At the invitation of Accounts of Chemical Research, Deng group from Wuhan Institute of Physics and Mathematics recently published an account entitled as “Acidic Properties and Structure–Activity Correlations of Solid Acid Catalysts Revealed by Solid-State NMR Spectroscopy” (Acc. Chem. Res. 2016, 49:655-663). This review article covered the most recent research work in the field of solid-state NMR studies of solid acid catalysts.
Solid acid catalysts with tunable structural and acidic properties are promising heterogeneous catalysts for manipulating the activity and selectivity of industrially important catalytic reactions. The performances of acid-catalyzed reactions are mostly dictated by the acidic features such as type, amount, strength, and local environment of acid sites. The acidic property of solid acid catalysts may strongly affect the host–guest interactions, reaction mechanism, and shape selectivity of the heterogeneous catalytic system. In this account, solid state NMR spectroscopy in conjunction with theoretical calculations is a promising and powerful tool capable of providing quantitative description of catalytic active sites, reaction pathway, and relevant structure–activity correlations on the local surfaces of solid acid catalysts, thus promoting our fundamental understanding of the reaction mechanism involved during heterogeneous catalysis at the molecular level. Relevant discussions focus primarily on results obtained from Deng research group in the past decade, including (i) quantitative and qualitative acidity characterization utilizing probe molecules, (ii) probing the spatial proximity and synergy effect of acid sites, and (iii) influence of acid features and pore confinement effect on catalytic activity, transition-state stability, reaction pathway, and product selectivity of solid acid catalysts such as zeolites, metal oxides, and heteropolyacids. The obtained information can provide insights toward our understanding in heterogeneous catalysis, especially the roles of structural and acidic properties on catalytic performances and reaction mechanism of acid-catalyzed systems, which should be beneficial for rational design of solid acid catalysts.
This work is supported from the National Natural Science Foundation and the Chinese Academy of Sciences.