In-situ restructuring of Ni-based metal organic frameworks for photocatalytic CO₂ hydrogenation

As the global quest for sustainable energy keeps rising, exploring novel efficient and practical photocatalysts remains a research and industrial urge. Particularly, metal organic frameworks were proven to contribute to various stages of the carbon cycle, from CO₂ capture to its conversion. Herein, we report the photo-methanation activity of three isostructural, nickel-based metal organic frameworks incorporating additional niobium, iron, and aluminum sites, having demonstrated exceptional CO₂ capture abilities from thin air in previous reports. The niobium version exhibits the highest performance, with a CO₂ to CH₄ conversion rate in the order of 750–7500 µmol*gcatalyst⁻¹*h⁻¹ between 180°C and 240°C, achieving 97% selectivity under light irradiation and atmospheric pressure. The in-depth characterization of this framework before and after catalysis reveals the occurrence of an in-situ restructuring process, whereas active surface species are formed under photocatalytic conditions, thus providing comprehensive structure-performance correlations for the development of efficient CO₂ conversion photocatalysts.