The role of C1 species in the methanol-to-hydrocarbons reaction:Beyond merely being reactants  

C1物种在甲醇制烃类反应过程中的作用:超越反应物角色

作　　者：Yanan Zhang Wenna Zhang Chengwei Zhang Linhai He Shanfan Lin Shutao Xu Yingxu Wei Zhongmin Liu 张亚楠;张雯娜;张成伟;何林海;林杉帆;徐舒涛;魏迎旭;刘中民(中国科学院大连化学物理研究所,低碳催化技术国家工程研究中心,洁净能源国家实验室,能源材料化学协同创新中心,辽宁大连116023;中国科学院大连化学物理研究所,催化基础国家重点实验室,辽宁大连116023;中国科学院大学,北京100049)

机构地区：[1]National Engineering Research Center of Lower-Carbon Catalysis Technology,Dalian National Laboratory for Clean Energy,iChEM(Collaborative Innovation Center of Chemistry for Energy Materials),Dalian Institute of Chemical Physics,Chinese Academy of Sciences,Dalian 116023,Liaoning,China [2]State Key Laboratory of Catalysis,Dalian Institute of Chemical Physics,Chinese Academy of Sciences,Dalian 116023,Liaoning,China [3]University of Chinese Academy of Sciences,Beijing 100049,China

出　　处：《Chinese Journal of Catalysis》2025年第4期169-178,共10页催化学报(英文)

基　　金：国家重点研发计划(2021YFA1502600);国家自然科学基金(22372169,22002157,22402190,21991092,21991090,22288101);辽宁省自然科学基金(2022-BS-019).

摘　　要：In the methanol-to-hydrocarbons(MTH)process,C1 species,including methanol,dimethyl ether,and surface methoxy species(SMS),play crucial roles in the evolution of organic species and the construction of reaction networks.Understanding the roles of C1 species throughout the entire MTH process is both essential and challenging.Herein,the dynamic evolution of organic species and unique variation of C1 species during the real-time MTH process were observed by operando diffused reflectance Fourier transform infrared spectroscopy and ex-situ 13C cross polarization/magic-angle spinning nuclear magnetic resonance experiments.Importantly,density functional theory calculations thoroughly illustrated that methanol and SMS serve as key C1 species,in the form of not only methylation agents but also hydride acceptors,and their contributions vary across different reaction periods.Initially,SMS acts as the preferential C1 surface intermediate,methylating with hydrocarbons to propagate C–C bond,while also accepting hydrides to generate precursors for active hydrocarbon pool species.As reaction progresses,the role of SMS gradually diminishes,and thereby methanol becomes the predominant C1 species,in methylation for efficient product formation,meanwhile in hydride-transfer causing catalyst deactivation.Additionally,it was demonstrated that the confined zeolite microenvironment modified by large organics affects methanol adsorption and SMS formation,also accounting for the absence of SMS during the later period of reaction.This work provides a comprehensive and systematic understanding of the dynamic roles of C1 species throughout the MTH process,beyond the role as reactants.作为非石油资源生产包括低碳烯烃、芳烃、汽油等烃类物质的工业化路线,甲醇制烃类(MTH)反应受到学术界和工业界的广泛关注.在MTH反应过程中,C1物种,包括甲醇、二甲醚和表面甲氧基物种,在反应有机物种的演变和复杂反应网络的构建中起着至关重要的作用.C1物种不仅作为反应物,而且还与活性烃池物种协同作用,为自催化过程提供“燃料”并主导自催化动态演变.然而,在MTH复杂反应体系中,甲醇、二甲醚、甲氧基等多种C1物种与活性烃池物种和非活性稠环芳烃物种相互作用机制以及随着反应过程的演变规律尚不明确.因此,深入理解C1物种在整个MTH反应过程中的重要作用是必要且具挑战的.本文借助理论计算及谱学实验深入探究了C1物种在整个MTH复杂反应过程中的动态作用,不仅仅是作为C1反应物的作用.首先,开展了原位漫反射傅立叶变换红外光谱和外原位13C交叉极化魔角旋转核磁共振等谱学实验,分析了真实MTH反应过程中反应有机物种的动态演变和多种C1物种的独特变化.值得注意的是,不同C1物种信号(尤其是甲醇和甲氧基)的演化随MTH反应进行存在差异,这表明其与不同反应阶段存留有机物种的相互作用有所不同.进一步借助密度泛函理论计算详细地揭示了甲醇和甲氧基这两种关键的C1物种,作为甲基化试剂参与甲基化反应以及作为氢受体促进不饱和物种生成反应中的作用,阐述了它们在MTH不同反应阶段的具体贡献差异.在反应初始阶段,甲氧基作为主导的C1表面物种,与烃类物种发生甲基化反应参与C–C键的生成及碳链增长,同时也作为氢受体促进活性烃池物种形成.随着反应进行,甲氧基发挥的作用逐渐减弱,甲醇取而代之成为优势的C1物种,参与高效期甲基化反应以生成低碳烯烃产物,同时参与氢转移反应进一步导致催化剂积碳失活.此外,研究表明反应后�

关 键 词：METHANOL-TO-HYDROCARBONS C1 species Methylation Hydride-transfer Confined zeolite microenvironments SAPO-34 

分 类 号：O643.3[理学—物理化学]