Selective\nPhotocatalytic Conversion of CO<sub>2</sub> to Ethanol via Unsaturated\nCu–O Domains

Enhancing\nthe selectivity of photocatalytic CO<sub>2</sub> reduction\nto valuable multicarbon (C<sub>2+</sub>) products remains a significant\nchallenge in green synthetic chemistry. Here, we present a dual-center\nstrategy for metal oxides that boosts the photochemical conversion\nof CO<sub>2</sub> to ethanol by regulating the coordination number\nof metal and oxygen sites. Notably, CuO catalysts rich in low-coordinated\nCu–O domains have achieved nearly perfect ethanol selectivity\n(96.9%), extraordinary durability (60 h), and a superior yield rate\nof 30.5 μmol·g<sup>–1</sup>·h<sup>–1</sup>, surpassing the performance of many existing photocatalysts in water\nvapor and CO<sub>2</sub>. Density functional theory calculations and\noperando spectroscopic results provide conclusive evidence that tricoordinated\ncopper (Cu<sub>3c</sub>) increases the coverage of key *CO species,\nwhile bicoordinated oxygen (O<sub>2c</sub>) controls the migration\nof *CO species, thereby effectively reducing the energy requirement\nfor *CO dimerization into *OC–CO intermediates (Δ<i>G</i><sub><i>*</i>OC–CO</sub> = −0.56\neV) in the ethanol pathway. This work offers valuable insights for\ndesigning photocatalysts that exhibit improved selectivity for C<sub>2+</sub> fuels.