Multifunctional Au/Hydroxide Interface toward Enhanced C–C Coupling for Solar-Driven CO₂ Reduction into C₂H₆

Abstract

The high-grade C 2+ products from CO 2 photoreduction are limited by the kinetic bottleneck. Herein, a multifunctional Au/hydroxide interface was put forward to improve the C–C coupling. As a prototype, the synthesized Au/ZnSn(OH) 6 tuned the CO generation and afforded about 50% electrons toward C 2 H 6 selectivity. The prominent enhancement resulted from the following effects: (1) strong metal–support electronic interactions built an electric field at the interface of ZnSn(OH) 6 nearby the Au nanoparticles, leading to fast transfer of electrons for the C–H and C–C bonding reactions. (2) The surface solid-state Sn–OH and Zn–OH lattice hydroxyls served as donors to feed rich H + and oxygen vacancies (OVs) via hole-induced oxidation for the boosted C 2 H 6 formation. (3) The synergetic OVs and Au sites allowed efficient e – /H + to boost *CO hydrogenation toward *CH 3 and *CH 3 *CH 3 formation into the C 2 H 6 product.