Calcined Fe(III)-chelated poly(o-phenylenediamine-co-2-aminobenzenesulfonic acid) as cathode catalyst for anion-exchange membrane fuel cells

The oxygen reduction current of the cathode catalyst doped with both nitrogen and sulfur atoms is higher than that of the catalyst doped with only nitrogen atom or the catalyst doped with only sulfur atom. Nitrogen and sulfur dual-doped non-precious metal catalysts are synthesized through the pyrolysis of nitrogen- and sulfur-rich microporous polymeric precursor, specifically (poly(o-phenylenediamine- co -2-aminobenzenesulfonic acid) (P(OPD- co -SANI))). X-ray photoelectron spectroscopy (XPS) spectra reveal the presence of Fe-S bonds, pyridinic-N, pyridine-N oxide, graphitic-N, Fe-N, and pyrrolic-N within the FeNSC-900 composite. X-ray diffraction (XRD) analysis confirms a degree of graphitization in the NSC-1000, FeNC-900, FeNC-1000, FeNSC-900, and FeNSC-1000 catalysts. Scanning electron microscopy characterization indicates that the FeNSC-900 catalysts possess porous nanostructures, facilitating access to active sites essential for high oxygen reduction reaction (ORR) electrocatalytic activity. The FeNSC-900 catalyst demonstrates good electrocatalytic activity towards the ORR in KOH (aq) , with an ORR half-wave potential of 0.76 V. In a single-cell test, membrane electrode assembly (MEA) utilizing the FeNSC-900 catalyst as the cathode achieves a peak power density of approximately 213.3 mW cm −2 at 60°C, suggesting that the FeNSC-900 catalyst is a promising alternative to platinum-based catalysts in anion exchange membrane fuel cell (AEMFC) applications.