Methylcyclopentenyl cations(MCP+)have been regarded as active intermediates during methanol conversion,however,their function mode in the reaction are still uncertain.In our recent report,trimethylcyclopentenyl cation...Methylcyclopentenyl cations(MCP+)have been regarded as active intermediates during methanol conversion,however,their function mode in the reaction are still uncertain.In our recent report,trimethylcyclopentenyl cation(triMCP+)and its deprotonated counterpart(trimethylcyclopentadiene,tri MCP)were directly captured on H-RUB-50 catalyst with small cavity by the aid of in situ 13C MAS NMR spectroscopy,and their higher catalytic reactivity were clarified by 12C/13C-CH3OH isotopic switch experiment.In this contribution,an alternative route-cyclopentadienes-based cycle was applied on methanol conversion catalyzed on the H-RUB-50,in which ethene was produced with the participation of tri MCP+as critical intermediate.Then the cyclopentadienes-based cycle was predicted to be energetically favorable for ethene formation by density functional theory(DFT)calculations.The energetic comparison of paring mechanism in the aromatics-based cycle and cyclopentadienes-based cycle with the involvements of trimethylcyclopentadienyl(tri MCPdi+)and tri MCP+as the corresponding active intermediates suggests that cyclopentadienes-based cycle is a feasible route for ethene formation.Furthermore,this work highlights the importance of the steric constraint and the host-guest interaction induced by the zeolite with cavity structure in the formation of intermediates and reaction pathway.展开更多
基金the financial support from the National Natural Science Foundation of China(Nos.91745109,21703239 and 21972142)the Key Research Program of Frontier Sciences,CAS,Grant No.QYZDY-SSW-JSC024+2 种基金the Youth Innovation Promotion Association of the Chinese Academy of Sciences(No.2014165)the International Partnership Program of Chinese Academy of Sciences,Grant No.121421KYSB20180007Liaoning Revitalization Talents Program(XLYC1807227)。
文摘Methylcyclopentenyl cations(MCP+)have been regarded as active intermediates during methanol conversion,however,their function mode in the reaction are still uncertain.In our recent report,trimethylcyclopentenyl cation(triMCP+)and its deprotonated counterpart(trimethylcyclopentadiene,tri MCP)were directly captured on H-RUB-50 catalyst with small cavity by the aid of in situ 13C MAS NMR spectroscopy,and their higher catalytic reactivity were clarified by 12C/13C-CH3OH isotopic switch experiment.In this contribution,an alternative route-cyclopentadienes-based cycle was applied on methanol conversion catalyzed on the H-RUB-50,in which ethene was produced with the participation of tri MCP+as critical intermediate.Then the cyclopentadienes-based cycle was predicted to be energetically favorable for ethene formation by density functional theory(DFT)calculations.The energetic comparison of paring mechanism in the aromatics-based cycle and cyclopentadienes-based cycle with the involvements of trimethylcyclopentadienyl(tri MCPdi+)and tri MCP+as the corresponding active intermediates suggests that cyclopentadienes-based cycle is a feasible route for ethene formation.Furthermore,this work highlights the importance of the steric constraint and the host-guest interaction induced by the zeolite with cavity structure in the formation of intermediates and reaction pathway.
