Regulating reconstruction of oxide-derived Cu for electrochemical CO₂ reduction toward n-propanol.

Abstract

Oxide-derived copper (OD-Cu) is the most efficient and likely practical electrocatalyst for CO₂ reduction toward multicarbon products. However, the inevitable but poorly understood reconstruction from the pristine state to the working state of OD-Cu under strong reduction conditions largely hinders the rational construction of catalysts toward multicarbon products, especially C₃ products like n-propanol. Here, we simulate the reconstruction of CuO and Cu₂O into their derived Cu by molecular dynamics, revealing that CuO-derived Cu (CuOD-Cu) intrinsically has a richer population of undercoordinated Cu sites and higher surficial Cu atom density than the counterpart Cu₂O-derived Cu (Cu₂OD-Cu) because of the vigorous oxygen removal. In situ spectroscopes disclose that the coordination number of CuOD-Cu is considerably lower than that of Cu₂OD-Cu, enabling the fast kinetics of CO₂ reaction and strengthened binding of *C₂ intermediate(s). Benefiting from the rich undercoordinated Cu sites, CuOD-Cu achieves remarkable n-propanol faradaic efficiency up to ~17.9%, whereas the Cu₂OD-Cu dominantly generates formate.