用于F-T合成的沉淀铁催化剂的X射线光电子谱的研究

THE CHARACTERIZATION OF PRECIPITATED IRON CATALYST FOR FISHER-TROPSCH SYNTHESIS BY X-RAY PHOTOELECTRON SPECTROSCOPY

应用XPS研究了Fe-Cu-K-Si沉淀铁催化剂表面原子组成及其纵深分布、原子存在的化学形态及其在催化剂还原及合成气反应后的动态变化。研究结果表明,该催化剂表面是贫铁富Si、Cu,表层中各原子分布呈规律变化。研究获得丁Fe-Si相互作用的某些证据,这种相互作用导致铁的化学形态及催化特性的改变。

XPS is used to characterize Fe-Cu-K-Si precipitated catalysts. XPS characterization shows a surface enrichment of Si、Cu on the fresh catalysts surface while argon ion etching indicats a substantial Fe、Cu、K、Si、C concentration gradient over a few nm into it.This in-situ XPS investigation of catalysts before and after H_2 reduction and exposure to synthesis gas gives the information of the variation of atom composition and chemical state of the catalyst surface. The interaction between Fe-Si leads to a change of chemical state and catalytic behavior of Fe.