A novel electrocatalyst based on Fe-ZIF-PPY nanocomposite for oxygen reduction reaction in air-breathing direct-ethanol fuel cell

The development of alcohol tolerance electrocatalysts to reduce expensive electrocatalysts has been the prospect of widespread use of alcoholic fuel cells. Therefore, the production of favorable electrocatalysts with the optimized percentage of metals and heteroatoms, enables control of electrocatalytic properties to enhance activity in the alkaline medium. In this work, Fe-ZIF-polypyrmle composite (Fe-ZIF-PPY) was carbonized under argon atmosphere, and finally, S,N-codoped carbon nanotubes containing iron nanoparticles nanocomposite (Fe-NC/S,N-CNT) was obtained. The electrocatalytic property, structure, and morphology of Fe-NC/S,N-CNT were explored via various characterization techniques (Fe-SEM, TEM, HRTEM, TGA, Raman, XRD, BET, XPS, ICP, element mapping and EDAX). Applicability of the S-doped Fe-N-C catalyst in alkaline media shows high ORR activity with sharp half-wave potential at 0.93 V (vs. RHE) and the Tafel slope of 53 mV/dec. Also, in an anion-exchange membrane direct ethanol fuel cell (AEM-DEFC) under the same conditions, two cathodes are made with the optimized electrocatalyst as MEA-1 and commercial 10 wt% Pt/C as MEA-2. The power density of 20 and 9 mW cm(-2) were obtained at 0.6 V in an air-breathing, respectively. The performance of Fe-NC/S,N-CNT catalyst was assessed optimum in DEFC. In examining the effective factors to boost the activity of the catalyst, the prominent roles of specific surface area (SSA), porosity, conductivity, and high density of active sites can be note.