An overview of noncarbon support materials for membrane electrode assemblies in direct methanol fuel cells: Fundamental and applications

Noncarbon support materials (NCSMs) used in the membrane electrode assemblies (MEAs) have received extensive attentions due to their better chemical stability, excellent corrosion resistance and high electrical conductivity. To develop high-quality MEA, great efforts have been devoted to improving the electrochemical performance and durability of MEAs through the surface engineering of NCSMs. With this context, the recent progress of the NCSMs as catalyst support and diffusion layer is summarized. The functional mechanisms and critical roles of NCSMs in MEAs are firstly discussed in terms of the structure-functions relationship. The design strategies and fabrication process based on different noncarbon materials (e.g., metal-based materials and carbides) as catalyst supports are summarized from the perspective of nanoscale structures like nanoparticles, nanofibers, and nanotubes. The structural design and surface modification of the noncarbon materials applied to the diffusion layer and stack-level MEA are also analyzed. Finally, the current limitations, prospective and future development tendency of NCSMs in MEA are proposed. This review is believed to provide an in-depth overview and promising research directions for the design of catalyst supports in fuel cells.