Nanoporous Intermetallic Pd₃Bi for Efficient Electrochemical Nitrogen Reduction

Electrocatalytic nitrogen reduction at ambient temperature is a green technology for artificial nitrogen fixation but greatly challenging with low yield and poor selectivity. Here, a nanoporous ordered intermetallic Pd₃ Bi prepared by converting chemically etched nanoporous PdBi₂ exhibits efficient electrocatalytic nitrogen reduction under ambient conditions. The resulting nanoporous intermetallic Pd₃ Bi can achieve high activity and selectivity with an NH₃ yield rate of 59.05 ± 2.27 µg h⁻¹ mgcat ⁻¹ and a Faradaic efficiency of 21.52 ± 0.71% at -0.2 V versus the reversible hydrogen electrode in 0.05 m H₂ SO₄ electrolyte, outperforming most of the reported catalysts in electrochemical nitrogen reduction reaction (NRR). Operando X-ray absorption spectroscopy studies combined with density functional theory calculations reveal that strong coupling between the Pd-Bi sites bridges the electron-transfer channel of intermetallic Pd₃ Bi, in which the Bi sites can absorb N₂ molecules and lower the energy barrier of *N₂ for N₂ adsorption and activation. Meanwhile, the intermetallic Pd₃ Bi with bicontinuous nanoporous structure can accelerate the electron transport during the NRR process, thus improving the NRR performance.