Dual-Anion-Stabilized Cuδ+ Sites in Cu2(OH)2CO3 for High C2+ Selectivity in the CO2 Electroreduction Reaction

The excessive emission of CO2 has aroused increasingly serious environmental problems. Electrochemical CO2 reduction reaction (CO2RR) is an effective way to reduce CO2 concentration and simultaneously produce highly valued chemicals and fuels. Cu delta+ species are regarded as promising active sites to obtain multi-carbon compounds in CO2RR, however, they are easily reduced to Cu-0 during the reaction and fail to retain the satisfying selectivity for C2+ products. Herein, via a one-step method, we synthesize Cu-2(OH)(2)CO3 microspheres composed of nanosheets, which has achieved a superior Faraday efficiency for C2+ products as high as 76.29 % at -1.55 V vs. RHE in an H cell and 78.07 % at -100 mA cm(-2) in a flow cell. Electrochemical measurements, in situ Raman spectra and attenuated total reflectance infrared spectra (ATR-IR) as well as the theoretic calculation unveil that, compared with Cu(OH)(2) and CuO, the dual O-containing anionic groups (OH- and CO32-) in Cu-2(OH)(2)CO3 can effectively stabilize the Cu delta+ species, promote the adsorption and activation of CO2, boost the coverage of *CO and the coupling of *CO-*COH, thus sustain the flourishment of C2+ products.