Pt<sub>1</sub>Bi\nSingle-Atom Alloy for a Coupled Photocatalytic\nCO<sub>2</sub> Reduction and Aryl Olefin Oxidation System

Solar-driven CO<sub>2</sub> reduction\nprovides a promising\nstrategy\nto produce fuels and value-added chemicals, while the efficiency and\neconomy of the system are often limited by the coupled oxidation half-reaction.\nHere, we develop a synergistic system coupling photocatalytic CO<sub>2</sub> reduction to CO and aryl olefin oxidation to aryl ketone\nwith a high-efficiency and improved atom economy over a TiO<sub><i>x</i></sub>-supported Pt<sub>1</sub>Bi single-atom alloy photocatalyst.\nCombined experimental and computational studies elucidate the spontaneous\nelectron transfer from Bi to Pt in the dark, which is enhanced under\nlight radiation. Density functional theory calculations reveal that\nthe oxidation process of aryl olefin favors the protonation of CO<sub>2</sub> and the dissociation of COOH* to CO*, and Bi facilitates\nCO<sub>2</sub> protonation and CO desorption on the Pt site. The generation\nrate of CO reaches 391 μmol g<sup>–1</sup> h<sup>–1</sup> with an electron selectivity of 91.4% using alpha-methylstyrene\nas the substrate, and the yield of the acetophenone product is 449\nμmol g<sup>–1</sup> h<sup>–1</sup> with a 95.5%\nselectivity.