Construction of the CoO/NbO Composite Catalyst with a Prickly Spherelike Architecture for CO Cycloaddition with Styrene Oxide.

A high-performance NbO-based catalyst for the cycloaddition of CO with SO is designed by properly unifying the concepts of compositional regulation and architectural engineering. The CoO/NbO composite catalyst shows an intriguing prickly spherelike morphology. It exhibits a high styrene carbonate (SC) yield of 94.3% within 4 h (0.0824 mol g h) under mild reaction conditions (0.4 MPa of CO and a reaction temperature of 90 °C) assisted by tetrabutylammonium bromide (TBAB). The coupling of CoO, which chemically interacts with NbO, can effectively modulate the electronic structures of NbO, constructing abundant acid/base sites for effectively activating the reactants and boosting the intrinsic activity. The high activity, cost-effectiveness, and good recyclability make the tailor-made CoO/NbO prickly spheres more appealing for commercial applications. This work offers new insights into designing and constructing well-integrated metal oxide composites for the cycloaddition of CO with an epoxide.