硫化的MoO_3/γ—Al_2O_3催化剂的表面结构和价态的研究  

A STUDY OF VALENCE AND SURFACE STRUCTURE FOR SULFIDED MoO_3/γ-Al_2O_3 CATALYAT

作　　者：伏义路[1] 唐曦白 黄志刚[1] 范崇政[1] 季明荣[2] 吴建新[2] 

机构地区：[1]中国科学技术大学近代化学系 [2]中国科学技术大学结构与成份分析中心

出　　处：《物理化学学报》1989年第3期327-332,共6页Acta Physico-Chimica Sinica

基　　金：国家自然科学基金

摘　　要：本文应用XPS、ESR和TEM等手段研究了硫化的MoO_3/γ-Al_2O_3催化剂样品,在不同钼含量、不同硫化条件以及进行甲烷反应前后,其表面结构和价态的变化规律。观察到硫化时Mo^(+6)。还原为Mo^(+5)和Mo^(+4)的变化过程。硫化除了生成S^(-2)价态外,还有硫的高价中间态生成。证明了经甲烷化反应后,表面上的MoS_2晶粒明显长大。The surface structure and the valence change on sulfided MoO_3/γ-Al_2O_3 catalyst samples were investigated at different sulfidation conditions and before or after methanation reaction using XPS, ESR and TEM methods. The main results were obtained as following. The most of Mo^(+6) were easily reduced to Mo^(+4) during the samples were sulfided. Very small amount of Mo^(+5) existed and decreased when the sulfidation time was increased. More amount of Mo^(+5) was only detected by XPS on the samples of lower Mo content at lower reduction temperature and at shorter sulfidation time. The major valency of sulfur was -2 during the sulfidation proceeded. A small amount of high valence sulfur was detected and vanished during prolongation of sulfidation time. No change of the valence of Mo or S was observed after reaction for 8hrs. Itwas demonstrated by TEM photogragh and diffraction pattern that MoS_2 microcrystal grew up, remarkably on the sample surface after methanation reaction.

关 键 词：钼催化剂 硫化态 表面结构 价态 

分 类 号：TQ426.81[化学工程]