Revisiting Photocatalytic CO2 Reduction to Methanol: A Perspective Focusing on Metal-Organic Frameworks.

Photocatalytic CO2 reduction to CH3OH, particularly with metal-organic frameworks (MOFs) as photocatalysts, has garnered significant attention due to its long-term potential to harness sunlight for converting CO2 into a valuable fuel and chemical feedstock. Numerous studies in the literature report the successful formation of CH3OH from photocatalytic CO2 reduction, sometimes supplemented with sacrificial agents, with claims substantiated by isotopic labelling measurements. However, in this Scientific Perspective, we note that much of the existing evidence has not been obtained under sufficiently rigorous experimental conditions to conclusively confirm the formation of a highly reactive product like CH3OH from the chemically stable CO2 molecule. This Scientific Perspective outlines best practices designed to provide robust evidence for CH3OH formation in photocatalytic processes, which could be instrumental in clarifying the state-of-the-art and accelerating the development of this technology toward practical applications.