Effect of the Calcination Temperature on the Catalyst Performance of ZrO_2-Supported Cobalt for Fischer-Tropsch Synthesis

摘要

The effect of the calcination temperature on the catalyst performance of Zr02-supported cobalt for Fischer-Tropsch synthesis is investigated. Results show that the size of the cobalt species particles of the ZrO_2-supported cobalt catalysts increases and their reducibility is enhanced with increasing calcination temperature. In addition, the extent of CO linear absorption and bridge absorption peak increases and then decreases with increasing calcination temperature. The results from the Fishcer-Tropsch synthesis show that the CO conversion rate increases and then decreases as the calcination temperature is increased. Catalyst selectivity for C_1 monotonically decreases, whereas that for C_5~+ increases. The changes in the CO conversion rate demonstrate a regularity consistent with the trend of the CO absorption peak extent. Meanwhile, the growth and enhanced reducibility of the cobalt species particles contribute to the generation of heavy hydrocarbons and explain the differences in product selectivity. Therefore, the appropriate calcination temperature facilitates an increase in the CO conversion rate of the ZrO_2-supported cobalt catalysts and results in a better Fischer-Tropsch synthesis product selectivity.