Green Hydrogen Goes Affordable: Rethinking Catalyst Design

This schematic illustrates the comprehensive framework for advancing non-noble metal catalysts in acidic oxygen evolution reactions (OER). It highlights three core research questions—mechanism of activity expression, causes of poor stability, and strategies for stability improvement—alongside six key catalyst categories

Newswise.com & Chinese Academy of Sciences | 15-Aug-2025

As the world pivots toward carbon neutrality, hydrogen has emerged as a clean, versatile energy carrier. Among various production pathways, proton exchange membrane water electrolyzers (PEMWE) are favored for delivering high-purity hydrogen using renewable electricity. However, widespread deployment is hindered by the use of iridium and ruthenium—noble metals that are both scarce and prohibitively expensive. While non-precious metal alternatives show promise, they struggle to meet the combined activity and durability requirements for acidic oxygen evolution reaction (OER). These shortcomings in both performance and long-term stability underscore the urgent need for deeper investigation into novel design strategies and degradation mechanisms to enable practical implementation of non-noble metal catalysts (NNMCs).

A collaborative research team from the Changchun Institute of Applied Chemistry, Chinese Academy of Sciences has published (DOI: 10.1016/j.esci.2024.100295) a comprehensive review in eScience (February 2025), examining noble metal-free electrocatalysts for acidic water oxidation. The article investigates both fundamental and applied aspects of non-precious metal catalysts for practical application in PEMWE systems. Through a deep dive into catalytic pathways, stability concerns, and material innovations, the review offers fresh insights into building cost-effective and durable alternatives to noble metals in hydrogen energy technologies.

The study begins by dissecting the key mechanistic pathways of acidic oxygen evolution, focusing on two major routes: water hydrogen atom abstraction (WHAA) and direct coupling mechanism (DCM). These processes involve complex intermediate steps that are sensitive to surface structure and electronic configuration. The authors argue that understanding these mechanisms is essential for guiding rational catalyst design. However, conventional thermodynamic models fall short in capturing real-time kinetics, emphasizing the need for in situ characterization and molecular simulations.

Beyond activity, the review identifies stability as a critical hurdle. Noble metal-free catalysts often degrade under acidic conditions due to metal ion dissolution or irreversible oxidation. To address this, researchers have devised innovative strategies: self-healing catalysts that regenerate active components, incorporation of acid-stable metal oxide phases, and doping with high-oxidation-potential anions. The review highlights several recent breakthroughs—such as Co–Mn oxides, F-doped MnO₂, and high-entropy alloys—that demonstrate both strong OER activity and enhanced durability. These developments suggest that with the rational structural and electronic tuning, NNMCs can deliver performance comparable to traditional noble metal catalysts in real-world electrolysis systems....more
https://www.newswise.com/articles/green-hydrogen-goes-affordable-rethinking-catalyst-design

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