Photocatalytic asymmetric C-C coupling for CO₂ reduction on dynamically reconstructed Ru^δ+-O/Ru⁰-O sites.

Abstract

Solar-driven CO₂ reduction to value-added C₂ chemicals is thermodynamically challenging due to multiple complicated steps. The design of active sites and structures for photocatalysts is necessary to improve solar energy efficiency. In this work, atomically dispersed Ru-O sites in Ru_xIn_2-xO₃ are constructed by interior lattice anchoring of Ru. This results in the dynamic reconstruction of Ru^δ+-O/Ru⁰-O sites upon photoexcitation, which facilitates the CO₂ activation, *CO intermediates adsorption, and C-C coupling as demonstrated by varied in situ techniques. A SiO₂ core in Ru_xIn_2-xO₃/SiO₂ construction further enhances the solar energy utilization and individual Ru_xIn_2-xO₃ nanocrystals dispersion for photocatalytic CO₂ reduction reaction. It results in the maximum ethanol production rate up to 31.6 μmol/g/h with over 90% selectivity. DFT simulation reveals that the C₂ dimer formation primarily underwent an asymmetric *CO-*CHO coupling route via a low-energy precedence ladder of *CHO. This work provides an insightful understanding of active sites with dynamic reconstruction towards asymmetric C-C coupling for CO₂RR at the atomic scale.