摘要
对商用ZSM-5分子筛进行水蒸汽处理和水蒸汽-盐酸相结合处理,研究了不同温度下水蒸气处理的ZSM-5分子筛的结构、酸性及催化乙醇脱水制乙烯反应性能。比较了水蒸气改性和水蒸气-盐酸溶液相结合改性两种方法对ZSM-5分子筛结构、酸性及催化稳定性的影响。结果表明,水蒸汽处理使ZSM-5分子筛发生骨架脱铝,酸中心数量减少,酸强度减弱,但介孔增多,从而使乙烯选择性及催化稳定性提高;水蒸汽处理后再进行盐酸酸洗,二次孔或中孔减少,催化稳定性得到提高,但远低于水蒸气改性催化剂。
The commercial ZSM-5 zeolite catalyst was been treated with steam and steam combined with HCl solution. The structure, acidity and catalytic performance of the treated ZSM-5 zeolite at different temperatures were investigated. The effects of the steam and steam combined with HCl treatment on the structure, acid and catalytic stability were compared. Results show that after steam treatment, some of Al was removed from the framework of zeolite. This led to a decrease in the strength and amount of acidic sites and an increase of mesoporous structure. As a result, ethylene selectivity and life time of catalyst increased significantly. Compared to the steam treatment, the steam combined with HCl treatment decreased the mesopores, resulting in a remarkable decrease in catalyst stability.
出处
《太原理工大学学报》
CAS
北大核心
2012年第4期425-430,共6页
Journal of Taiyuan University of Technology
