Pem fuel cell electrodes: Nanofiber-based hybrid and CeO2 included electrodes for boosted performance

Official URL: https://risc01.sabanciuniv.edu/record=b2862156_(Table of contents)

PEM fuel cells have become increasingly drawn attention in numerous applications during the past decade. However, PEM fuel cells suffer from a number of drawbacks such as;the high Pt and Nafion® utilization within the electrodes exhibits a significant financial burden. Furthermore, the catalyst layer undergoes a number of side-processes during operation resulting in its deterioration and loss in performance with time. To address those issues, fiber-based electrodes were fabricated using electrospinning utilizing Pt/C as a catalyst, sulfonated silica as a proton conducting ionomer, and poly (vinylidene fluoride-trifluoroethylene) P(VDF-TrFE) as a carrier polymer. The fabricated electrodes demonstrated a functional and Nafion®-free cost-effective alternative to classically sprayed electrodes. They exhibited superior performance recording up to 417.7 mW.cm-2 maximum power density exceeding that of sprayed electrodes and fiber-based electrodes employing Nafion®. Furthermore, the aforementioned electrodes showed impressive durability against Pt-dissolution retaining up to 86.5% and exhibited a 2.6% gain in performance under C-corrosion AST. In the second part of the dissertation, CeO2-based additives were investigated to enhance the oxygen reduction reaction kinetics. Nanorod CeO2/NrGO, bare nanorod CeO2, nanocube, and nano octahedral CeO2 exhibited an overall increase in the ORR activity with octahedral CeO2 recording the highest power output (483.4 mW.cm-2). Furthermore, cerium oxide nanocube additive-based electrodes exhibited an impressive durability retaining up to 80.3% of its initial maximum power density.