Additives and Support Effects on Pt Catalysts Studied by the Competitive Hydrogenation of Benzene and Toluene

Resume Le rapport des coefficients d'adsorption du C 7 H 8 et C 6 H 6 sur Pt, K T/B , a ete determine par une analyse de la cinetique des reactions d'hydrogenation competitives entre ces deux hydrocarbures. Une correlation a ete etablie entre les valeurs de K T/B et le caractere deficitaire en electrons du platine. Ce rapport permet de suivre avec precision les modifications des proprietes electroniques de Pt induites par le support ou les additifs. Abstract The ratio of the adsorption coefficients of C 7 H 8 and C 6 H 6 ,K T/B , has been determined by the kinetic analysis of the competitive hydrogenation reactions between these two hydrocarbons. It has been shown that there is a correlation between K T/B and the electron deficient character of Pt. This can be used to test the modifications of the electronic properties of metal induced by support or additives.