Selective Light‐Driven CO₂ to CO Reduction by a [FeFe]‐Hydrogenase Mimic in Water

Abstract We report a biomimetic system for light‐driven CO 2 conversion in lipid bilayers using a [FeFe]‐hydrogenase‐inspired molecular dyad ( PS‐CAT ) acting simultaneously as photosensitizer and catalyst. The molecular design of PS‐CAT consists of both light‐harvesting and catalytically active moieties in a single molecule. This structure allows for efficient charge transfer between these two moieties. The PS‐CAT consists of only an organic chromophore and an iron complex. Photocatalytic reduction of CO 2 to CO (CO 2 RR) as well as H 2 production (HER) was traced over 56 h to determine CO 2 RR/HER selectivity. The presence of water in the lipid bilayer system allows for CO 2 RR selectivity >99 % over the competitive HER, outperforming previous molecular, and liposome‐based systems for light‐driven CO 2 to CO conversion. The product selectivity in CO 2 RR (e.g., CO, HCOO − , and CH 4 ) was determined via gas chromatography and NMR spectroscopy with 13 C‐labeled carbon sources. The Stern–Volmer quenching studies on the initial light‐driven electron‐transfer revealed static quenching and indicated a preassembly of the PS‐CAT with the electron donor at the membrane‐water interface.