【摘要】 <正> HZSM-5分子筛已被广泛用作催化剂,其中之一是把甲醇转化成汽油及各种低级烯烃.甲醇分子在这种分子筛表面的吸附和转化机理已成为人们重视研究的问题. 本文作者曾用热脱附谱方法探测和讨论了HZSM-5表面酸性(包括种类和数目)、甲醇分子在表面的吸附位置和反应产物等现象,对催化机理作了一定的解释.限于篇幅,本文只讨论前两个问题.更多还原

【Abstract】 Thermal desorption spectra of ammonia and methanol on HZSM-5 zeolite were studied under ultra high va uum condition. In view of these spectra, a conclusion about the heterogeneity of this zeolite can be drawn. On HZSM-5 surface, there are mainly three kinds of acid sites, a,B,and y, they are different in acid property and density. These results are in agreement with the TPD experimental results. Methanol can only be adsorbed on the "B" type acid sites of HZSM-5 zeolite surface to form two different adsorption states, which correspond to the B and y acid sites in ammonia spectra.更多还原