Abstract:Under the global carbon neutrality initiative, the advancement of efficient and low-energy urea synthesis technologies holds crucial importance for sustainable development in agriculture and industry. Electrocatalytic technology enables direct co-reduction of CO2 and NO3– for urea synthesis under ambient conditions, emerging as a highly promising strategy that has garnered significant research interest. Nevertheless, current electrocatalytic systems are constrained by low mass transfer efficiency, insufficient catalytic activity, and poor stability, posing substantial challenges for developing high-performance electrocatalysts. In this study, a honeycomb-like porous AlCuZn alloy catalyst was successfully fabricated through a facile alkali etching approach. At ambient conditions, the optimized AlCuZn-0.5 catalyst demonstrated a remarkable urea Faradaic efficiency of 65.7% at –0.3 V (vs. RHE), representing 1.4-fold enhancement over pristine AlCuZn, with a corresponding yield of 152.4 μg/(h·mgcat) achieving 1.8-fold improvement. Electrochemical cycling tests and pre-/post-reaction X-ray diffraction (XRD) analyses confirmed catalyst's superior operational stability and structural integrity. The etched AlCuZn-0.5 manifests enhanced synergistic effects among Al-Cu-Zn components, which facilitated C-N coupling reactions and improved urea selectivity. Porous architecture of the material not only enhanced reactant mass transfer but also reduced charge transfer resistance while exposing abundant active sites, collectively boosting urea production rate. This work established a novel design paradigm of C-N coupling for efficient electrocatalysis of NO₃^- and CO₂, positioning AlCuZn-0.5 as a prospective catalyst for sustainable urea synthesis.