Dual Locking of Cu + /Cu 0 Interface and Vacancy Defects via Al‐Doping for Efficient Electroreduction of CO 2 to C 2+ Products

Abstract Multi‐carbon (C 2+ ) products from the electrochemical CO 2 reduction reaction (CO 2 RR) are highly desirable due to their energy density and commercial value. Cu‐based catalysts are the only known materials capable of producing C 2+ products with appreciable efficiency. However, the low *CO intermediate coverage and sluggish C‐C coupling kinetics hinder their selectivity. Herein, an Al‐doped copper hydroxyfluoride (Al‐CuOHF) catalyst that combines dynamic reconstruction with electronic modulation is reported. In/ex situ CO 2 RR characterization confirm that partial Al dissolution drives in situ reconstruction of porous Cu 2 O/Cu heterostructures with abundant oxygen vacancies (O v ), while residual Al stabilizes Cu + species and F‐O v Lewis acid‐base pairs. In situ Raman spectroscopy directly evidences enhanced *CO adsorption on restructured surfaces. These synergistic effects facilitate CO 2 activation, elevate *CO coverage, and reduce the energy barrier for C‐C coupling. Consequently, Al‐CuOHF delivers a remarkable C 2+ Faradaic efficiency of 83.3% and a partial current density of −93.03 mA cm −2 at −1.0 V (vs. RHE). This work provides a strategy for constructing multifunctional interfaces via dopant‐guided structural evolution and electronic field engineering, offering new insights into high‐efficiency CO 2 electroreduction.