Development of an Integrated System for Highly Selective Photoenzymatic Synthesis of Formic Acid from CO2

Abstract Herein, a Zr‐based dual‐ligand MOFs with pre‐installed Rh complex was employed for NADH regeneration in situ and also used for immobilization of formic acid dehydrogenase (FDH) in order to realize a highly efficient CO 2 fixation system. Then, based on the detailed investigations into the photochemical and electrochemical properties, it is demonstrated that the introduction of the photosensitive meso‐tetra(4‐carboxyphenyl) porphin (TCPP) ligands increased the catalytic active sites and improved photoelectric properties. Furthermore, the electron mediator Rh complex, anchored on the zirconium‐based dual‐ligand MOFs, enhanced the efficiency of electron transfer efficiency and facilitated the separation of photogenerated electrons and holes. Compared with UiO‐66‐NH 2 , Rh‐H 2 TCPP‐UiO‐66‐NH 2 exhibits an optimized valence band structure and significantly improved photocatalytic activity for NAD + reduction, resulting the synthesis of formic acid from CO 2 increased from 150 μg mL −1 (UiO‐66‐NH 2 ) to 254 μg mL −1 (Rh‐H 2 TCPP‐UiO‐66‐NH 2 ). Moreover, the assembled photocatalyst‐enzyme coupled system also allows facile recycling of expensive electron mediator, enzyme, and photocatalyst.