Effect of carbon support on Fischer-Tropsch synthesis activity and product distribution over Co-based catalysts
Effect of carbon support on Fischer-Tropsch synthesis activity and product distribution over Co-based catalysts
复制标题
碳载体对钴基催化剂上费托合成活性和产物分布的影响
DOI：
10.1016/j.fuproc.2012.12.006
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发表时间：
2013-06-01
影响因子：
7.5
通讯作者：
Li, Zhenhua
中科院分区：
文献类型：
--
作者：
Fu, Tingjun;Jiang, Yunhui;Li, Zhenhua
以SBA-15为模板剂，蔗糖为碳源，制备了有序介孔炭（CMK-3）。采用等体积浸渍法制备了以碳纳米管、CMK-3和活性炭为载体的钴催化剂。对它们的物理性质、形态和费托合成（FTS）活性进行了评价。结果表明，Co/CNTs和Co/CMK-3的纳米管中Co3O4颗粒主要分布在孔道内，而Co/AC的纳米管中Co3O4颗粒主要分布在孔道外。Co_3O_4颗粒大小与载体结构密切相关。在H2还原后，三种催化剂具有相似的钴颗粒尺寸。由于碳纳米管的特殊限制作用，Co/CNTs复合材料中钴的粒径得到了很好的保持。碳纳米管在高温氢气气氛中的稳定性优于CMK-3和AC，Co/CNTs催化剂的还原度高于其他两种催化剂。Co/CNTs良好的石墨化结构有利于Co和CO分子之间的电子转移。因此，Co/CNTs比Co/CMK-3和Co/AC催化剂具有更好的FTS性能。碳载体结构影响C5+选择性、C5+烃分布和CO周转频率。C2~C4烯烃/烷烃比与C5+选择性呈正相关。高烯烃含量和低空速有利于重烃的生产。(C)2012爱思唯尔有限公司版权所有。
The ordered mesoporous carbon (CMK-3) was prepared using SBA-15 as template and sucrose as carbon source. Co catalysts supported on CNTs, CMK-3 and AC were prepared by incipient wetness. Their physical properties, morphologies and Fischer-Tropsch synthesis (FTS) activities were assessed. It was found that Co3O4 particles mainly dispersed inside the tubes (or pores) of Co/CNTs and Co/CMK-3 but outside the pores of Co/AC. Co3O4 particle size depended closely on the support structure. After H-2 reduction, the three catalysts had a similar cobalt particle size. The cobalt particle size of Co/CNTs was maintained well due to the special confinement effect of CNTs. CNTs were more stable at high temperature in H-2 atmosphere than CMK-3 and AC and the reduction degree of Co/CNTs was higher than the other two catalysts. The good crystallized graphitic structure facilitated the electron transfer between the cobalt and CO molecules on Co/CNTs. So Co/CNTs had a better FTS performance than Co/CMK-3 and Co/AC catalysts. Carbon support structure influenced the C5+ selectivity, C5+ hydrocarbon distribution and CO turnover frequency. Furthermore, a positive relationship existed between C-2-C-4 olefin/paraffin ratio and C5+ selectivity. High olefin content and low space velocity benefit the heavy hydrocarbon production. (C) 2012 Elsevier B.V. All rights reserved.