Hu Hongyan, Liu Shilong, Sun Hongfei, Sun Wenli, Tang Jike, Wei Lingzhi, Chen Xiaowei, Chen Qianwang, Lin Yichao, Tian Ziqi, Su Jianwei
Institutes of Physical Science and Information Technology, Key Laboratory of Structure and Functional Regulation of Hybrid Materials (Ministry of Education), Anhui University, Hefei, 230601, P. R. China.
School of Material Science and Engineering, Key Laboratory for Ecological-Environment Materials of Jiangsu Province, Yancheng Institute of Technology, Yancheng, 224051, P. R. China.
Small. 2025 May;21(21):e2412096. doi: 10.1002/smll.202412096. Epub 2025 Apr 3.
Iridium (Ir)-based materials are the most widely used oxygen evolution reaction (OER) electrocatalysts in proton exchange membrane water electrolysis (PEMWE). However, their commercial application suffers from high cost and insufficient activity. To optimize the atom utilization efficiency of Ir, the aim is to engineer and develop a rutile-structured solid solution catalyst with minimal Ir content, which is identified through a phase boundary. Here, IrMnO represents the lowest Ir content in the desired IrO-MnO solid solution. The IrMnO catalyst exhibits outstanding OER performance in acidic electrolytes, reaching a remarkable mass activity of 1135 A g at an overpotential of 300 mV, which is ≈50 times higher than that of a commercial IrO catalyst. Additionally, it demonstrates excellent stability at a current density of 200 mA cm over 120 h during PEMWE operations. Density functional theory (DFT) calculations indicate that the hydroxylation process can be efficiently promoted by the electron-withdrawing on Ir sites in IrMnO, contributing to the enhancement of OER activity.
铱（Ir）基材料是质子交换膜水电解（PEMWE）中应用最广泛的析氧反应（OER）电催化剂。然而，它们的商业应用面临成本高和活性不足的问题。为了优化Ir的原子利用效率，目标是设计并开发一种Ir含量最低的金红石结构固溶体催化剂，该催化剂通过相界确定。在此，IrMnO代表所需的IrO-MnO固溶体中的最低Ir含量。IrMnO催化剂在酸性电解质中表现出出色的OER性能，在300 mV过电位下达到了1135 A g的显著质量活性，约为商业IrO催化剂的50倍。此外，在PEMWE运行期间，它在200 mA cm的电流密度下保持120小时以上的优异稳定性。密度泛函理论（DFT）计算表明，IrMnO中Ir位点上的吸电子作用可以有效地促进羟基化过程，有助于提高OER活性。
