Enhancing the performance of unitized regenerative proton exchange membrane fuel cells through microwave-synthesized chitosan based nanocomposites.

The membrane electrode assembly (MEA) is a core component of unitized regenerative proton exchange membrane fuel cells (UR-PEMFCs). The studies aimed to improve the cell performance and reduce the cost of the MEAs for the widespread adoption of UR-PEMFCs. The present study focuses on modifications of MEA. For this purpose, an innovative nanocomposite electrocatalyst was developed by using a carbon-based support material containing platinum nanoparticles with a diameter of approximately 20-30 nm via microwave synthesis technique. The electrocatalyst was developed by a single-step process, consist of multi-walled carbon nanotubes (MWCNT), graphitic carbon nitride (g-CN), chitosan (Chi), and platinum nanoparticles (MWCNT/g-CN/Chi/Pt nanocomposite). With the development of this support material, a relatively economical and effective electrocatalyst was obtained by large surface area and using the platinum on this surface at the nano level. The prepared catalyst was applied to commercially available membrane electrode assemblies with an active area of 100 cm. Single-cell and triple-stack performance tests were conducted, and an increase of 17.13 % in the electrolyzer mode and 16.98 % in the fuel cell mode was achieved in single-cell performance with this applied electrocatalyst. Furthermore, an enhancement of 16.96 % in the electrolyzer mode and 16.81 % in the fuel cell mode was discerned in the UR-PEMFC stack. Beside the experimental studies, a numerical model of the modified membrane properties has been developed and validated through experimental data.