Study On Iron-based Catalytic Materials Used In The Air Electrode

Investigation was carried out to synthesize Fe-O/C and Fe-S/C material for their application as catalysts for oxygen reduction and oxygen evolution in alkaline media.M-O/C (M=Fe, Ni) were synthesized using method of microwave sintering. The Fe-O/C has good electrocatalytic ability towards ORR, the current density increased obviously to86mA cm-2at potential of-0.2V versus an Hg/HgO reference electrode. The product was Fe2O3/C by XRD analysis. Electrode is very stable when at the potential of-0.2V, the current density maintain to70mA cm-2and at the potential of0.6V, the current density maintain to37mA cm-2.Fe-O/C was prepared using method of solid-phase combustion, the optimal pyrolyzed temperature and time were observed at600℃and3h. The product was hematite type of Fe2O3/C, The particles were irregular spherical with the size of10to30nm and dispersed uniformly. In alkaline electrolyte with reference potential of0.6V(vs. HgO/Hg), current density of catalytic OER under air condtion, was147mA cm-2. The electrode showed excellent electrocatalytic abilitytowards OER.Fe-S/C was prepared using method of microwave sintering. The product was Pyrite type of FeS2/C, The particles were irregular spherical with the size of10to30nm and dispersed uniformly. In alkaline electrolyte with reference potential of0.6V(vs. HgO/Hg), current density of catalytic OER under condtions of air, was300mA cm-2. The electrode showed superior electrocatalytic ability towards OER. It suggests Fe-O/C prepared using method of solid-phasecombustion and Fe-S/C prepared using method of microwave sintering have higher performance on catalytic OER than the precious metal5wt%Pt/C catalyst, and therefor it can act as catalytic mater-ial of bifunctional oxygen electrode.