Yang Chenlu, Zhu Yanping, Zhang Fengru, Yao Longping, Chen Yihe, Lu Tongchan, Li Qixuan, Li Jun, Wang Guoliang, Cheng Qingqing, Yang Hui
Shanghai Advanced Research Institute, Chinese Academy of Sciences, Shanghai, 201210, China.
University of the Chinese Academy of Sciences, Beijing, 100039, China.
Adv Mater. 2025 Jun 23:e2507560. doi: 10.1002/adma.202507560.
Achieving high activity and stability while minimizing Ir usage poses a significant challenge in the industrialization of proton exchange membrane water electrolysis (PEMWE). Herein we report a sulfur-doping strategy that enables the OER pathway on IrO nanoparticles (IrO/S) to switch from conventional adsorption evolution mechanism (AEM) to lattice oxygen mechanism (LOM) while maintaining Ir─O bond stability, thus achieving a significant enhancement in both intrinsic activity and durability. Advanced spectroscopies and theoretical calculations reveal that the Ir─S coordination motif within the lattice increases the electron density of the Ir center and enhances Ir─O covalency, thus triggering the LOM pathway. Importantly, the lattice distortion and unsaturated Ir─O coordination within the IrO/S generate the oxygen nonbonding state that acts as an electron sacrificial agent to preserve Ir─O bonds upon the LOM-dominated OER process. As a result, PEMWE integrated with such IrO/S electrocatalyst delivers a low cell voltage (1.769 V at 2.0 A cm) and long-term stability (16.6 µV h⁻¹ over 1000 h@1.0 A cm⁻) while dramatically reducing Ir usage from 1.0 to 0.3 mg cm. This work establishes S doping as a viable strategy to trigger LOM and stabilize lattice oxygen redox in Ir-based catalysts, opening a new avenue for low-Ir PEMWEs.
在质子交换膜水电解（PEMWE）的工业化过程中，在尽量减少铱使用量的同时实现高活性和稳定性是一项重大挑战。在此，我们报道一种硫掺杂策略，该策略能使氧化铱纳米颗粒（IrO/S）上的析氧反应（OER）途径从传统的吸附演化机制（AEM）转变为晶格氧机制（LOM），同时保持Ir─O键的稳定性，从而在本征活性和耐久性方面都实现显著提高。先进的光谱学和理论计算表明，晶格内的Ir─S配位基序增加了Ir中心的电子密度并增强了Ir─O共价性，从而触发了LOM途径。重要的是，IrO/S内的晶格畸变和不饱和Ir─O配位产生了氧非键合状态，该状态在以LOM为主导的OER过程中充当电子牺牲剂以保护Ir─O键。结果，集成这种IrO/S电催化剂的PEMWE具有低电池电压（在2.0 A cm时为1.769 V）和长期稳定性（在1.0 A cm⁻下1000小时内为16.6 µV h⁻¹），同时将铱的使用量从1.0 mg cm大幅降低至0.3 mg cm。这项工作确立了硫掺杂作为一种可行的策略来触发LOM并稳定基于铱的催化剂中的晶格氧氧化还原，为低铱PEMWE开辟了一条新途径。
