Fe-Mn催化剂CO+H2两段法合成汽油 Ⅱ. Mn在铁催化剂中的作用

Study on Fe-Mn catalyst for gasoline synthesis by CO+H2 two-stage process Ⅱ. Effect of Mn on Fe-based catalyst

Fe-Mn催化剂在CO+H_2合成汽油过程中表现出良好的催化性能(前报)。本文将反应结果与催化剂的表征相关联,阐明该催化体系中Mn的作用实质。从XRD、XPS等分析看出,Mn具有能改变铁催化剂体表相的结构、分散度和稳定金属活性位的作用。尤其是Mn对活性位的分隔和Fe-Mn尖晶石相的生成及抑制H_2的吸附等,是提高生成低碳烯烃选择性、反应活性和稳定性的主要原因。

The satisfactory performances of Fe-Mn catalyst for gasoline synthesis by CO+H_2 two-stage process were reported in the previous paper. This paper focuses on the essence of Mn's effect on the catalyst system via the correlation be ween experimental results and catalyst's characteristics. The results from XRD,XPS etc. show that Mn possesses functions of changing the structure both surface and bulk phase , dispersing and stabilizing the active sites of catalyst. The Mn's effects,such as isolation for the active sites, formation of Fe- Mn spinal structure and inhibition for H_2 adsorption etc. contribute mainly to the high activity, good olefin selectivity and stability of catalyst in CO+H_2synthe-