Durable, pure water–fed, anion-exchange membrane electrolyzers through interphase engineering
- Shujin Hou
- Archana Sekar
- Yang Zhao
- Minkyoung Kwak
- Juhyun Oh
- Kelvin Kam-Yun Li
- Peiyao Wu
- Ryan T. Hannagan
- Valeria Cartagena
- Anthony C. Ekennia
- Hui Duan
- Michael J. Zachman
- Joelle Frechette
- Gregory M. Su
- Balsu Lakshmanan
- Yushan Yan
- Thomas F. Jaramillo
- Shannon W. Boettcher
2025-10-17
Anion-exchange membrane water electrolyzers (AEMWEs) promise scalable, low-cost hydrogen production but are limited by the electrochemical instability of their anode ionomers. We report interphase engineering using inorganic-containing molecular additives that coassemble with ionomer, enabling pure water–fed AEMWEs to operate with a degradation rate <0.5 millivolt per hour at 2.0 amperes per square centimeter and 70°C—a >20-fold durability improvement. Analysis of different additives and ionomers shows that the stabilization mechanism involves cross-links between metal oxo/hydroxo oligomers and ionomers. Under operation, the inorganic additive enriches, forming an interphase near the water-oxidation catalyst that passivates the anode ionomer against continuous degradation while maintaining mechanical integrity and hydroxide conductivity. This additive-based interphase-engineering strategy provides a path to durable AEMWEs that operate without supporting electrolytes and is adaptable across diverse catalysts and ionomers for electrochemical technologies.