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.