Methanol to hydrocarbons reaction over H beta zeolites studied by high resolution solid-state NMR spectroscopy: Carbenium ions formation and reaction mechanism
文献类型:期刊论文
作者 | Zhang, Mozhi1,5; Xu, Shutao1; Li, Jinzhe1; Wei, Yingxu1; Gong, Yanjun2; Chu, Yueying3; Zheng, Anmin3; Wang, Jinbang1,5; Zhang, Wenna1,5; Wu, Xinqiang1,5 |
刊名 | JOURNAL OF CATALYSIS
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出版日期 | 2016-03-01 |
卷号 | 335页码:47-57 |
关键词 | Methanol-to-hydrocarbons C-13 MAS NMR Carbenium ions Methylcyclopentenyl cations Heptamethylbenzenium cation |
英文摘要 | Carbenium ions as active intermediates play very important roles in methanol conversion to hydrocarbons (MTH) reactions, while their observation and structure confirmation is of great difficulty. In this contribution, solid-state magic-angle-spinning (MAS) NMR spectroscopy has been applied in the investigation of methanol conversions over H beta zeolite. By attempting the batch-like and continuous-flow reactions over the catalysts with varied acid site densities and under the condition of different reaction temperatures and atmosphere pressures, an optimized way for direct observation of carbenium ions has been developed. For the first time, two types of carbenium ions, including methylcyclopentenyl (MCP+) cations and heptamethylbenzenium (heptaMB(+)) cation, have been successfully captured by C-13 MAS NMR during methanol conversion over H beta zeolite. For the batch-like reactions, methanol conversion and carbenium ions observation have been promoted by using the Hp catalysts with more Bronsted acid sites and performing the reaction under relatively high atmosphere pressure. The competitive adsorption from reactants and products on the catalyst surface may cause the deprotonation of the carbenium ions. In the continuous-flow reactions, both the heptaMB(+) and MCP+ cations are formed and more easily observed compared with batch-like reactions due to the improved methanol conversion and the reduced competitive adsorption on the Bronsted acid sites. Based on the carbenium ions identification, a catalytic cycle is proposed to explain the generation of isobutene, a predominantly generated product on Hp zeolite, during methanol conversion. (C) 2015 Elsevier Inc. All rights reserved. |
WOS标题词 | Science & Technology ; Physical Sciences ; Technology |
类目[WOS] | Chemistry, Physical ; Engineering, Chemical |
研究领域[WOS] | Chemistry ; Engineering |
关键词[WOS] | SURFACE METHOXY GROUPS ; TO-OLEFINS CONVERSION ; IN-SITU NMR ; STABLE CARBOCATIONS ; MAS NMR ; HEPTAMETHYLBENZENIUM CATION ; CYCLOPENTENYL CATIONS ; CATALYTIC CYCLE ; ACIDIC ZEOLITES ; POOL MECHANISM |
收录类别 | SCI |
语种 | 英语 |
WOS记录号 | WOS:000371098200005 |
公开日期 | 2016-04-26 |
源URL | [http://ir.wipm.ac.cn/handle/112942/9198] ![]() |
专题 | 武汉物理与数学研究所_磁共振应用研究部 |
作者单位 | 1.Chinese Acad Sci, Dalian Inst Chem Phys, iChEM Collaborat Innovat Ctr Chem Energy Mat, Natl Engn Lab Methanol Olefins,Dalian Natl Lab Cl, Dalian 116023, Peoples R China 2.China Univ Petr, CNPC Key Lab Catalysis, State Key Lab Heavy Oil Proc, Beijing 102249, Peoples R China 3.Chinese Acad Sci, Wuhan Inst Phys & Math, State Key Lab Magnet Resonance & Atom & Mol Phys, Natl Ctr Magnet Resonance Wuhan, Wuhan 430071, Peoples R China 4.Chinese Acad Sci, Dalian Inst Chem Phys, State Key Lab Catalysis, Dalian 116023, Peoples R China 5.Univ Chinese Acad Sci, Beijing 100039, Peoples R China |
推荐引用方式 GB/T 7714 | Zhang, Mozhi,Xu, Shutao,Li, Jinzhe,et al. Methanol to hydrocarbons reaction over H beta zeolites studied by high resolution solid-state NMR spectroscopy: Carbenium ions formation and reaction mechanism[J]. JOURNAL OF CATALYSIS,2016,335:47-57. |
APA | Zhang, Mozhi.,Xu, Shutao.,Li, Jinzhe.,Wei, Yingxu.,Gong, Yanjun.,...&Liu, Zhongmin.(2016).Methanol to hydrocarbons reaction over H beta zeolites studied by high resolution solid-state NMR spectroscopy: Carbenium ions formation and reaction mechanism.JOURNAL OF CATALYSIS,335,47-57. |
MLA | Zhang, Mozhi,et al."Methanol to hydrocarbons reaction over H beta zeolites studied by high resolution solid-state NMR spectroscopy: Carbenium ions formation and reaction mechanism".JOURNAL OF CATALYSIS 335(2016):47-57. |
入库方式: OAI收割
来源:武汉物理与数学研究所
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