Advanced Electrode Materials for Water Electrolysis: Design Principles, Performance Trade-Offs, and Technology Pathways Across ALK, PEM, SOEC, and AEM Systems

Abstract

Highlights What are the main findings?1. Rapid growth of research on electrode materials for water electrolysis technologies between 2021 and 2025. 2. Transition-metal-based catalysts and heterostructured materials show promising activity comparable to noble-metal catalysts. 3. Each electrolysis technology (ALK, PEM, SOEC, AEM) requires specific electrode materials due to different operating environments and reaction mechanisms. What are the implications of the main findings?1. Advanced catalyst design and interface engineering can significantly improve electrolysis efficiency and durability. 2. Reducing noble metal loading is essential for lowering electrolyzer costs and enabling large-scale hydrogen production. 3. Integrated materials research and system-level optimization will be critical for accelerating the commercialization of green hydrogen technologies. Abstract The transition toward low-carbon energy systems has intensified interest in sustainable hydrogen production technologies. One of the most promising methods for producing green hydrogen is water electrolysis powered by renewable energy. This work reviews recent advances in electrode materials used in four major electrolysis technologies: alkaline (ALK), proton exchange membrane (PEM), solid oxide electrolysis cells (SOEC), and anion exchange membrane (AEM). A bibliometric analysis of scientific publications from 2021 to 2025 highlights the rapid growth of research and the increasing importance of electrode materials in improving electrolysis performance. Operating environments, material requirements, and catalytic properties are compared across these systems. Recent developments in electrocatalysts-including transition-metal alloys, heterostructured catalysts, defect-engineered materials, and nanostructured systems-are evaluated in terms of catalytic activity, durability, and scalability. Particular attention is given to reducing noble metal usage while maintaining high electrochemical performance. Results indicate that transition-metal-based catalysts and engineered interfaces can achieve activity comparable to noble-metal systems while offering better cost efficiency.