Regulating the interfacial charge transfer and constructing symmetry-breaking sites for the enhanced N₂ electroreduction activity

The Haber–Bosch process for industrial NH₃ production is energy-intensive with heavy CO₂ emissions. Electrochemical N₂ reduction reaction (NRR) is an attractive carbon-neutral alternative for NH₃ synthesis, while the challenge associated with N₂ activation highlights the demand for efficient electrocatalysts. Herein, we demonstrate that PdCu nanoparticles with different Pd/Cu ratios anchored on boron nanosheet (PdCu/B) behave as efficient NRR electrocatalysts toward NH₃ synthesis. Theoretical and experimental results confirm that the highly efficient NH₃ synthesis can be achieved by regulating the charge transfer between interfaces and forming a symmetry-breaking site, which not only alleviates the hydrogen evolution but also changes the adsorption configuration of N₂ and thus optimizes the reaction pathway of NRR over the separated Pd sites. Compared with monometallic Pd/B and Cu/B, the PdCu/B with the optimized Pd/Cu ratio of 1 exhibits superior activity and selectivity for NH₃ synthesis. This study provides new insight into developing efficient catalysts for small energy molecule catalytic conversion via regulating the charge transfer between interfaces and constructing symmetry-breaking sites.