Highly Selective Production of C2+ Oxygenates from CO2 in Strongly Acidic Condition by Rough Ag‐Cu Electrocatalyst

The acidic electrocatalytic conversion of CO2 to multi‐carbon (C2+) oxygenates is of great importance in view of enhancing carbon utilization efficiency and generating products with high energy densities, but suffering from low selectivity and activity. Herein, we synthesized Ag‐Cu alloy catalyst with highly rough surface, by which the selectivity to C2+ oxygenates can be greatly improved. In a strongly acidic condition (pH=0.75), the maximum C2+ products Faradaic efficiency (FE) and C2+ oxygenates FE reach 80.4% and 56.5% at ‐1.9 V versus reversible hydrogen electrode, respectively, with a ratio of FEC2+ oxygenates to FEethylene up to 2.36. At this condition, the C2+ oxygenates partial current density is as high as 480 mA cm‐2. The in situ Raman measurements and control experiments indicate that the high generation of C2+ oxygenates over the catalyst originates from its large surface roughness and Ag alloying.