Characterization and catalytic activity of Al2O3-supported Pt-Co catalysts

A series of Pt-Co supported on gamma-alumina have been prepared from acetylacetonate precursors with 2 wt% as total metal loading and different atomic contents. The catalysts were characterized by hydrogen chemisorption, TPR, TEM, XPS and they were tested in two different reactions: methylcyclohexane dehydrogenation and n-butane hydrogenolysis. The results have shown that platinum is in reduced state and cobalt is mainly in an oxidized state. Additionally, TEM results evidence an increase in the particle size as cobalt content is increased, in agreement with chemisorption results. Monometallic platinum and cobalt supported catalysts showed large differences in the dehydrogenation of methylcyclohexane, while the bimetallic catalysts have activities in the same order of magnitude with respect to the pure platinum catalyst. In n-butane hydrogenolysis all the catalysts show a large decrease in activity compared to other, previously studied Pt-based bimetallic catalysts.