Hydrogenation of tetralin on silica–alumina-supported Pt catalysts II. Influence of the support on catalytic activity

The interactions between an oxidic support and Pt particles were explored in a series of platinum catalysts supported on amorphous silica–alumina used for the hydrogenation of tetralin and the hydrogenolysis of neopentane. The activity of the nanosized Pt particles increased with increasing intermediate electronegativity of the support for all supports with accessible Lewis acid sites. A compensation effect between the preexponential factor and the apparent energy of activation was observed for both reactions, attributed to the stronger adsorption of the reactants and intermediates on Pt induced by the increasingly electronegative supports. The product distribution in tetralin hydrogenation also points to stronger adsorption on Pt with increasing intermediate electronegativity of the support. X-ray absorption near-edge structure (XANES) findings indicate that the stronger interaction of the reactants is related to a reduced electron density on the platinum particles.