Electrocatalytic activities of REMn2O5 (RE = Dy, Ho, Er, Tm, Yb, and Lu) and Er0.76Zr 0.11Ca0.13Mn2O5 for oxygen reduction in alkaline solution

A series of complex oxides REMn2O5 (RE=Dy, Ho, Er, Tm, Yb, and Lu) and Er0.76Zr0.11Ca0.13Mn2O5 with large specific areas and nanoscale grain sizes were prepared by an improved amorphous citric precursor method (IACP). Their electrocatalytic performances were characterized by the polarization curves of gas diffusion electrodes employing the oxides. The measurement of polarization curves indicated that the REMn2O5 containing different rare earth showed a obviously different electrocatalytic performances for oxygen reduction reaction, being the order Tm>Er>Ho>Dy>Lu>Yb. Temperature-programmed reduction (TPR) analysis revealed that the REMn2O5 containing different rare earth showed a significantly different oxygen contents and TPR peak temperatures. Their catalytic activities depended on both the oxygen contents and TPR peak temperatures. These two factors play a plus and a minus role respectively.