Recent Trends in Bioinspired Photocatalysis and Photoenzymatic Catalysis for CO2 Reduction to Formic Acid

The conversion of CO₂ into fuels and chemical feedstocks represents a sustainable pathway to develop carbon-neutral economy. Typically, among the accessible C1 commodities, formic acid has been a critical liquid product of CO₂ reduction as an essential chemical intermediate or hydrogen storage medium. However, the activity and selectivity regulation of CO₂-to-HCOOH are still far from the scale implementation requirement due to both thermodynamic and kinetic challenges. Billions of years of evolution have allowed natural CO₂ reductases to achieve CO₂ selective utilization by their unique active sites surrounded by elaborate protein scaffolds, confined pockets for reaction intermediates, long-range electron and proton delivery chains, and hydrophobic CO₂ transfer channels. Consequently, learning from formate dehydrogenase (FDH) may inspire novel design in artificial photosynthesis, including the reactive center, multilevel coordination microenvironments, substrate channel, and synergistic effect. Herein, recent works about biomimetic photocatalysis and photoenzymatic catalysis of CO₂ valorization to HCOOH are summarized, which is hoped to lift the application of bioinspiration in highly selective CO₂ reduction systems.