Evidence for support effects in metal oxide supported cobalt catalysts

AbstractCobalt supported on a number of different metal oxides are often used in the Fischer–Tropsch (FT) reaction. No obvious rationale for the composition of the metal oxide used exists. In this paper we examine the possibility that some form of interaction between the metal and the metal oxide support exists which enhances the activity of the Co metal. To this effect, we have supported Co metal on a series of metal oxides of different degrees of reducibility: (i) Al2O3 which is unreducible under FT conditions, (ii) ZrO2 which can be reduced to a small extent under FT conditions, and (iii) ZnO which can be reduced to a measurable degree under FT conditions. The postulate was that the more reducible support will have the greater number of trapped electrons at anion vacancies, and so will have the greater possibility of transferring these electrons from the support to the metal, giving rise to a sequentially greater metal/metal oxide interaction. We have previously shown that temperature programmed desorp...