铂助剂对钴基费托合成催化剂反应性能的影响

Effect of Pt promoter on performance of cobalt-based Fischer-Tropsch synthesis catalysts

采用沉淀法制备了氧化铝负载的钴基催化剂,然后通过等体积浸渍法添加不同负载量的铂,以改善费托合成钴基催化剂的原料转化效率和C+5烃类选择性。结果表明,铂助剂的引入降低了主活性组分钴(Co)的还原难度,促进了小粒径钴物种的形成,在一定程度上提高了催化剂活性,增加了C_(5)^(+)烃类收率。综合考虑催化剂性能和成本,Pt添加量为0.3%时效果最佳,在216℃、2.5 MPa、1 000 h^(-1)、V(H_(2))/V(CO)=2的反应条件下,CO转化率为58.34%,烃分布中甲烷选择性为7.62%,C_(5)^(+)烃选择性为82.71%。

Alumina supported cobalt-based Fischer-Tropsch catalysts are prepared by precipitation method.Then the catalysts with different loading amount of Pt are prepared by the incipient wetness impregnation to improve the conversion of CO and selectivity to C+5hydrocarbons over the catalysts.Results show that the addition of Pt facilitate the reduction of cobalt species and promotes the formation of cobalt particles in smaller size, which improves the reactivity of catalyst and the selectivity to C_(5)^(+) hydrocarbons over the catalyst.Considering the balance between the catalyst’s performance and cost, the catalyst containing 0.3% of Pt has the best effect, over which and under the optimal reaction conditions of 216℃,2.5 MPa, 1 000 h^(-1)and V(H_(2))/V(CO)=2,the conversion rate of CO is 58.34%,the selectivity of methane in hydrocarbon distribution is 7.62%,and the selectivity of C_(5)^(+) hydrocarbons is 82.71%.