Multiple Tuning of the Local Environment Enables Selective CO₂ Electroreduction to Ethylene in Neutral Electrolytes

Abstract Recently, vigorous progress is made in the selective and high‐current reduction of carbon dioxide (CO₂) to ethylene (C₂H₄) by using a flow cell. In most cases, however, the reduction is only achieved in strong alkaline electrolytes, which results in substantial deactivation of electrocatalysts due to the accumulation of precipitates. Here, porous Cu nanowires (NWs) is prepared with abundant atomic defects, which create a synergy with the pore‐induced electric field to comprehensively tune the local microenvironment of the electrode surface, thus enabling efficient and stable C₂H₄ production from the CO₂ reduction reaction (CO₂RR) in neutral media. In particular, the enhanced electric field effect increases the local K⁺ concentration for the generation of *CO intermediates; while the atomic defects stabilize OH⁻ and *CO, leading to high local pH and *CO coverage. Such synergy can provide a favorable local environment and high *CO coverage for significantly decreasing the energy barrier of the C─C coupling step. Consequently, a large partial C₂H₄ current density of 222.3 mA cm⁻² with excellent stability is achieved in a neutral electrolyte. Altogether, this work paves new pathways to promote C₂H₄ production in the neutral CO₂RR through multiple tuning of the local environment.