The catalytic activity of platinum-loaded porous smectite-like clay minerals containing different divalent cations for butane hydrogenolysis and ethylene hydrogenation

Supported platinum catalysts were prepared using newly synthesized porous smectite-like clay minerals containing different divalent cations of Ni2+, C2+, Mg2+, and Zn2+ in trioctahedral sheets. Platinum was loaded on the clay minerals through the adsorption of metal precursors followed by the reduction with hydrogen. The activities of the catalysts prepared for n-butane hydrogenolysis and ethylene hydrogenation were shown to depend significantly on the support used, being in the order of Pt/SM (Ni) > Pt/SM(Co), Pt/SM(Mg) >> Pt/SM(Zn), where SM(M) denotes the smectite-like clay mineral containing M(2+) cation. The former three catalysts are much more active compared with a control Pt/SiO2 catalyst. The Pt/SM(Zn) catalyst is inactive, probably due to a toxic effect of Zn2+ on platinum. The high catalytic activities observed may be explained by high degrees of platinum dispersion for Pt/SM(Co) and Pt/SM(Mg) catalysts. The highest activity of Pt/SM(Ni) catalyst may be attributable to the presence of different reactive-sites more active than platinum. These active sites are reduced nickel species arising from the support, which are produced by platinum-catalyzed hydrogen reduction. (C) 1996 Academic Press, Inc.