Photocatalytic CO2‐to‐Syngas Evolution with Molecular Catalyst Metal‐Organic Framework Nanozymes

Abstract Syngas, a mixture of CO and H 2 , is a high‐priority intermediate for producing several commodity chemicals, e.g., ammonia, methanol, and synthetic hydrocarbon fuels. Accordingly, parallel sunlight‐driven catalytic conversion of CO 2 and protons to syngas is a key step toward a sustainable energy cycle. State‐of‐the‐art catalytic systems and materials often fall short as application‐oriented concurrent CO and H 2 evolution requires challenging reaction conditions which can hamper stability, selectivity, and efficiency. Here a light‐harvesting metal‐organic framework hosting two molecular catalysts is engineered to yield colloidal, water‐stable, versatile nanoreactors for photocatalytic syngas generation with highly controllable product ratios. In‐depth fluorescence, X‐ray, and microscopic studies paired with kinetic analysis show that the host delivers energy efficiently to active sites, conceptually yielding nanozymes. This unlocked sustained CO 2 reduction and H 2 evolution with benchmark turnover numbers and record incident photon conversions up to 36%, showcasing a highly active and durable all‐in‐one material toward application in solar energy‐driven syngas generation.