Wang Xuejing, Luo Min, Lan Jiao, Peng Ming, Tan Yongwen
College of Materials Science and Engineering, Hunan University, Changsha, Hunan, 410082, China.
Department of Physics, Shanghai Polytechnic University, Shanghai, 201209, China.
Adv Mater. 2021 May;33(18):e2007733. doi: 10.1002/adma.202007733. Epub 2021 Apr 1.
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 Pd Bi prepared by converting chemically etched nanoporous PdBi exhibits efficient electrocatalytic nitrogen reduction under ambient conditions. The resulting nanoporous intermetallic Pd Bi can achieve high activity and selectivity with an NH yield rate of 59.05 ± 2.27 µg h mg and a Faradaic efficiency of 21.52 ± 0.71% at -0.2 V versus the reversible hydrogen electrode in 0.05 m H SO 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 Pd Bi, in which the Bi sites can absorb N molecules and lower the energy barrier of *N for N adsorption and activation. Meanwhile, the intermetallic Pd Bi with bicontinuous nanoporous structure can accelerate the electron transport during the NRR process, thus improving the NRR performance.
常温下的电催化氮还原是一种用于人工固氮的绿色技术，但面临着产率低和选择性差的巨大挑战。在此，通过对化学蚀刻的纳米多孔PdBi进行转化制备的纳米多孔有序金属间化合物PdBi在环境条件下表现出高效的电催化氮还原性能。在0.05 m H₂SO₄电解液中，相对于可逆氢电极，所得的纳米多孔金属间化合物PdBi在-0.2 V时可实现高活性和选择性，NH₃产率为59.05 ± 2.27 μg h mg⁻¹，法拉第效率为21.52 ± 0.71%，在电化学氮还原反应（NRR）中优于大多数已报道的催化剂。原位X射线吸收光谱研究结合密度泛函理论计算表明，Pd-Bi位点之间的强耦合连接了金属间化合物PdBi的电子转移通道，其中Bi位点可以吸附N₂分子并降低*N的能垒以促进N的吸附和活化。同时，具有双连续纳米多孔结构的金属间化合物PdBi可以加速NRR过程中的电子传输，从而提高NRR性能。
