锆助剂含量对钴基费-托合成催化剂的影响

考察了锆助剂含量对钴基催化剂的结构及费－托合成反应性能的影响。结果表明，随着锆含量的增加，甲烷的生成受到抑制，重质烃选择性提高，重质烃合成的操作温度区间加宽，且催化剂仍保持较高的活性。ＴＰＲ，Ｈ２－ＴＰＤ，ＸＲＤ及ＥＸＡＦＳ等表征结果表明，锆助剂单层分散于硅胶表面，而钴以一定尺寸的聚集态存在；随着锆含量的增加，锆覆盖的硅胶表面增加，裸露的硅胶表面减小，而钴的分散度几乎不变。这使得钴锆界面增大，钴硅

Effect of ZrO2 Loadings on Catalytic Performance of Co/SiO2 for F-T Synthesis

The effect of ZrO 2 loadings on the structure and catalytic activity of Co based catalysts for F T synthesis was investigated. It was found that the addition of ZrO 2 enhanced the formation of heavy hydrocarbon and kept still high activity. The results of TPR, H 2 TPD, XRD and EXAFS indicated that ZrO 2 was dispersed in monolayer on SiO 2 while the Co species existed in certain agglomeration whose size was almost undisturbed by ZrO 2 loading. With the increase of ZrO 2 loading, the ZrO 2 covered silica surface increased whereas the Co dispersion kept fixed, resulting in a large Co ZrO 2 interface at the cost of Co SiO 2 interface. In thought of reactivity change, it might be concluded that the Co ZrO 2 interface favored the formation of heavy hydrocarbon. In addition, the hydrogen spillover from Co to ZrO 2/SiO 2 was evidenced by H 2 TPD.