摘要
以密度泛函理论(DFT)为基础,通过对丁烯-1骨架异构单分子机理反应过程的模拟研究发现,丁烯-1很难在新鲜分子筛催化剂的酸性位上通过单分子反应生成异丁烯,而是以分子筛催化剂酸性位上无法化学脱附的碳正离子为新的活性位,进行第2次反应,生成异丁烯。因为该种反应方式可以使速控步骤的能垒大幅降低,有利于提高异丁烯的选择性。因此,有效地利用第1次反应的吸附物种,引发后续的烯烃骨架异构化反应,对新型分子筛催化剂的设计十分重要。
The reaction pathway of skeletal isomerization of butene-1 via monomolecular mechanism was studied by density functional theory calculations. The results indicated that isobutene was difficult to be formed via monomolecular mechanism over the acidic sites of fresh zeolite, but the undesorbed primary carbenium ions could act as the new active sites to initiate the secondary reaction, resulting in higher selectivity of isobutene. It could be ascribed to the great decrease of energy barrier for the rate-determining step of butene-1 skeletal isomerization. Therefore, for the design of the new zeolite catalysts, it was important to make best use of the undesorbed primary carbenium ions to promote the following olefin skeletal isomerization.
出处
《石油学报（石油加工）》
EI
CAS
CSCD
北大核心
2013年第2期186-190,共5页
Acta Petrolei Sinica(Petroleum Processing Section)
基金
中国石化丁烯异构制异丁烯的技术开发项目(ST12025)
中国石化从液化气生产高辛烷值汽油和芳烃的技术研究项目(110017)资助
关键词
丁烯-1
骨架异构
过渡态
单分子机理
能垒
butene-1
skeletal isomerization
transition state
monomolecular mechanism
energy barrier
