Nanoporous Intermetallic Pd3 Bi 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.