Currently, it is a significant challenge to design and fabricate Cu-based catalysts capable of efficiently catalyzing the electrochemical CO2 reduction reaction (CO2RR) to produce C2+ products. Inspired by the distinct roles of Cu+ and Cu0 sites, a series of catalysts with Cu2O/Cu heterostructures featuring well-defined Cu2O(111)/Cu(111) interfaces were synthesized via a simple chemical reduction method based on octahedral Cu2O catalysts. The optimized catalyst 360-Cu2O/Cu exhibited a C2H4 Faradaic efficiency (FE) of 30.7% and a total C2+ FE of 44.3%, with a partial current density of 12.9 mA cm-2 in an H-cell. In the flow cell, FEC2+ increased to 53.2% at a constant current density of 50 mA cm-2. In situ ATR-FTIR spectroscopy, CO2/CO cofeeding experiments, and DFT calculations collectively revealed that the Cu2O/Cu interface enhanced the activation of CO2 molecules and significantly reduced the energy barriers for both the hydrogenation of the key intermediate *CO and the subsequent asymmetric C-C coupling between *CO and *COH, thereby promoting the formation of the *COCOH intermediate for efficient C2+ production. This work presents a synthesis method for high-performance Cu-based CO2RR catalysts and elucidates the interfacial effect in promoting C2+ selectivity, offering an insightful perspective for the future design of advanced electrocatalysts for CO2RR.
Liu et al. (Wed,) studied this question.