Metalized Carbon Nitrides for Efficient Catalytic Functionalization of CO2

As an effective approach toward sustainability and global carbon balance, the reductive conversion of CO2 into value-added chemicals is of considerable significance. Here, by simply calcining the mixture of NH4SCN and KCl in an air atmosphere, potassium dopants and negatively charged electron-rich centers are simultaneously introduced into carbon nitride materials via a metalation engineering strategy. The resultant metalized catalysts with deprotonated imide sites and doped potassium ions demonstrate much-enhanced activity for catalyzing CO2 reductive hydrosilylation with excellent conversion and >90% selectivity, whereas the pristine carbon nitride catalyst shows only negligible activity. Both experimental and theoretical results reveal the crucial role of the negatively charged electron-rich centers and potassium dopants in tailoring the energy band positions and electronic structure for the efficient donor–acceptor interaction and much increased driving force for CO2 reduction. The present work offers molecular-level insights into the boosted CO2 reduction activity via engineering the electronic structure of the metalized carbon nitride catalyst and reducing the energy offset between frontier molecular orbitals of CO2 and the catalyst, which can provide a conceptual guide for further development of efficient catalytic CO2 reduction systems.