不同方法制备的Mo/HZSM-5催化剂上甲烷的芳构化反应

 采用机械混合、机械混合后焙烧和机械混合后微波处理等方法制备Mo／HZSM－5催化剂，并对催化剂上甲烷芳构化反应性能进行了考察．结果表明，与浸渍法相比，用机械混合法、固相反应法和微波法制备的催化剂，在保持甲烷转化率不变的前提下，能明显提高芳烃选择性并减少积炭的生成；不同方法制备的Mo／HZSM－5催化剂上Mo物种的落位不同，机械混合法、固相反应法和微波法使Mo物种较多地落位于分子筛外表面．结合反应结果可以得出，落位于分子筛外表面的Mo物种对甲烷芳构化反应更为有利，而且明显减少积炭的生成．

Methane Dehydro-Aromatization over Mo/HZSM-5 Catalyst Prepared by Different Methods

Mo/HZSM 5 is a typical catalyst for methane dehydro aromatization in the absence of oxygen. The catalyst was prepared with impregnation method in previous studies. In this paper, mechanical mixing, solid reaction and microwave methods were used for Mo/HZSM 5 preparation. In addition, the catalytic performance of the catalyst for methane dehydro aromatization was investigated. Compared with impregnated Mo/HZSM 5 sample, the catalyst samples prepared with mechanical mixing, solid reaction and microwave methods show higher selectivity for aromatics and lower selectivity for coke. BET, XRD and NH 3 TPD experimental results exhibited that the location of Mo species is heavily dependent on the preparation method. It is suggested that the Mo species located on the external surface of the zeolite is more efficient for methane dehydro aromatization, and at the same time suppresses the coke formation.