35S Tracer Study of the Effect of Support on the Nature of the Active Sites of Co(Ni)Mo Sulphide Catalysts Supported on Al2O3and Activated Carbon

The influence of the support (Al2O3 and activated carbon) on the activity of Mo, NiMo, and CoMo catalysts in thiophene hydrogenolysis is studied using 35S as a tracer. The carbon-supported catalysts have more active sites than their aluminasupported counterparts, while the turnover frequencies of these sites are similar. Thiophene desulfurization and the hydrogenation of the resulting C4 olefins take place at the same Mo sites. Tracer tests have demonstrated that the active sites in the catalysts examined are identical and the support has an effect only on their concentration.