Nanoporous Intermetallic Pd3Bi for Efficient Electrochemical Nitrogen Reduction

• Published in: Advanced materials (Weinheim) Vol. 33; no. 18
• Main Authors: Wang, Xuejing, Luo, Min, Lan, Jiao, Peng, Ming, Tan, Yongwen
• Format: Journal Article
• Language: English
• Published: Weinheim Wiley Subscription Services, Inc 01.05.2021
• Subjects: Ambient temperature; Ammonia; Chemical reduction; Coupling (molecular); Density functional theory; electrocatalytic nitrogen reduction; Electron transport; intermetallics; nanoporous alloys; Nitrogen; Nitrogenation; Pd 3Bi; Selectivity; Sulfuric acid
• ISSN: 0935-9648; 1521-4095
• DOI: 10.1002/adma.202007733

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 Pd3Bi prepared by converting chemically etched nanoporous PdBi2 exhibits efficient electrocatalytic nitrogen reduction under ambient conditions. The resulting nanoporous intermetallic Pd3Bi 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 H2SO4 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 Pd3Bi, in which the Bi sites can absorb N2 molecules and lower the energy barrier of *N2 for N2 adsorption and activation. Meanwhile, the intermetallic Pd3Bi with bicontinuous nanoporous structure can accelerate the electron transport during the NRR process, thus improving the NRR performance. Nanoporous ordered intermetallic Pd3Bi is prepared through electrochemical etching of PdBi2, and it can achieve extraordinary catalytic performance with high selectivity and excellent stability for electrochemical nitrogen reduction reaction (NRR) at ambient conditions. The intermetallic interaction between the Pd and neighboring Bi sites in nanoporous Pd3Bi can stabilize the transition state and lower the barrier for efficient NRR.