Abstract: Zn-doped CuSe nanosheets were electrochemically reconstructed into ZnCu alloy catalysts for the co-electroreduction of CO₂ and nitrate to urea. The influence of varying Zn doping concentrations on the electrocatalytic performance was systematically investigated. The findings revealed that the CuSe nanosheets were reduced in situ to porous Cu nanosheets, generating a significant number of grain-boundary active sites. The incorporation of Zn atoms modulated the electronic structure of the ZnCu alloy. The synergistic interaction between Cu and Zn sites enhanced the adsorption of reactants and facilitated the C-N coupling reaction for urea formation. Upon optimization of Zn content, the Zn_2.8Cu_97.2 alloy delivered the best performance, achieving a urea yield of 2.18 µmol·h⁻¹·cm⁻² with a Faradaic efficiency of 34.7% at a low potential of −0.2 V vs. RHE. The proposed electrochemical reconstruction strategy provides a robust approach for the rational design of bimetallic-site catalysts and demonstrates significant potential for future applications in electrochemical synthesis.