Selective electrochemical CO₂ reduction on Cu-Pd heterostructure

In this work, a novel Cu-Pd heterostructure, derived from CuCl-PdO_x hexagonal microplates, was prepared to tune selective single hydrocarbon production from electrochemical CO₂ reduction. The CuCl-PdO_x 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.