甲烷制苯Mo/HZSM-5催化剂失活的研究  

Study of deactivation of a Mo/HZSM 5 catalyst

作　　者：谭平连[1] 徐竹生[1] 张涛[1] 陈来元[1] 高秀英[1] 

机构地区：[1]中国科学院大连化学物理研究所

出　　处：《天然气化工—C1化学与化工》1997年第5期17-21,共5页Natural Gas Chemical Industry

基　　金：国家自然科学基金

摘　　要：用ＤＴＡ－ＴＧ研究了Ｍｏ／ＨＺＳＭ－５上甲烷直接制苯的积炭－烧炭特性。用ＸＰＳ、ＮＨ３－ＴＰＤ、比表面测定考察了催化剂在反应前后性质的变化。结果表明，积炭是一个动态过程，催化剂上的酸中心、表面积和孔体积在反应初期下降较快，而后下降趋缓，与积炭量的变化相一致，这初步说明了积炭是从催化剂上的酸中心和微孔中开始进行的；结焦是Ｍｏ／ＨＺＳＭ－５上甲烷直接制苯失活的主要原因。钼的价态变化以及钼组份在反应中流失也是催化剂失活的因素之一。Coking decoking behavior of a Mo/HZSM 5 catalyst for direct aromatization of methane to benzene in the absence of oxygen has been studied by TG DTA, and changes in characteristics of the zeolite both before and after the reaction also investigated by XPS,NH 3 TPD, and surface area measurement. The results show that carbon accumulation on Mo/HZSM 5 is a motional process. The surface acid amount, BET surface area and micropore volume of the catalyst all decrease fast at the beginning of the reaction, and then slowly, as well as carbon accumulation, which indicates that carbon accumulation occurs first on the surface acid sites in the micropores of the zeolite. The most probable reason for catalyst deactivation is the serious carbon deposition on the catalyst. Meanwhile, changing of the oxidation state of and volatiling of the Mo species during reaction may cause deactivation of the catalyst, too.

关 键 词：甲烷 HZSM-5 脱氢聚合 苯 失活 钼 催化剂 

分 类 号：O625.11[理学—有机化学] O643.361[理学—化学]