Characterization and Fischer-Tropsch synthesis (FTS) under classical reaction conditions for Th, Zr, Mn, Ce promoted Co/HMS catalysts were investigated. The FTS activity order was found to be: Co-1.5Th/HMS > Co/ HMS>Co-1.5Zr/HMS>Co-1.5Mn/HMS>Co-1.5Ce/HMS under the conditions of H2/CO = 2.0, T = 463 ~ 523 K, p = 2.0 MPa, GHSV = 500 h"!, which was owing to the lower cobalt reducibility for Mn promoted Co/HMS and the cobalt oxidation at the beginning of FTS for Zr and Ce promoted Co/HMS despite their higher cobalt reducibility. The highest CO2 selectivity was obtained for Mn and Ce promoted Co/HMS among all the catalysts, so the H2/CO ratio on the catalyst surface increased during FTS in contrast with Co-1.5Th/HMS, Co/HMS and Co-1. 5Zr/HMS. The increasing surface H2/CO ratio led to higher hydrogenation ability, which was further confirmed by low olefin and paraffin ratio from hydrocarbon distribution for Mn and Ce promoted Co/HMS catalysts. High hydrogenation ability for Co-1.5Mn/HMS and Co-1. 5Ce/HMS presented the high methane and low chain propagation.

Key words: COBALT, ZIRCONIUM, GERMANIUM, CERIUM, XRD, TPR, CATALYSIS