Boron and Phosphorus Co-Doped Graphitic Carbon Nitride Cooperate with Bu4NBr as Binary Heterogeneous Catalysts for the Cycloaddition of CO2 to Epoxides

The development of a cost-effective heterogeneous catalytic system for the cycloaddition reaction of CO2 and epoxides is of great importance. In this manuscript, three kinds of boron and phosphorus co-doping graphitic carbon nitride (BP-CN) were prepared and characterized. Among them, BP-CN-1 displayed the optimal catalytic performance in the presence of Bu4NBr (tetrabutylammonium bromide) for the CO2 cycloaddition with propylene oxide, and 95% propylene carbonate yield was obtained under a 120 °C, 2 MPa, 6 h condition. Moreover, the BP-CN-1/Bu4NBr catalytic system is compatible with various epoxides and also exhibits excellent recycling performance under metal- and solvent-free conditions. Hence, BP-CN-1 exhibited an attractive application for the efficient fixation of CO2 due to the simple, eco-friendly synthesis route and effective catalytic activity.