Electrocatalytic Activity of Post Pyrolysis Plasma treated BPC FeGly for the Oxygen Reduction Reaction

The design and fabrication of electrocatalysts for oxygen reduction reaction (ORR) with high performance at low cost remains a crucial challenge for the commercialization of fuel cells. In order to replace the Pt and Pt alloy based electrocatalysts, metal nitrides and Metal Carbon Nitrogen (MNC), metal free heteroatom doped carbon material and plasma treated material were found to have interesting ORR properties. The enhanced active site formation, O₂ adsorption of the catalyst, electrical conductivity of the surface modified carbon based (MNC) catalysts have shown promising activity that closely matches the oxygen reduction activity of Pt in acidic and alkaline media.In order to improve ORR activity in acidic medium, we prepared MNC based ORR electrocatalysts by coupling of simple mechanomilling method and post pyrolysis plasma treatment of BPC FeGly catalysts. The plasma treatment for BPC-Fe-Gly is an added approach leads to increase in number of oxygen adsorption sites of the catalyst and improve the electrical conductivity by N doping and defects generation by surface modification. The electrochemical properties of as prepared material was studied by cyclic voltammetric measurements which show that the untreated BPC- FeGly has an ORR onset potential of 0.73 V vs RHE whereas BPC- FeGly after treatment in N₂ cold plasma showed 0.79 V vs RHE. Based on our previous reported results, we attribute the increase in activity largely to the formation of highly active nitrogen sites and to the promotion of electron transport in the ORR process by these dopants. Accordingly, N₂ plasma treated BPC FeGly exhibits enhanced ORR performance with only 70 mV shift in half wave potential when compared to 20% Pt-C in 0.5 M H₂SO₄. The structural properties of these materials were evaluated by XRD analysis and the catalysts morphology was characterized by SEM and EDS.