Visible‐Light‐Driven Furfural Oxidation over CuOx/Nb2O5

Abstract Maleic anhydride (MA) is an important polyester monomer that can be produced from oxidizing renewable furfural derived from biomass. However, MA generation from furfural requires harsh reaction conditions, and suffers from low efficiency and solvent corrosion. Herein, we design a Nb 2 O 5 photocatalyst loaded of highly dispersed CuO x (CuO x /Nb 2 O 5 ), which selectively catalyzes furfural oxidation to MA and the precursor (5‐hydroxy‐2(5 H )‐furanone, HF). Due to CuO x loading and forming a complex of ligand to metal charge transfer (LMCT) between the Nb 2 O 5 surface and adsorbed furfural, the CuO x /Nb 2 O 5 absorbs visible light to activate furfural though Nb 2 O 5 has a large band‐gap energy (3.2 eV). Singlet oxygen ( 1 O 2 ) is the key active species for C−C bond cleavage and CO generation. MA and HF is produced with a combined yield of 59 % under optimized conditions. This work provides a mild way to provide renewable maleic anhydride via oxidative C−C bond cleavage.