Engineering NH-Cu-NH Triple-atom Sites in Defective MOFs for Selective Overall Photoreduction of CO into CHCOCH.

Selective photoreduction of CO to multicarbon products, is an important but challenging task, due to high CO activation barriers and insufficient catalytic sites for C-C coupling. Herein, a defect engineering strategy for incorporating copper sites into the connected nodes of defective metal-organic framework UiO-66-NH for selective overall photo-reduction of CO into acetone. The Cu site in well-modified CuNO units served as a trapping site to capture electrons via efficient electron-hole separation, forming the active Cu site for CO reduction. Two NH groups in CuNO unit adsorb CO and cooperated with copper ion to functionalize as a triple atom catalytic site, each interacting with one CO molecule to strengthen the binding of *CO intermediate to the catalytic site. The deoxygenated *CO attached to the Cu site interacted with CH fixed at one amino group to form the key intermediate CO-CH, which interacted with the third reduction intermediate on another amino group to produce acetone. Our photocatalyst realizes efficient overall CO reduction to C product acetone CHCOCH with an evolution rate of 70.9 μmol g  h and a selectivity up to 97 % without any adducts, offering a promising avenue for designing triple-atomic sites to producing C product from photosynthesis with water.