Highly dispersed nickel site catalysts for diluted CO2 photoreduction to CO with nearly 100% selectivity

Photoconversion of CO 2 into value-added fuels has aroused widespread interest; however, this process is significantly limited by the inefficient thermodynamics and sluggish reaction dynamics in the diluted CO 2 . To circumvent these obstacles, we design a bipyridine-based polyimide polymer for anchoring single Ni site for diluted CO 2 photoreduction. The desired Ni single atomic catalysts achieve high generation activity of ∼ 2262 μmol/h with apparent quantum efficiency (A.Q.E.) of 0.20% for CO 2 -to-CO in 0.1 atm CO 2 pressure. No measurable H 2 is produced in the catalytic process, affording nearly 100% CO selectivity over water splitting. This superior activity and selectivity outperform most previous atomical catalysts. Mechanistic analyses elucidate that the highly dispersed Ni atoms act as active sites for effective CO 2 binding and activation, and stabilize the rate-determining step of intermediates for CO generation. This work discloses the relationship between catalytic properties and single atoms for efficient solar-driven diluted CO 2 reduction.