Mg的添加对Mo／ZSM－5催化剂催化甲烷芳构化性能的影响

 通过XRD，N2吸附和吡啶FT－IR等方法考察了Mg的添加对Mo／ZSM－5催化剂物化性质的影响．吡啶FT－IR结果表明，Mo－Mg／ZSM－5催化剂上Lewis酸中心与Br¨onsted酸中心的比值随着Mg添加量的增加而增大．在甲烷芳构化反应中，虽然催化剂上的积碳量随着Mg含量的增加而减少，但只有6％Mo－0．75％Mg／ZSM－5催化剂表现出比6％Mo／ZSM－5催化剂更好的稳定性，6％Mo－2％Mg／ZSM－5和6％Mo－3％Mg／ZSM－5两个催化剂的稳定性均比6％Mo／ZSM－5催化剂差．根据催化剂稳定性与酸性的关系提出，在有足够Br¨onsted酸中心存在的前提下，可以通过调变Lewis酸中心和Br¨onsted酸中心的比值来提高催化剂的稳定性．

Effect of Mg Addition on Catalytic Performance of Mo/ZSM-5 Catalyst for Methane Aromatization

The effect of Mg addition no the Mo/ZSM 5 catalyst was investigated by XRD, nitrogen adsorption and pyridine FT IR methods. The FT IR spectra of pyridine adsorbed on Mo Mg/ZSM 5 indicated that the ratio of Lewis acid sites to Brnsted acid sites on the catalyst samples increased with the increase of Mg loading. When Mo Mg/ZSM 5 was used in methane dehydro aromatization, the carbon deposition on the catalyst decreased with the increase of Mg loading, and only the stability of 6%Mo 0 75%Mg/ZSM 5 was higher than that of 6%Mo/ZSM 5. This illuminated that the catalyst stability can be enhanced by optimizing the ratio of Lewis acid sites to Brnsted acid sites with medium/strong strength in the presence of enough Brnsted acid sites.