Elucidating the degradation behavior of a 25 cm2 pure-water-fed non-precious metal anion exchange membrane water electrolyzer cell

Abstract

Anion exchange membrane water electrolysis (AEMWE) has become a promising technology for generating hydrogen in a carbon-neutral economy. However, its competitiveness is currently limited by the low durability of AEMWE systems. To increase its durability and to advance its industrial application, this study examines the degradation behavior of a 25 cm2 AEMWE cell utilizing non-precious metal catalysts and pure water feed in a short-term durability test. Polarization curves and electrochemical impedance spectroscopy, along with scanning electron microscopy and energy-dispersive X-ray spectroscopy, are employed to identify factors affecting cell efficiency and stability. The pure-water-fed AEMWE cell exhibits high performance losses and low stability that is mainly related to degradation in the anode and at the interface of anode and membrane. Ionomer degradation, reducing hydroxide ion conductivity, and mechanical stability of the catalyst layer, is identified as the key factor decreasing cell efficiency and stability during pure water operation. The findings aim to guide the development of strategies to enhance cell performance and durability of pure-water-fed AEMWE.