Constructing Robust 3D Ionomer Networks in the Catalyst Layer to Achieve Stable Water Electrolysis for Green Hydrogen Production

Han Liu; Yang Yang; Jiawei Liu; Meiquan Huang; Kejie Lao; Yaping Pan; Xinhui Wang; Tian Hu; Linrui Wen; Shuwen Xu; Shuirong Li; Xiaoliang Fang; Wen-Feng Lin; Nanfeng Zheng; Hua Bing Tao

doi:10.1021/acsami.4c03318

Constructing Robust 3D Ionomer Networks in the Catalyst Layer to Achieve Stable Water Electrolysis for Green Hydrogen Production

ACS Appl Mater Interfaces. 2024 Apr 3;16(13):16408-16417. doi: 10.1021/acsami.4c03318. Epub 2024 Mar 19.

Authors

Han Liu^{1

2}, Yang Yang^{1

2}, Jiawei Liu^{1

2}, Meiquan Huang^{1

2}, Kejie Lao^{1

2}, Yaping Pan^{1

2}, Xinhui Wang^{1

2}, Tian Hu^{1

2}, Linrui Wen², Shuwen Xu^{1

2}, Shuirong Li³, Xiaoliang Fang³, Wen-Feng Lin⁴, Nanfeng Zheng^{1

2}, Hua Bing Tao^{1

2}

Affiliations

¹ State Key Laboratory for Physical Chemistry of Solid Surfaces, Collaborative Innovation Center of Chemistry for Energy Materials, and College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, China.
² Innovation Laboratory for Sciences and Technologies of Energy Materials of Fujian Province (IKKEM), Xiamen 361005, China.
³ College of Energy, Xiamen University, Xiamen 361005, China.
⁴ Department of Chemical Engineering, Loughborough University, Loughborough LE11 3TU, Leicestershire, U.K.

PMID: 38502312
DOI: 10.1021/acsami.4c03318

Abstract

The widespread application of proton exchange membrane water electrolyzers (PEMWEs) is hampered by insufficient lifetime caused by degradation of the anode catalyst layer (ACL). Here, an important degradation mechanism has been identified, attributed to poor mechanical stability causing the mass transfer channels to be blocked by ionomers under operating conditions. By using liquid-phase atomic force microscopy, we directly observed that the ionomers were randomly distributed (RD) in the ACL, which occupied the mass transfer channels due to swelling, creeping, and migration properties. Interestingly, we found that alternating treatments of the ACL in different water/temperature environments resulted in forming three-dimensional ionomer networks (3D INs) in the ACL, which increased the mechanical strength of microstructures by 3 times. Benefitting from the efficient and stable mass transfer channels, the lifetime was improved by 19 times. A low degradation rate of approximately 3.0 μV/h at 80 °C and a high current density of 2.0 A/cm² was achieved on a 50 cm² electrolyzer. These data demonstrated a forecasted lifetime of 80 000 h, approaching the 2026 DOE lifetime target. This work emphasizes the importance of the mechanical stability of the ACL and offers a general strategy for designing and developing a durable PEMWE.

Keywords: PEM water electrolysis; anode catalyst layer; stability in hydrogen production; thermal and water cycles; three-dimensional ionomer networks.