Selective CO2 Photoreduction to Acetate at Asymmetric Ternary Bridging Sites.

Photoreduction of CO2 is a promising strategy to synthesize value-added fuels or chemicals and realize carbon neutralization. Noncopper catalysts are seldom reported to generate C2 products, and the selectivity over these catalysts is low. Here, we design rich-interface, heterostructured In2O3/InP (r-In2O3/InP) for highly competitive photocatalytic CO2-to-CH3COOH conversion with a productivity of 96.7 µmol g-1 and selectivity > 96% along with water oxidation to O2 in pure water (no sacrificial agent) under visible light irradiation. The hard X-ray absorption near-edge structure (XANES) shows that the formation of r-In2O3/InP with the isogenesis cation adjusts the coordination environment via interface engineering and forms O-In-P polarized sites at the interface. In situ FT-IR and Raman spectra identify the key intermediates of OCCO* for acetate production with high selectivity. Density functional theory (DFT) calculations reveal that r-In2O3/InP with rich O-In-P polarized sites promotes C-C coupling to form C2 products because of the imbalanced adsorption energies of two carbon atoms. This work reports an interesting indium-based photocatalyst for selective CO2 photoreduction to acetate under strict solution and irradiation conditions and provides significant insights into fabricating interfacial polarization sites to promote the process.