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

Abstract

Photoconversion of CO2 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 CO2. To circumvent these obstacles, we design a bipyridine-based polyimide polymer for anchoring single Ni site for diluted CO2 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 CO2-to-CO in 0.1 atm CO2 pressure. No measurable H2 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 CO2 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 CO2 reduction.