▎ 摘　　要

In this study, a novel electrocatalyst based on graphene quantum dots (GQDs)-supported manganese oxide (Mn3O4) and silver (Ag) (denoted as GQDs/ Mn3O4/Ag) is fabricated through the electrodeposition method, and its performance is examined toward oxygen reduction reaction (ORR). Electrochemical investigations reveal that the ORR mechanism on the fabricated catalyst forward through a four-electron transfer pathway which is identified as that of the 20% Pt/C. The prepared GQDs/Mn3O4/Ag-carbon paper (CP) presents comparable ORR performance to 20% Pt/C. It exhibits superior durability during the operation time even greater than 20% Pt/C. GQDs/Mn3O4/Ag-CP retains 94.4% of its activity after 10 000 s operation time which is much better than that of 20% Pt/C (84.7%). In addition, the better performance of GQDs/Mn3O4/ Ag-CP (I: -5.63 mA.cm(-2)) in comparison with Mn3O4/Ag-CP (I: -4.74 mA. cm(-2)), GQDs/Mn3O4-CP (I: -4.63 mA.cm(-2)), GQDs/Ag-CP (I: -3.51 mA. cm(-2)), and GQDs-CP (I: -2.87 mA.cm(-2)) indicates that the constructed electrocatalyst with unique properties facilities the ORR kinetics.