Zwitterionic Imidazole‐Urea Derivative Framework Bridged Mesoporous Hybrid Silica: A Highly Efficient Heterogeneous Nanocatalyst for Carbon Dioxide Conversion.

Abstract: The use of supported zwitterionic nanoparticles is an interesting and important strategy for the development of new CO2 conversion catalysts with enhanced activity and selectivity. Several zwitterionic imidazole‐urea derivative frameworks bridged mesoporous hybrid silica materials were prepared and characterized by using FTIR spectroscopy, solid‐state NMR spectroscopy, X‐ray photoelectron spectroscopy, XRD, TEM, and thermogravimetric analysis. The new Im‐Si‐X‐ϕ materials possess a high surface area, hydrogen‐bond donor ability, and nucleophilicity. The material that contains iodine and is protonated by an inorganic acid shows an excellent catalytic activity for CO2 conversion into cyclic carbonates with good recyclability. Reaction parameters for the cycloaddition of CO2 with propylene oxide to propylene carbonate were optimized. The one‐component material is an efficient heterogeneous catalyst for CO2 cycloaddition reactions and is a greener alternative to conventional supported transition‐metal catalysts. Its catalytic features were also compared to those of the unsupported free ionic compound and other supported catalysts reported previously. [ABSTRACT FROM AUTHOR]