还原温度对Co/ZnO催化剂的F-T合成反应性能影响

Influence of reduction temperature on reactive performance of Co/ZnO catalyst for Fischer-Tropsch synthesis

采用沉淀-浸渍法制备Co/ZnO催化剂,研究还原温度对Co/ZnO催化剂F-T合成反应性能影响。结果表明,催化剂Co/ZnO适宜在较低温度还原,Co负载质量分数5%和10%的催化剂最佳还原温度分别为260℃和250℃。还原温度与催化剂活性之间的关系取决于Co/ZnO催化剂上Co的分布状态,氧化态Co以约50 nm的颗粒存在于ZnO表面,容易被氢还原。低温还原的Co基催化剂是浆态床F-T合成的良好催化剂。

Co/ZnO catalysts were prepared by precipitation-impregnation method. The influence of reduction temperature on catalytic performance of Co/ZnO catalysts for Fischer-Tropsch synthesis was investigated. The results showed that Co/ZnO catalyst for Fischer-Tropsch synthesis was fit to be reduced at low temperature. Compared with the catalysts reduced at high temperature,the catalysts with Co loadings of 5wt% and lOwt% reduced at 260 ℃ and 250℃ respectively showed higher CO conversion. The relation between reduction temperature and catalyst activity was decided by cobalt distribution state on Co/ZnO cat- alyst. Oxidized cobalt with particle sizes about 50 nm existed on ZnO surface, and was easily reduced by hydrogen. The cobalt-based catalyst reduced at low temperature is a good candidate for slurry-bed Fischer- Tropsch synthesis.