Structure-activity relationships in catalysis by metals: some aspects of particle size, bimetallic and supports effects

Some aspects of particle size, bimetallic formulation and metal-support interaction on the catalytic properties of supported metal catalysts in the hydrogenolysis of C-C and C-halogen bonds, and the hydrogenation of nitroaromatics and alpha,beta-unsaturated aldehydes are presented. The influences of these parameters on the kinetics, the mechanism, the nature of adsorbed intermediates and the consequences on turnover frequency and selectivity are highlighted. It is shotwn, in particular, how the topology of the active site, and the coordination of the metal atoms, can determine the nature of the surface intermediates and, in fine, the orientation of the reaction. This is a review mainly based on the researches carried out over two decades in the "Laboratoire de Materiaux Catalytiques et Catalyse en Chimie Organique, UMR 5618 ENSCM-CNRS". (C) 1998 Elsevier Science S.A. All rights reserved.