispersion of platinum and the nature of the support. By the use of the Gibbs-Helmoltz law (DeltaG = -zF Delta E), the comparison with bulk platinum allows the platinum excess free energy to be calculated. It thus appears that the platinum-support interaction decreases following the sequence: Al2O3 > C > SiO2. However, the most important parameter seems to be the size of the particle. Thus, the small particles are oxidised more easily by the Fe3+/Fe2+ redox system. At the end of the process, the size of the most stable particles is defined by a compromise between a decrease of the stability when the dispersion increases and an increase of the metal-support interaction when the particle size decreases. (C) 2002 Elsevier Science B.V. All rights reserved.
引用
收藏
页码:21 / 31
页数:11
相关论文
共 37 条
[1]   INFLUENCE OF CARRIER DOPING ON CATALYTIC PERFORMANCE OF TITANIUM-DIOXIDE SUPPORTED PLATINUM [J].
AKUBUIRO, EC ;
VERYKIOS, XE ;
IOANNIDES, T .
APPLIED CATALYSIS, 1989, 46 (02) :297-312
[2]  
Anderson J.R., 1975, Structure of metallic catalysts
[3]  
[Anonymous], CATALYSIS
[4]  
[Anonymous], 1985, STANDARD POTENTIALS
[5]   INVESTIGATION OF THE SMSI PHENOMENON WITH TIO2/RU/SIO2 MODEL-DISPERSED CATALYSTS [J].
BADYAL, JPS ;
LAMBERT, RM ;
HARRISON, K ;
RILEY, CCA ;
FROST, JC .
JOURNAL OF CATALYSIS, 1991, 129 (02) :486-496
[6]  
BAKER RTK, 1986, P ACS S SERIES, V298
[7]   HYDROGEN-OXYGEN TITRATION METHOD FOR MEASUREMENT OF SUPPORTED PLATINUM SURFACE AREAS [J].
BENSON, JE ;
BOUDART, M .
JOURNAL OF CATALYSIS, 1965, 4 (06) :704-&
[8]   REVERSAL OF THE SMSI STATE ON PT/TIO2 BY CO HYDROGENATION [J].
BLANKENBURG, KJ ;
DATYE, AK .
JOURNAL OF CATALYSIS, 1991, 128 (01) :186-197
[9]   MORPHOLOGY AND SITE BLOCKING EFFECTS ON CHEMISORPTION PROPERTIES AND REACTIVITY OF PT/TIO2 AND SULFIDED PT/AL2O3 CATALYSTS [J].
BONNEVIOT, L ;
HALLER, GL .
JOURNAL OF CATALYSIS, 1991, 130 (02) :359-373
[10]   ON SPECIFIC ACTIVITY OF PLATINUM CATALYSTS [J].
BOUDART, M ;
ALDAG, A ;
BENSON, JE ;
DOUGHARTY, NA ;
HARKINS, CG .
JOURNAL OF CATALYSIS, 1966, 6 (01) :92-+