Non-Iridium-Based Electrocatalysts for the Acidic Oxygen Evolution Reaction: Progress and Perspectives.

Area of Science:

• Electrochemistry
• Materials Science
• Catalysis

Background:

• The oxygen evolution reaction (OER) in acidic media is a critical bottleneck for proton exchange membrane water electrolysis (PEMWE).
• Iridium-based catalysts offer high performance but are scarce and expensive, driving research into alternatives.
• Harsh acidic conditions lead to catalyst degradation, limiting long-term operation.

Purpose of the Study:

• To review recent advances in non-iridium-based catalysts for acidic OER.
• To explore strategies for enhancing catalyst activity and durability.
• To discuss the importance of understanding reaction mechanisms and optimizing electrolyzer design.

Main Methods:

• Review of recent literature on non-Ir catalysts (Ru-based, oxides, metal-free).
• Discussion of catalyst engineering strategies (defect engineering, doping, interface modulation, high-entropy design).
• Emphasis on in situ/operando characterization techniques for mechanistic insights.

Main Results:

• Non-Ir catalysts show promise through various engineering strategies.
• Tuning electronic structures improves performance and stability.
• Understanding active sites and intermediates is key to mechanistic elucidation.

Conclusions:

• Continued development of non-Ir catalysts is essential for cost-effective PEMWE.
• AI-driven screening and optimized electrolyzer design will accelerate progress.
• Sustainable seawater electrolysis offers a pathway for large-scale green hydrogen production.