Modulating Single‐Atom Palladium Sites with Copper for Enhanced Ambient Ammonia Electrosynthesis

Abstract

The electrochemical reduction of N₂ to NH₃ is emerging as a promising alternative for sustainable and distributed production of NH₃ . However, the development has been impeded by difficulties in N₂ adsorption, protonation of *NN, and inhibition of competing hydrogen evolution. To address the issues, we design a catalyst with diatomic Pd-Cu sites on N-doped carbon by modulation of single-atom Pd sites with Cu. The introduction of Cu not only shifts the partial density of states of Pd toward the Fermi level but also promotes the d-2π* coupling between Pd and adsorbed N₂ , leading to enhanced chemisorption and activated protonation of N₂ , and suppressed hydrogen evolution. As a result, the catalyst achieves a high Faradaic efficiency of 24.8±0.8 % and a desirable NH₃ yield rate of 69.2±2.5 μg h^-1 mg_cat. ^-1 , far outperforming the individual single-atom Pd catalyst. This work paves a pathway of engineering single-atom-based electrocatalysts for enhanced ammonia electrosynthesis.