| Résumé | In this communication, we report a novel CoPy/C catalyst for the oxygen reduction reaction(ORR) in alkaline electrolyte using cobalt sulfate heptahydrate (CoSO4·7H2O) and pyridine (Py) as the Coand N precursors supported on Vulcan XC-72R, followed by heat treatment in an inert atmosphere.Electrochemical performances were evaluated using cyclic voltammograms (CVs) and rotating diskelectrode (RDE) technique in terms of its ORR activity as a function of Co content in the catalyst synthesis.Results show that the presence of Co in the CoPy/C catalyst greatly affects the formation of ORR catalyticactive sites and that the best performing catalyst is 10%Co%30Py/C, which was synthesized at 800 °C. In 3.0mol·L-1 KOH, 10%Co30%Py/C (in O2) produces an obvious ORR current with an on-set potential at 0.014 V.Compared with the 40% Py/C the on-set potential of the 10% Co30% Py/C for oxygen reduction shiftedpositively by 71 mV (versus RHE (reversible hydrogen electrode)) and a well-defined limiting current plateauwas achieved. Therefore, a maximum current density of 1.0 mA·cm-2 was obtained at -0.16 V with ahalf-wave potential of -0.07 V. Transmission electron microscopy (TEM) measurements show that thenanoparticles with a diameter of 20 nm are uniformly dispersed on Vulcan carbon (Vulcan XC-72R). © Editorial office of Acta Physico-Chimica Sinica. |
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