Abstract: The role of the CeO2 promoter in the Co-CeO2/SiO2 catalyst playing in Fischer-Tropsch synthesis (FTS) was investigated by means of the D2 pulse reaction. The D2 pulse reaction results over Co-CeO2/SiO2 and Co/SiO2 catalysts showed that the addition of CeO2 increased the catalytic activity of Co/SiO2 for the H-D isotopic exchange and the reactivity of H from Si-OH for CO hydrogenation. The addition of CeO2 increased the total amount of active carbon species on the surface of Co/SiO2 and made the chain growth unit -[KG-20x]CH2[KG-45x]- the dominating one, which consequently benefited the increase of the FTS reactivity and the chain growth possibility. The addition of CeO2 into Co/SiO2 also improved the hydrogenation reactivity of carbon atoms on the surface of Co-CeO2/SiO2, which led to a decrease in carbon deposition.

Key words: cobalt, ceria, silica, supported catalyst, promoter, Fischer-Tropsch synthesis, D2 pulse reaction, H-D isotopic exchange