Qian Zheng-Xin, Liang Ge-Hao, Shen Liang-Fei, Zhang Ge, Zheng Shisheng, Tian Jing-Hua, Li Jian-Feng, Zhang Hua
College of Materials, Institute of Artificial Intelligence, State Key Laboratory of Physical Chemistry of Solid Surfaces, College of Chemistry and Chemical Engineering, iChEM, Fujian Key Laboratory of Advanced Materials, College of Energy, Xiamen University, Xiamen 361005, China.
Innovation Laboratory for Sciences and Technologies of Energy Materials of Fujian Province (IKKEM), Xiamen 361102, China.
J Am Chem Soc. 2025 Jan 8;147(1):1334-1343. doi: 10.1021/jacs.4c15847. Epub 2024 Dec 25.
Nickel-iron-based catalysts are recognized for their high efficiency in the oxygen evolution reaction (OER) under alkaline conditions, yet the underlying mechanisms that drive their superior performance remain unclear. Herein, we revealed the molecular OER mechanism and the structure-intermediate-performance relationship of OER on a phosphorus-doped nickel-iron nanocatalyst (NiFeP). NiFeP exhibited exceptional activity and stability with an overpotential of only 210 mV at 10 mA cm in 1 M KOH and a cell voltage of 1.68 V at 1 A cm in anion exchange membrane water electrolyzers. The evolution of active sites and intermediates during OER on NiFeP was in situ probed and correlated using shell-isolated nanoparticle-enhanced Raman spectroscopy, complemented by differential electrochemical mass spectrometry and density functional theory. These results provide direct evidence that OER proceeds via the lattice oxygen-mediated mechanism. Remarkably, phosphorus doping plays a critical role in stabilizing the active β-Ni(Fe)OOH phase, which facilitates the *OH deprotonation and the subsequent O-O coupling to form *OO intermediates. Our findings offer a deeper understanding of the OER mechanism, providing a clear pathway for designing next-generation OER catalysts with improved efficiency and durability.
镍铁基催化剂因其在碱性条件下析氧反应（OER）中的高效率而受到认可，但其优异性能背后的驱动机制仍不清楚。在此，我们揭示了磷掺杂镍铁纳米催化剂（NiFeP）上的分子OER机制以及OER的结构-中间体-性能关系。在1 M KOH中，NiFeP在10 mA cm时过电位仅为210 mV，在阴离子交换膜水电解槽中1 A cm时电池电压为1.68 V，表现出优异的活性和稳定性。利用壳层隔离纳米粒子增强拉曼光谱原位探测并关联了NiFeP上OER过程中活性位点和中间体的演变，并辅以差分电化学质谱和密度泛函理论。这些结果提供了直接证据，表明OER通过晶格氧介导机制进行。值得注意的是，磷掺杂在稳定活性β-Ni(Fe)OOH相方面起着关键作用，这有利于OH去质子化以及随后的O-O偶联形成OO中间体。我们的发现为OER机制提供了更深入的理解，为设计具有更高效率和耐久性的下一代OER催化剂提供了清晰的途径。
