Enhanced conversion of carbon dioxide (CO2) for cycloaddition with epoxide derivatives is highly desired in organic synthesis and green chemistry, yet it is still a challenge to obtain satisfactory activity under mild reaction conditions of temperature and pressure. For this purpose, an unexploited strategy is proposed here by incorporating near-infrared (NIR) photothermal properties into multicomponent catalysts. Through the electrostatic adsorption of Co- or Ce-substituted polyoxometalate (POM) clusters on the surface of graphene oxide (GO) with covalently grafted polyethyleneimine (PEI), a series of composite catalysts POMs@GO-PEI are prepared. The structural and property characterizations demonstrate the synergistic advantages of the catalysts bearing Lewis acids and bases and local NIR photothermal heating from the GO matrix for dramatically enhanced CO2 cycloaddition. Noticeably, while the turnover frequency increases up to 2718 h-1, the heterogeneous catalysts exhibit photothermal stability and recyclability. With this method, the onsite NIR photothermal transformation becomes extendable to more green reaction processes.
Keywords: carbon dioxide fixation; mild condition; near-infrared; photothermal catalysis; polyoxometalate.