Atomically Dispersed Ni-Cu Catalysts for pH-Universal CO 2 Electroreduction.

CO 2 electroreduction is of great significance to reduce CO 2 emissions and complete the carbon cycle. However, the unavoidable carbonate formation and low CO 2 utilization efficiency in neutral or alkaline electrolytes hinder its application at commercial scale. The development of CO 2 reduction under acidic conditions provides a promising strategy, but the inhibition of hydrogen evolution reaction is difficult. Herein, we report the first work to design in a Ni-Cu dual-atom catalyst supported on the hollow nitrogen-doped carbon for pH-universal CO 2 electroreduction to CO. The catalyst showed high CO Faradaic efficiency of ∼99% in acidic, neutral and alkaline electrolytes, and the partial current densities of CO reach 190 ± 11 mAcm -2 , 225 ± 10 mA cm -2 and 489 ± 14 mA cm -2 , respectively. In particular, the CO 2 utilization efficiency under acidic conditions reaches 64.3%, which is twice higher than that of alkaline conditions. Detailed study indicates the existence of electronic interaction between Ni and Cu atoms. The Cu atoms pushes the Ni d band center further towards the Fermi level, and thereby accelerating the formation of *COOH. In addition, operando characterizations and density functional theory calculation were used to elucidate the possible reaction mechanism of CO 2 -to-CO under acidic and alkaline electrolytes. This article is protected by copyright. All rights reserved.