Cooperative dual single atom Ni/Cu catalyst for highly selective CO2-to-ethanol reduction

Abstract

The electrochemical CO2-to-ethanol conversion bargains a promising approach to lowering CO2 emission while yielding valuable chemical products. Here, we report the NiCu-SACs/N-C catalysts with cooperative dual heteroactive sites that achieve by far the highest catalytic activity for yielding ethanol with the unprecedented Faradaic efficiency of 92.2 % at the potential of −0.6 V versus RHE. The catalyst exhibits the lowest onset potential of −0.4 V versus RHE to catalyze CO2-to-ethanol conversion. In-operando X-ray absorption spectroscopy provides an interesting observation of restructuring behavior of dynamically generated Cu clusters from atomically distributed Cu single-atoms and reversible structural changes or oxidation states of Cu sites while Ni sites remain unchanged during the catalytic reactions. Our experimental analysis and DFT computation suggest that CO produced on Cu-N4/Ni-N3 cooperative single atom sites undergoes C-C coupling, which is further reduced into ethanol. This strategy provides a new route to design selective and efficient catalysts for CO2-to-ethanol conversion.