摘要
用XRD,ESR,Mossbauer谱,TPD,IR及连续反应等技术,考察了水热处理对杂原子(Fe)ZSM-5的结构稳定性、表面酸性和对甲醇转化为低碳烯烃反应性能的影响。在水蒸汽的影响下,骨架铁易向分子筛表面迁移而使分子筛骨架向silicalite-1转化。(Fe)ZSM-5的表面酸性明显弱于(Al)ZSM-5,而且酸中心以L酸为主,随着水热处理温度的提高,B酸下降程度大于L酸。另外,随着水热处理温度的提高,甲醇转化的活性降低。
The structure stability, surface acidity end catalytic activity for the conversion of metbanol of heterop.tom (Fe) ZSM-5 catalyst treated with steam were studied by TPD,ESR, IR, XRD, Mossbauer spectrum and catalytic conversion of meihanol. It was found that under the influence of steam the ferroatoms in the zeolite framework migrated ep.sily to the surface, leading to the zeolite framework converted to silicalite.The surface acidity of (Fe)ZSM-5 was obviously weaker than that of (ADZSM-5, and the acid sites were mainly of Le.vis acid. With, increasing the steam treatment temperature, the reduction of Bronsted acid was larger tbar that of Lewis acid and the catalytic activity for metbanol conversion decreased.
关键词
杂原子分子筛
甲醇
低碳烯烃
Hetoroatom zeolite,ZSM-5,methanol conversion,light olefins
