五配位铝强化硅铝固体酸的固体核磁共振研究  

Solid-State NMR Spectroscopy Studies of Enhanced Acidity of Silica-Aluminas Based on Penta-Coordinated Aluminum Species

作　　者：王子春 黄骏 姜怡娇 WANG Zi-chun;HUANG Jun;JIANG Yi-jiao(School of Engineering,Macquarie University,Sydney,New South Wales 2109,Australia;Laboratory for Catalysis Engineering,School of Chemical and Biomolecular Engineering&Sydney Nano Institute,The University of Sydney,Sydney,NSW 2006,Australia)

机构地区：[1]School of Engineering,Macquarie University,Sydney,New South Wales 2109 [2]Laboratory for Catalysis Engineering,School of Chemical and Biomolecular Engineering&Sydney Nano Institute,The University of Sydney,Sydney,NSW 2006

出　　处：《波谱学杂志》2021年第4期552-570,共19页Chinese Journal of Magnetic Resonance

基　　金：Australian Research Council Discovery Projects(DP150103842,DP180104010,DE190101618).

摘　　要：Brønsted酸(B酸)是无定型硅铝(ASAs)表面最重要的催化活性位点.通常认为B酸位的形成只依赖于不饱和四配位铝(AlIV),且仅具有弱B酸性.通过合成五配位铝(AlV)富集的ASAs能够大幅提升高铝硅比(Al/Si)时的B酸含量及强度,克服传统AlIV富集的ASAs的酸性强化瓶颈.本文介绍了AlV在ASAs酸性强化及合成单原子催化剂中的重要作用.通过采用多种二维固体核磁共振(SSNMR)及原位质子NMR技术,证明了AlV能够大量富集在ASAs表面,着重介绍了两种基于AlV的新B酸位的形成机制,并阐明了AlV诱导单原子催化剂在ASAs表面形成的机理.Brønsted acid sites(BASs)on amorphous silica-aluminas(ASAs)are key active sites that can be generated based on tetra-coordinated aluminum(AlIV)species,albeit much weaker than that of zeolites.Penta-coordinated aluminum(AlV)species are recently reported to enhance the acidity of ASAs,and to overcome the limitations of AlIV species.This review introduces novel strategies to control the synthesis of AlV-enriched ASAs using flame spray pyrolysis(FSP)techniques.The acidic properties and local structure of AlV-enriched ASAs were characterized by various advanced 2D solid-state nuclear magnetic resonance(SSNMR)techniques and in situ 1H MAS NMR experiments,showing two new types of BASs from moderate to zeolitic acid strength based on AlV species.27Al and 1H MAS NMR studies uncovered the role of AlV species in tailoring single-atom catalysts on ASAs.

关 键 词：固体核磁共振(SSNMR) 无定型硅铝固体酸催化剂 五配位铝 结构-酸性关系 固体酸催化 

分 类 号：O482.53[理学—固体物理]