甲烷无氧芳构化反应中钼基分子筛催化剂上积炭的表征

To find out the essence of the coke deactivation and probe into the way of elimination of the coke deactivation over zeolite catalysts in methane non-oxidative aromatization, the coke soluble or insoluble in CH2Cl2 was separated. Its composition and property were characterized by MS and IR methods. It was found that the soluble coke mainly consists of non-aromatic hydrocarbons. Its composition did not change with the reaction time, reaction temperature and acidity of the catalyst. The souble coke which was the precursor of the insoluble coke did not affect the activity of the catalysts. The souble coke formed mainly in the pores of zeolite catalysts. The insoluble coke consisted of the condensed-aromatics type hydrocarbon. Its composition changed with the reaction time, reaction temperature and acidity of the catalyst. The insoluble coke was divided into two types: burning mainly at 798 K and 843 K respectively. The insoluble coke of the two types with different H/C might be the main reason for the deactivation of catalysts.