title: Experimental Evidence on the Formation of Ethene through Carbocations in Methanol Conversion over H-ZSM-5 Zeolite.
abstract: The methanol to olefins conversion over zeolite catalysts is a commercialized process to produce light olefins like ethene and propene but its mechanism is not well understood. We herein investigated the formation of ethene in the methanol to olefins reaction over the H-ZSM-5 zeolite. Three types of ethylcyclopentenyl carbocations, that is, the 1-methyl-3-ethylcyclopentenyl, the 1,4-dimethyl-3-ethylcyclopentenyl, and the 1,5-dimethyl-3-ethylcyclopentenyl cation were unambiguously identified under working conditions by both solid-state and liquid-state NMR spectroscopy as well as GC-MS analysis. These carbocations were found to be well correlated to ethene and lower methylbenzenes (xylene and trimethylbenzene). An aromatics-based paring route provides rationale for the transformation of lower methylbenzenes to ethene through ethylcyclopentenyl cations as the key hydrocarbon-pool intermediates.
authors.affiliation: National Center for Magnetic Resonance in Wuhan, State Key Laboratory Magnetic Resonance and Atomic and Molecular Physics, Wuhan Institute of Physics and Mathmatics, Chinese Academy of Sciences, Wuhan 430071 (P.R. China).
authors.forename: Chao
authors.initials: C
authors.lastname: Wang
authors.affiliation: National Center for Magnetic Resonance in Wuhan, State Key Laboratory Magnetic Resonance and Atomic and Molecular Physics, Wuhan Institute of Physics and Mathmatics, Chinese Academy of Sciences, Wuhan 430071 (P.R. China).
authors.forename: Xianfeng
authors.initials: X
authors.lastname: Yi
authors.affiliation: National Center for Magnetic Resonance in Wuhan, State Key Laboratory Magnetic Resonance and Atomic and Molecular Physics, Wuhan Institute of Physics and Mathmatics, Chinese Academy of Sciences, Wuhan 430071 (P.R. China). xujun@wipm.ac.cn.
authors.forename: Jun
authors.initials: J
authors.lastname: Xu
authors.affiliation: National Center for Magnetic Resonance in Wuhan, State Key Laboratory Magnetic Resonance and Atomic and Molecular Physics, Wuhan Institute of Physics and Mathmatics, Chinese Academy of Sciences, Wuhan 430071 (P.R. China).
authors.forename: Guodong
authors.initials: G
authors.lastname: Qi
authors.affiliation: National Center for Magnetic Resonance in Wuhan, State Key Laboratory Magnetic Resonance and Atomic and Molecular Physics, Wuhan Institute of Physics and Mathmatics, Chinese Academy of Sciences, Wuhan 430071 (P.R. China).
authors.forename: Pan
authors.initials: P
authors.lastname: Gao
authors.affiliation: National Center for Magnetic Resonance in Wuhan, State Key Laboratory Magnetic Resonance and Atomic and Molecular Physics, Wuhan Institute of Physics and Mathmatics, Chinese Academy of Sciences, Wuhan 430071 (P.R. China).
authors.forename: Weiyu
authors.initials: W
authors.lastname: Wang
authors.affiliation: National Center for Magnetic Resonance in Wuhan, State Key Laboratory Magnetic Resonance and Atomic and Molecular Physics, Wuhan Institute of Physics and Mathmatics, Chinese Academy of Sciences, Wuhan 430071 (P.R. China).
authors.forename: Yueying
authors.initials: Y
authors.lastname: Chu
authors.affiliation: National Center for Magnetic Resonance in Wuhan, State Key Laboratory Magnetic Resonance and Atomic and Molecular Physics, Wuhan Institute of Physics and Mathmatics, Chinese Academy of Sciences, Wuhan 430071 (P.R. China).
authors.forename: Qiang
authors.initials: Q
authors.lastname: Wang
authors.affiliation: National Center for Magnetic Resonance in Wuhan, State Key Laboratory Magnetic Resonance and Atomic and Molecular Physics, Wuhan Institute of Physics and Mathmatics, Chinese Academy of Sciences, Wuhan 430071 (P.R. China).
authors.forename: Ningdong
authors.initials: N
authors.lastname: Feng
authors.affiliation: National Center for Magnetic Resonance in Wuhan, State Key Laboratory Magnetic Resonance and Atomic and Molecular Physics, Wuhan Institute of Physics and Mathmatics, Chinese Academy of Sciences, Wuhan 430071 (P.R. China).
authors.forename: Xiaolong
authors.initials: X
authors.lastname: Liu
authors.affiliation: National Center for Magnetic Resonance in Wuhan, State Key Laboratory Magnetic Resonance and Atomic and Molecular Physics, Wuhan Institute of Physics and Mathmatics, Chinese Academy of Sciences, Wuhan 430071 (P.R. China).
authors.forename: Anmin
authors.initials: A
authors.lastname: Zheng
authors.affiliation: National Center for Magnetic Resonance in Wuhan, State Key Laboratory Magnetic Resonance and Atomic and Molecular Physics, Wuhan Institute of Physics and Mathmatics, Chinese Academy of Sciences, Wuhan 430071 (P.R. China). dengf@wipm.ac.cn.
authors.forename: Feng
authors.initials: F
authors.lastname: Deng
keywords: carbocations; olefins; reaction mechanisms; solid-state NMR spectroscopy; zeolites