Photocatalytic CO2 reduction integrated with biomass selective oxidation via single-atom Ru and P dual sites on carbon nitride

Abstract

Photocatalytic biorefinery integrated with CO2 reduction to co-produce value-added chemicals and fuels is significant but challenging. Herein, a novel photocatalyst with dual active sites is constructed, in which Ru single atoms coordinated with N2O2 on phosphorus-doped carbon nitride (Ru1N2O2@PCNx) via a pre-assembled pyrolysis strategy. Ru1N2O2@PCN1.0 catalyst exhibits an exceptional performance in both CO2 reduction and biorefinery processes, originating from the high photon-to-electron conversion rate. It achieves an extraordinary CO2 reduction and biorefinery, with 100.1 μmol g−1 h−1 evolution of CO and 91.2% yield of lactic acid. Furthermore, the as-prepared Ru1N2O2@PCN1.0 is successfully used in biomass-derived monosaccharides and xylan systems, validating the universality for broad applications. Experimental and theoretical analysis indicates that doping P in CN by replacing a corner C atom facilitates charge transfer/separation. Additionally, the introduction of Ru-N2O2 coordination regulates the electronic structure of CN and reduces the reaction energy barrier.