Buffering the Active State for Proton Exchange Membrane Water Electrolysis

Area of Science:

• Electrochemistry
• Materials Science
• Catalysis

Background:

• Proton exchange membrane water electrolysis (PEMWE) is crucial for renewable hydrogen production.
• Commercialization requires catalysts with high activity, durability, and low noble-metal loading under acidic oxygen evolution reaction (OER) conditions.
• Catalyst failure stems from active state disruption due to redistribution, degradation, oxidative stress, and proton imbalance.

Purpose of the Study:

• To propose a catalyst-centered design framework targeting root causes of active state disruption.
• To classify buffering strategies for sustaining catalyst active states during PEMWE operation.
• To provide a roadmap for designing durable and active PEMWE catalysts.

Main Methods:

• Review and synthesis of existing research on PEMWE catalyst degradation mechanisms.
• Development of a classification system for catalyst buffering strategies.
• Analysis of design approaches for iridium (Ir), ruthenium (Ru), and non-platinum group metal (PGM) anodes.

Main Results:

• Identified coupled processes driving catalyst failure: active-species redistribution, oxygen-framework degradation, oxidative stress, proton-transfer imbalance, and mechanistic drift.
• Classified buffering strategies into five categories: mobility/topology, oxygen-framework, electron, proton-water-ion programming, and mechanistic dial.
• Demonstrated rational design pathways for buffered active states in various anode materials.

Conclusions:

• A catalyst-centered framework effectively addresses active state stability in PEMWE.
• Buffering strategies are essential for enhancing catalyst durability and performance.
• This work provides a roadmap for developing next-generation PEMWE catalysts for efficient hydrogen production.