Selective electrochemical CO2 reduction on Cu-Pd heterostructure

Abstract In this work, a novel Cu-Pd heterostructure, derived from CuCl-PdOx hexagonal microplates, was prepared to tune selective single hydrocarbon production from electrochemical CO2 reduction. The CuCl-PdOx hexagonal microplates were synthesized by a dual-potential electrodeposition technique, followed by electrochemical reduction to form Cu-Pd heterostructure. This Cu-Pd heterostructure exhibited a much higher CO2-to-CH4 selectivity (32 % Faradaic efficiency, FE) compared to pure Cu or Pd. Moreover, Cu-Pd heterostructure showed excellent suppression on C2H4 generation (below 1 % FE). The density functional theory calculations suggested that the hollow site of Pd region in the Cu-Pd heterostructure could stablize CO* intermediate and selectively lowered the energy demand for CH4 formation rather than C2H4. This work provides new opportunities of designing Cu-based electrocatalysts for selective CO2 reduction to single hydrocarbon.