Solid-state NMR study of the stability of MOR framework aluminum

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外文摘要：MOR zeolite has been effectively utilized for dimethyl ether(DME)carbonylation reaction due to its unique pore structure and acidity.During industrial production,the transformation of ammonium type MOR zeolite(NH4-MOR)into proton type MOR zeolite(H-MOR)causes inevitable dealumination.Therefore,understanding the influencing factors and dynamic evolution mechanism of zeolite dealumination is crucial.In this work,the sta-bility of framework aluminum was studied by X-ray diffraction(XRD),Fourier transform infrared(FT-IR)spec-troscopy,29Si,27Al,1H magic angle spinning nuclear magnetic resonance(MAS NMR),and DME carbonylation performance evaluation.These results indicate that extra-framework cation Na+and NH4+could better preserve the aluminum structure of the MOR zeolite framework compared to H+,primarily due to the different'attraction'of the framework to water.Furthermore,the impact of water on the zeolite framework aluminum at high tem-perature was studied by manipulating the humidity of the calcination atmosphere,revealing the formation of extra-framework six-coordinated aluminum(Al(Ⅵ)-EF)and the mechanism of water influence on the zeolite framework aluminum.

外文关键词：

H-MORSolid-state NMRH2OFramework aluminum stabilityDealumination

作者：

Xinzhi Ding、Chong Liu、Jing Niu、Nan Chen、Shutao Xu、Yingxu Wei、Zhongmin Liu

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作者单位：

National Engineering Research Center of Lower-Carbon Catalysis Technology,Dalian Institute of Chemical Physics,Chinese Academy of Sciences,Dalian 116023,China

University of Chinese Academy of Sciences,Beijing 100049,China

National Engineering Research Center of Lower-Carbon Catalysis Technology,Dalian Institute of Chemical Physics,Chinese Academy of Sciences,Dalian,116023,China

School of Chemistry,Dalian University of Technology,Dalian,116024,China

State Key Laboratory of Catalysis,Dalian Institute of Chemical Physics,Chinese Academy of Sciences,Dalian,116023,China

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出版年：

2024

DOI：

10.1016/j.cjsc.2024.100247

结构化学

中国化学会中国科学院福建物质结构研究所

结构化学

影响因子：0.44

ISSN：0254-5861

年,卷(期)：2024.43(4)