Novel and Highly Efficient Conversion of Carbon Dioxide to Cyclic Carbonates Using Benzotriazolium Ionic Liquid-Modified Periodic Mesoporous Organosilica as a Heterogeneous and Recyclable Nanocatalyst

In the present study, we demonstrated the synthesis of copper oxychloride anionic benzotriazolium ionic liquid-modified periodic mesoporous organosilica PMO@ILCu 2 (OH) 3 Cl 2 (x) as efficient and green retrievable heterogeneous nanocatalysts for the synthesis of cyclic carbonates via cycloaddition of CO 2 with epoxides. Compared to other nanocatalysts, a superior catalytic activity was observed with PMO@ILCu 2 (OH) 3 Cl 2 (1.0), giving excellent yields and selectivities under solvent- and cocatalyst-free conditions. We also found that the existence of intensification synergistic effects from the hydroxyl groups sites of periodic mesoporous organosilica and the active sites of the functionalized ionic liquid, resulting in the enhanced catalytic activity. The catalytic process displayed ease of recovery, excellent stability and recyclability for at least five runs without significant loss of its catalytic activity. The developed catalytic system is proven to be a powerful tool for the chemical fixation of CO 2 with epoxides to produce the cyclic carbonates. Graphical abstract An efficient protocol is described for producing cyclic carbonates in excellent yields and selectivities under cocatalyst- and solvent-free conditions by treating epoxides with carbon dioxide, promoted by copper oxychloride anionic benzotriazolium ionic liquid-modified periodic mesoporous organosilica.