Architected Porous Media for Fuel Cells, Electrolyzers and Beyond: A Paradigm for Transport Engineering

Abstract Electrochemical energy conversion and storage technologies such as fuel cells, electrolyzers, and batteries are increasingly limited by the transport of reactants, products, charge, and heat through porous structures. While advances in catalysts and materials have significantly improved device performance, porous media have largely remained stochastic in nature, with transport properties emerging as consequences of fabrication rather than deliberate design. Recent developments in advanced manufacturing, characterization, and computational optimization are enabling the creation of architected porous media with increasingly controllable transport behavior. In this perspective, we introduce a ”transport-by-design” framework in which effective transport properties, including diffusivity, permeability, conductivity, and capillary transport, as well as electrochemically active surface area in reactive porous media, become explicit design targets rather than emergent outcomes. We discuss how architected porous media can provide enhanced control over these properties through graded, hierarchical, anisotropic, and topology-optimized structures and highlight emerging opportunities across electrochemical devices. We argue that designing porous architectures from targeted transport requirements represents an emerging shift from material-centric approaches toward transport-informed engineering as a guiding principle for next-generation electrochemical energy conversion and storage technologies.