This work presents the relationship

This work presents the relationship between intermediate adsorption energies and NO3-RR activity on CuNi catalysts. By replacing 50% Cu with Ni, we achieved significantly improved NO3-RR-to-NH3 performance. This includes a 0.12 V upshift in the half-wave potential, a 0.2 V lower overpotential required to achieve the optimal NH3 FE, and a 6-fold increase in NO3-RR activity on Cu50Ni50 alloy catalysts compared to pure Cu at 0 V vs. RHE in alkaline conditions (pH = 14). The electronic structure studies revealed an upshifting of the d-band center toward the Fermi level, a feature that enhances intermediate adsorption energies. This relationship was then validated by our DFT calculations, wherein we found that introducing Ni atoms moves the PDS from NO3- adsorption to *NH2 hydrogenation due to the enhanced adsorption energy of NO3- on the CuNi surface, and as a result, lowers the overpotential. Our work demonstrates the effect of the d-band center positions and the induced adsorption properties on the NO3-RR activity and selectivity. This work highlights a promising route to design catalysts for selective NO3-RR to NH3.