EDTA-derived CoNC and FeNC electro-catalysts for the oxygen reduction reaction in acid environment

Here, in-house CoNC and FeNC have been prepared by, first, chelating the metals (Co or Fe) with ethylene diamine tetra acetic acid, known as EDTA (nitrogen precursor). UV-Visible (UV-Vis) spectrometry has been used to ensure the chelated metal formation. In the next step, the chelated metals have been deposited on a high surface area oxidized carbon support to increase the electrical conductivity. The latter composite material has been thermally treated at 800 °C (CoNC8 and FeNC8) or 1000 °C (CoNC10 and FeNC10) in nitrogen atmosphere in order to create the catalytic sites that will be able to perform the oxygen reduction reaction (ORR) in the acid medium. Electrochemical tests have been carried out to investigate the activity and durability of the electro-catalysts for the ORR. Methanol tolerance properties have been also evaluated for a possible application in direct methanol fuel cells. It appears that FeNC8 is the most active electrocatalyst in the presence of methanol in the base electrolyte, thus showing promising characteristics for direct methanol fuel cells. Instead, stability tests of these metal nitrogen catalysts indicate the best resistance to corrosion for the catalysts treated at 1000 °C.