沸石载体结构对甲烷无氧芳构化性能的影响

Effects of Zeolite Structure on the Catalytic Performance of Catalysts for Methane Non oxidative Aromatization

考察了担载ＭｏＯ３的沸石催化剂上甲烷的无氧芳构化性能，并与沸石结构相关联．结果表明，孔径与苯分子动态直径相当的ＺＳＭ－５、ＺＳＭ－８、ＺＳＭ－１１和β沸石等是甲烷无氧芳构化催化剂的良好载体，其中３％ＭｏＯ３／ＨＺＳＭ－１１具有最高的甲烷芳构化活性和稳定性，９７３Ｋ下的转化率和苯选择性分别为８．０％和９０．９％；６％ＭｏＯ３／ＨＺＳＭ－８与７％ＭｏＯ３／Ｈ－β芳构化性能相当．以ＨＭＣＭ－４１和ＨＳＡＰＯ－３４为载体时芳构化活性很低，以ＨＭＯＲ、ＨＸ和ＨＹ为载体时仅有少量乙烯生成，而以ＨＳＡＰＯ－５和ＨＳＡＰＯ－１１为载体时未检测到烃类生成．

The catalytic performance for methane aromatization in the absence of oxygen over various supported zeolite catalysts was studied on a continuous flow fixed bed reactor. It is found that H form silica alumina zeolites with two dimensional space structure, such as ZSM 5, ZSM 8 and ZSM 11 whose pore size is very near to the dynamic diameter of benzene (0 6 nm), are fine supports for methane aromatization, among which 3%MoO 3/HZSM 11 possesed the highest activity and stability, the maximum conversion of methane and selectivity to benzene are 8 0% and 90 9% respectively. The catalytic performance of MoO 3/HZSM 8 and 3%MoO 3/H β are relatively lower than that of 3%MoO 3/ HZSM 5. The catalysts supported on HMCM 41 and HSAPO 34 have a very low activity for the reaction and over the catalysts of MoO 3/HMOR, HX and HY only a small amount of ethylene is produced, while hydrocarbons have not been detected over the catalysts of MoO 3/HSAPO 5 and MoO 3/HSAPO 11.