Analysis of PEM Water Electrolyzer Failure Due to Induced Hydrogen Crossover in Catalyst-Coated PFSA Membranes

Abstract

Polymer electrolyte membrane water electrolysis (PEMWE) is a leading candidate for the development of a sustainable hydrogen infrastructure. The heart of a PEMWE cell is represented by the membrane electrode assembly (MEA), which consists of a polymer electrolyte membrane (PEM) with catalyst layers (CLs), flow fields, and bipolar plates (BPPs). The weakest component of the system is the PEM, as it is prone to chemical and mechanical degradation. Membrane chemical degradation is associated with the formation of hydrogen peroxide due to the crossover of product gases (H2 and O2). In this paper, membrane failure due to H2 crossover was addressed in a membrane-focused accelerated stress test (AST). Asymmetric H2O and gas supply were applied to a test cell in OCV mode at two temperatures (60 °C and 80 °C). Electrochemical characterization at the beginning and at the end of testing revealed a 1.6-fold higher increase in the high-frequency resistance (HFR) at 80 °C. The hydrogen crossover was measured with a micro-GC, and the fluoride emission rate (FER) was monitored during the ASTs. A direct correlation between the FER and H2 crossover was identified, and accelerated membrane degradation at higher temperatures was detected.

A new insight into the chemical degradation of proton exchange membranes in water electrolyzers

“…34 H 2 O 2 can further decompose into HO˙ radicals via reactions 2–4. 35 Moreover, the FRR levels in the CeO 2 -doped MEAs were reduced even when CeO 2 was only doped on one side. This suggests that the formation of free radicals in both electrodes is not completely independent.…”

Recent advancements in catalyst coated membranes for water electrolysis: a critical review

“…Kuhnert et al studied the degradation mechanisms in PEM water electrolysers, emphasizing the adverse effects of hydrogen crossover on membrane integrity. 108 Highlighting a membrane-focused accelerated stress test (AST), the study reveals that higher temperature significantly increase hydrogen crossover, resulting in accelerated membrane degradation evidenced by increased high-frequency resistance (HFR) and fluoride emission rates (FER). These findings highlight the critical need for optimized operational conditions and advanced membrane materials to enhance the durability and reliability of PEM systems.…”

A Survey on Anomalies and Faults that may Impact the Reliability of Renewable-based Power Systems

“…Impurities could also result in membrane degradation [84,85], often due to catalyst corrosion [86]. Moreover, radical attacks are responsible for membrane degradation [80]: the phenomenon is more promoted for low current density [87,88], since a faster membrane thinning could be observed [89]. It is however worth noting that temperature effect is more severe with respect to the operative current density [88].…”

“…Moreover, radical attacks are responsible for membrane degradation [80]: the phenomenon is more promoted for low current density [87,88], since a faster membrane thinning could be observed [89]. It is however worth noting that temperature effect is more severe with respect to the operative current density [88]. Catalyst degradation is a very slow process, thus is not responsible for sudden cell failure.…”