利用分子模拟技术研究不同分子筛催化1-辛烯裂解反应

以1-辛烯为原料，在HY、H 和HZSM-5分子筛上进行了催化裂解反应，结果表明，具有中孔结构和较多中强酸的ZSM-5分子筛具有较高的1-辛烯转化率和低碳烯烃选择性；1-辛烯在分子筛催化作用下除了发生裂解反应，还发生氢转移、环化等副反应。采用分子模拟技术对1-辛烯可能参与的不同类型反应进行了研究，发现HZSM-5分子筛孔径较小，且不含笼状结构，对1-辛烯的环化反应、氢转移反应等具有更强的过渡态约束作用，HY和Hβ分子筛由于孔径较大且具有笼状结构，对1-辛烯参与的不同反应选择性较差，从微观角度解释了1-辛烯在HZSM-5催化作用下具有较高转化率和小分子烯烃选择性的内在原因。

STUDY ON CATALYTIC PYROLYSIS OF 1-OCTENE OVER VARIOUS ZEOLITES USING MOLECULAR SIMULATION

Catalytic pyrolysis of 1-octene over HY, Hβ and HZSM-5 zeolites was investigated. Results showed that HZSM-5 zeolite having medium pore structure and certain amount of strong and medium acid sites exhibited good 1-octene conversion and high light olefins selectivity. Molecular simulation technique was used to study the types of reactions involved in the catalytic pyrolysis of 1-octene. It was found that as compared with HY and Hβ zeolites, the characteristic pore structure of HZSM-5 zeolite, such as smaller pore size and lack of cages, restricted the reactions of cyclization and hydrogen transfer to take place during the catalytic pyrolysis of 1-octene, thus the conversion of 1-octene and the selectivity to light olefins of HZSM-5 zeolite were high.