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

The high-grade C2+ products from CO2 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 C2H6 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 C2H6 formation. (3) The synergetic OVs and Au sites allowed efficient e-/H+ to boost *CO hydrogenation toward *CH3 and *CH3*CH3 formation into the C2H6 product.