The influence of three different transition metals (Me = Fe, Co, Cu) on the oxygen reduction reaction (ORR) kinetics in acidic medium of Me–N–C catalysts synthesized using Me­(II)-phthalocyanine as precursors is investigated in this work. Through a detailed electrochemical characterization using cyclic voltammetry and rotating ring-disk electrode, several kinetic parameters such as Tafel slope, reaction order for oxygen and proton, apparent activation energy, selectivity toward hydrogen peroxide production, and kinetics of reduction of adsorbed oxygen were determined. The behavior of these three catalysts is analyzed in detail. A comparison between each other of the catalysts, and with a Pt-based catalyst is done. The results obtained provide clear evidence of the important role played by each transition metal in the formation of more or less effective active sites. The ORR kinetics behavior can be well interpreted according to the occurrence of a redox-mediated coverage of the active sites at low overpotentials (close to the ORR onset), which has influence on the Tafel slope, as well as on the oxygen adsorption and activation energy of the process. The results clearly show that, among the other transition metals considered, Fe is the best performing one in carrying out the ORR.

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A Fe-N-C non-noble metal (NNM) catalyst for oxygen reduction reaction (ORR) catalyst was prepared via hard templating method using Fe(II)-phthalocyanine. Its electrochemical behavior towards the ORR was tested in alkaline conditions using cyclic voltammetry (CV) and rotating disk electrode (RDE) techniques. The kinetics of the reduction of the adsorbed oxygen, the selectivity, and the activity towards hydrogen peroxide reduction reaction (HPRR), were investigated. The ethanol tolerance and the stability in alkaline conditions were also assessed with the purpose to verify the good potentiality of this catalyst to be used in an alkaline direct ethanol fuel cell (DEFC). The results evidence that the ORR occurs mainly following the direct 4 ereduction to OH-, and that the Fe-N-C catalysts is highly ethanol tolerant with a promising stability. The alkaline DEFC tests, performed after the optimization of the ionomer amount used for the preparation of the catalyst ink, show good results at low-intermediate currents, with a maximum power density of 62 mW cm-2. The initial DEFC performance can be partially recovered after a purge-drying procedure. Keywords Fe(II)phthalocyanine; rotating disk electrode; anion exchange membrane fuel cell; stability; hydrogen peroxide reduction; cyclic voltammetry. Highlights  The ORR kinetics of a Fe-N-C catalyst was investigated using cyclic voltammetry  Fe-N-C catalyst is more active towards O 2 reduction than H 2 O 2 reduction  Fe-N-C catalyst is ethanol tolerant and shows good durability in RDE  Performance of alkaline DEFC varies using different ionomer wt. % at cathode  Short-term DEFC durability was preliminary assessed