Tensile straining of iridium sites in manganese oxides for proton-exchange membrane water electrolysers

Hui Su; Chenyu Yang; Meihuan Liu; Xu Zhang; Wanlin Zhou; Yuhao Zhang; Kun Zheng; Shixun Lian; Qinghua Liu

doi:10.1038/s41467-023-44483-6

Tensile straining of iridium sites in manganese oxides for proton-exchange membrane water electrolysers

Nat Commun. 2024 Jan 2;15(1):95. doi: 10.1038/s41467-023-44483-6.

Authors

Hui Su^#¹, Chenyu Yang^#², Meihuan Liu³, Xu Zhang⁴, Wanlin Zhou², Yuhao Zhang², Kun Zheng⁴, Shixun Lian⁵, Qinghua Liu⁶

Affiliations

¹ Key Laboratory of Light Energy Conversion Materials of Hunan Province College, College of Chemistry and Chemical Engineering, Hunan Normal University, Changsha, 410081, Hunan, China. suhui@hunnu.edu.cn.
² National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei, 230029, Anhui, China.
³ State Key Laboratory for Powder Metallurgy, Central South University, Changsha, 410083, Hunan, China.
⁴ Beijing Key Laboratory of Microstructure and Properties of Solids, Faculty of Materials and Manufacturing, Beijing University of Technology, Beijing, 100124, China.
⁵ Key Laboratory of Light Energy Conversion Materials of Hunan Province College, College of Chemistry and Chemical Engineering, Hunan Normal University, Changsha, 410081, Hunan, China. sxlian@hunnu.edu.cn.
⁶ National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei, 230029, Anhui, China. qhliu@ustc.edu.cn.

^# Contributed equally.

Abstract

Although the acidic oxygen evolution reaction (OER) plays a crucial role in proton-exchange membrane water electrolysis (PEMWE) devices, challenges remain owing to the lack of efficient and acid-stable electrocatalysts. Herein, we present a low-iridium electrocatalyst in which tensile-strained iridium atoms are localized at manganese-oxide surface cation sites (TS-Ir/MnO₂) for high and sustainable OER activity. In situ synchrotron characterizations reveal that the TS-Ir/MnO₂ can trigger a continuous localized lattice oxygen-mediated (L-LOM) mechanism. In particular, the L-LOM process could substantially boost the adsorption and transformation of H₂O molecules over the oxygen vacancies around the tensile-strained Ir sites and prevent further loss of lattice oxygen atoms in the inner MnO₂ bulk to optimize the structural integrity of the catalyst. Importantly, the resultant PEMWE device fabricated using TS-Ir/MnO₂ delivers a current density of 500 mA cm^-2 and operates stably for 200 h.

Grants and funding

12205300/National Natural Science Foundation of China (National Science Foundation of China)