Research progress on components and design variables in electrochemical hydrogen compressor: an analytical review

The global challenge of reducing greenhouse gas emissions has driven the development of clean energy technologies, with hydrogen emerging as a key vector for decarbonization. However, its low volumetric density poses significant challenges for efficient compression and storage. In this context, electrochemical hydrogen compressors (EHCs) have emerged as a promising alternative to traditional mechanical systems, offering high energy efficiency, operation without movement of parts, and simultaneous purification capabilities. This review explores the operational principles of EHCs and provides a detailed analysis of their critical components, with particular emphasis on the membrane-electrode assembly (MEA), including polymer membranes and electrocatalysts. The most relevant advances between 2020 and 2025 are systematized, comparing structural properties, electrochemical performance, and novel materials efficiency. Among the key findings, it is highlighted that thin and reinforced membranes enhance energy performance, while bimetallic or non-noble catalysts offer viable solutions to the high cost of platinum. This analysis identifies emerging technological trends and provides clear guidelines for the design of more efficient, durable, and scalable EHC systems. © The Author(s) 2025.