中国科学院宁波材料技术与工程研究所陆之毅团队报道了锶掺杂IrOx触发直接O-O偶联促进酸性水氧化电催化。相关研究成果于2024年10月10日发表于国际一流学术期刊《德国应用化学》。

在酸性条件下开发高效稳定的析氧反应（OER）电催化剂对于质子交换膜水电解槽的商业化至关重要。

该文中，研究人员提出了一种Sr(OH)₂辅助方法来制备（200）面高度暴露的掺锶IrOx催化剂，以提供具有较低Ir-O共价性的可用相邻铱位点。这种设计促进了酸性水氧化过程中的直接O-O偶联，从而绕过了与*OOH中间体产生相关的高能屏障。

受益于这一优势，在0.5 M H₂SO₄中，在10 mA cm^-2的电流密度下，所得Sr-IrOx催化剂表现出令人印象深刻的207 mV过电位。此外，使用Sr-IrOx作为阳极催化剂的PEMWE装置在1 A cm^-2下显示出1.72 V的电池电压，并在500多小时内保持优异的稳定性。

该工作不仅为改进的酸性OER催化剂的设计提供了指导，还鼓励开发具有其他电催化反应新机制的铱基电催化剂。

附：英文原文

Title: Strontium Doped IrOx Triggers Direct O-O Coupling to Boost Acid Water Oxidation Electrocatalysis

Author: Zhiyi Lu, Wuyong Zhang, Caihan Zhu, Yingjie Wen, Minli Wang, Yunan Wang

Issue&Volume: 2024-10-10

Abstract: The discovery of efficient and stable electrocatalysts for the oxygen evolution reaction (OER) in acidic conditions is crucial for the commercialization of proton-exchange membrane water electrolyzers. In this work, we propose a Sr(OH)2-assisted method to fabricate a (200) facet highly exposed strontium-doped IrOx catalyst to provide available adjacent iridium sites with lower Ir-O covalency. This design facilitates direct O-O coupling during the acidic water oxidation process, thereby circumventing the high energy barrier associated with the generation of *OOH intermediates. Benefiting from this advantage, the resulting Sr-IrOx catalyst exhibits an impressive overpotential of 207 mV at a current density of 10 mA cm-2 in 0.5 M H2SO4. Furthermore, a PEMWE device utilizing Sr-IrOx as the anodic catalyst demonstrates a cell voltage of 1.72 V at 1 A cm-2 and maintains excellent stability for over 500 hours. Our work not only provides guidance for the design of improved acidic OER catalysts but also encourages the development of iridium-based electrocatalysts with novel mechanisms for other electrocatalytic reactions.

DOI: 10.1002/anie.202418456

Source: https://onlinelibrary.wiley.com/doi/10.1002/anie.202418456