Synthesis and Performance of CoSeO_3 Compound as a Cathodic Catalyst for Oxygen Reduction

Novel CoSeO3 nanoparticles were successfully synthesized by low temperature refluxing method using dodecacarbonyltetracobalt [Co4(CO)12] and selenium(Se) as raw materials in glycol solvent.The crystalline structure,morphology and electrochemical performances of the as-prepared product were characterized by scanning electron microscope(SEM),X-ray diffraction(XRD) and rotating disk electrode(RDE) technique.Results show that the as-obtained CoSeO3compound presents the structural characteristics of monoclinic CoSeO3 H2O with the particle size of 26.7 nm and regular figure.The catalyst demonstrates significant electrocatalytic activity towards oxygen reduction reaction(ORR),showing an open circuit potential(OCP) of 0.80 V(vs NHE) in 0.5 mol/L H2SO4 solution at 25℃.The transfer process of about 3.8 electrons is determined during the reduction per oxygen molecule by using Koutecky-Levich equation.The transfer coefficient,Tafel slope and exchange current density are 0.50,119 mV and 1.98×10-6 mA/cm2 in the potential region of 0.64–0.76 V(vs NHE),respectively.The catalytic activity and electrochemical stability of the catalyst are compared with a commercial Pt catalyst.