Effect of WO_3 to catalytic activity of carbon supported EMD for oxygen reduction

Effect of tungsten trioxide(WO3) additive to the electrolytic manganese dioxide(EMD) catalyze oxygen reduction activity was studied.EMD composite catalysts with 5 kinds of WO3 content were prepared by ball-milling.XRD,SEM and linear vol-tage scanning and galvanostatic discharge tests were taken.Adding proper WO3 could improve the catalytic activity of EMD,the porosity of EMD was affected by WO3.Compared with the catalyst without adding WO3,the oxygen reduction potential of catalyst added WO3 was 0.02 V in advance.When the voltage was-0.15 V,oxygen reduction current of EMD,(MnO2)33(WO3)0.7,(MnO2)33(WO3)1,(MnO2)33(WO3)1.3 and (MnO2)33(WO3)1.5 was-0.21 mA,-0.35 mA,-0.85 mA,-0.53 mA and-0.08 mA,respectively,indicated that with the increasing of WO3 adding amount,the oxygen reduction current increased firstly,then decreased.The discharge platform of cell prepared with EMD,(MnO2)33(WO3)0.7,(MnO2)33(WO3)1,(MnO2)33(WO3)1.3 and(MnO2)33(WO3)1.5 was 1.05 V,1.08 V,1.21 V,1.14 V and 0.98 V,respectively.The catalytic activity was in the following order:(MnO2)33(WO3)1 (MnO2)33(WO3)1.3 (MnO2)33(WO3)0.7 EMD (MnO2)33(WO3)1.5.