近日，青岛科技大学秦清团队发现低几何铱密度掺钕空心Ir/IrO₂纳米球具有优异的酸性水氧化性能。相关论文于2025年4月18日发表在《结构化学》杂志上。

在保持阳极催化剂层的催化性能和机械鲁棒性的同时减少Ir负载仍然是大规模实施质子交换膜水电解（PEMWE）的关键挑战。在此，研究组提出了一种结构工程策略，涉及掺钕Ir/IrO₂（Nd-Ir/IrO₂）中空纳米球，其壳厚和腔尺寸可精确调节。优化的催化剂在酸性介质中表现出优异的析氧反应（OER）性能，在10mA cm^-2的基准电流密度下实现了259mV的极低过电位，同时与商业IrO₂和Ir/IrO₂对应物相比，表现出显著增强的耐久性。

值得注意的是，Nd-Ir/IrO₂催化剂在1.50 V比RHE下的质量活性为541.6 a g_Ir^-1，比传统IrO₂提高了74.5倍。通过全面的电化学分析和先进的表征技术表明，分层中空结构同时满足了多个关键要求：（i）通过增强的电化学表面积实现了丰富的暴露活性位点，（ii）通过工程孔隙优化了传质途径，以及（iii）通过连续的导电框架保持了结构完整性，共同实现了在不损害催化层性能的情况下显著减少铱负载。

基础机理研究进一步揭示，Nd掺杂诱导了稳定晶格氧的临界界面Nd-O-Ir构型，以及混合价Ir之间增强的电子效应，抑制了OER过程中Ir活性位点的过度氧化，协同确保了增强的催化耐久性。该工作建立了一种将纳米级建筑工程与原子级杂原子掺杂相结合的双调制范式，为高性能PEMWE系统提供了一条可行的途径，大大降低了贵金属的要求。

附：英文原文

Title: Neodymium-doped hollow Ir/IrO2 nanospheres with low geometric iridium density enable excellent acidic water oxidation performance

Author: anonymous

Issue&Volume: 2025-04-18

Abstract: Reducing the Ir loading while preserving catalytic performance and mechanical robustness in anodic catalyst layers remains a critical challenge for the large-scale implementation of proton exchange membrane water electrolysis (PEMWE). Herein, we present a structural engineering strategy involving neodymium-doped Ir/IrO2 (Nd-Ir/IrO2) hollow nanospheres with precisely adjustable shell thickness and cavity dimensions. The optimized catalyst demonstrates excellent oxygen evolution reaction (OER) performance in acidic media, achieving a remarkably low overpotential of 259 mV at a benchmark current density of 10 mA cm-2 while exhibiting substantially enhanced durability compared to commercial IrO2 and Ir/IrO2 counterparts. Notably, the Nd-Ir/IrO2 catalyst delivers a mass activity of 541.6 A gIr-1 at 1.50 V vs RHE, representing a 74.5-fold enhancement over conventional IrO2. Through comprehensive electrochemical analysis and advanced characterization techniques reveal that, the hierarchical hollow architecture simultaneously addresses multiple critical requirements: (i) abundant exposed active sites enabled by an enhanced electrochemical surface area, (ii) optimized mass transport pathways through engineered porosity, and (iii) preserved structural integrity via a continuous conductive framework, collectively enabling significant Ir loading reduction without compromising catalytic layer performance. Fundamental mechanistic investigations further disclose that Nd doping induces critical interfacial Nd-O-Ir configurations that stabilize lattice oxygen, together with intensified electron effect among mixed valent Ir that inhibits the overoxidation of Ir active sites during the OER process, synergistically ensuring enhanced catalytic durability. Our work establishes a dual-modulation paradigm integrating nanoscale architectural engineering with atomic-level heteroatom doping, providing a viable pathway toward high-performance PEMWE systems with drastically reduced noble metal requirements.

DOI: 10.1016/j.cjsc.2025.100600

Source: http://cjsc.ac.cn/cms/issues/795