Roles of Cocatalysts in Biomass Photo(electro)refining

Abstract Photosynthesis converts solar energy, carbon dioxide, and water into biomass, offering a renewable energy and chemical source. Biomass photo(electro)refining (BPeR) emerges as a sustainable alternative to petrochemicals for fuel and chemical production. However, BPeR faces challenges due to photocatalyst limitations, necessitating the integration of cocatalysts. Cocatalysts significantly impact the efficiency, selectivity, and durability of BPeR reactions, yet their roles require systematic elucidation and understanding. This review explores how cocatalysts impact the carbon bond functionalization, cleavage, and formation in biomass and its derivatives. It discusses their crucial roles in charge carrier generation, separation, and transportation, particularly in catalyzing surface reactions such as hydrogen‐involved reactions, generation, and manipulation of oxygen or carbon radicals, and the C─C/O/H bond transformations. Additionally, it outlines challenges and prospects for developing cocatalysts to enhance BPeR efficiency and durability, boosting the viability of biomass as a sustainable source of energy and materials.