A model of metal-oxide support interaction for Rh on TiO2
1983; Elsevier BV; Volume: 82; Issue: 2 Linguagem: Inglês
10.1016/0021-9517(83)90194-x
ISSN1090-2694
Autores Tópico(s)Metallurgical and Alloy Processes
ResumoUsing the Rh/TiO2 catalyst system, a simple model for the different kinds of interaction that occur following a low- and a high-temperature reduction of Group VIII noble metals supported on TiO2, was developed. The model proposes a delocalized transfer of charge from Rh to TiO2 after low-temperature reduction and a localized (chemical bonding) transfer of charge from the support to Rh after a high-temperature reduction. In addition, it is suggested that migration of a reduced species of the support is responsible, in part, for the depression of hydrogenolysis activity following a high-temperature reduction. The experimental evidences for the latter comes from comparing H2 and H atom reduction, the kinetics of the onset of strong-metal-support interaction, and a strong analogy between group VIII-group Ib and group VIII-TiO2 interaction effects on structure-sensitive and insensitive reactions. The kind of charge transfer is based on observed effects on kinetic parameters and previously reported spectroscopic experiments.
Referência(s)