A TiO2‐Co(terpyridine)2 Photocatalyst for the Selective Oxidation of Cellulose to Formate Coupled to the Reduction of CO2 to Syngas

Immobilization of a phosphonated cobalt bis(terpyridine) catalyst on TiO2 nanoparticles generates a photocatalyst that allows coupling aqueous CO2‐to‐syngas (CO and H2) reduction to selective oxidation of biomass‐derived oxygenates or cellulose to formate. An enzymatic saccharification pre‐treatment process is employed that enables the use of insoluble cellulose as an electron‐donating substrate under benign aqueous conditions suitable for photocatalytic CO2 conversion. The hybrid photocatalyst consists of solely earth‐abundant components, and its heterogeneous nature allows for reuse and operation in aqueous solution for several days at 25 °C, reaching a cellulose‐to‐formate conversion yield of 17 %. Thus, the proof‐of‐concept for valorizing two waste streams (CO2 and biomass) simultaneously into value‐added chemicals through solar‐driven catalysis is demonstrated.