摘要
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 。
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.
出处
《催化学报》
SCIE
CAS
CSCD
北大核心
2004年第1期70-74,共5页
关键词
钼
ZSM—5分子筛
镁
改性
甲烷
芳构化
molybdenum, ZSM 5 zeolite, magnesium, modification, methane, aromatization
