PBO-based carbon micro-nanofiber paper as catalyst carrier for fuel cell catalytic layer

Traditionally, the catalyst layer was formed by spraying a slurry of catalyst, carbon black, and ionomer onto the proton exchange membrane of cells, leading to the catalyst distributed unevenly and the catalytic activity reduced. This study then avoids the slurry spraying process and uses PBO fibrillated fibers to create an integrated self-supporting and effectively dispersing catalyst layer. Detailed experimental results show that nitrogen doping increases the specific surface area by 32.3 % and tensile strain by 25.4 %, with negligible impact on the graphitization of activated carbon paper. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) analyses confirm the in-situ formation of ORR-active platinum catalysts on the electrode surface. Additionally, it was demonstrated that Pt particles formed by thermal reduction at 700 °C have an average size of 2.2 nm. The self-supporting catalyst layer, loaded with Pt catalysts on nitrogen-doped activated carbon paper with a beating degree of 45 °SR, exhibited the smallest Tafel slope (87.1 mV·dec -1 ). Nitrogen doping enhances the electrochemical performance of activated carbon paper, providing superior Pt loading capacity and catalytic efficiency. This new strategy for the high-performance catalyst layer has potential application in the proton exchange membrane fuel cells.