▎ 摘　　要

Manganese-based oxides are promising as a cost-effective replacement of precious-metal electrocatalysts for oxygen reduction reaction (ORR). Herein, we designed a high-performance Mn3O4 nanoparticles supported on three-dimensional graphene with interconnected hierarchical porous structure by a hydrothermal method, in which coal tar pitch and CaCO3 were used as the carbon precursor and the template, respectively. The as-prepared Mn3O4/3DHG with micropore, mesopore and macropore structure of graphene exhibited more defects and exposed more active sites, which was favorable to improve the electrocatalytic performance. Mn3O4/3DHG showed a higher half-wave potential (0.833 V vs RHE) than 20 wt% Pt/C (0.828 V vs RHE). The accelerated durability tests exhibited half-wave potential of Mn3O4/3DHG shifted by an 18 mV drop after 5000 cycles of cyclic voltammetry scanning, which was smaller than that of 20 wt% Pt/C (8 mV). The electrochemical test results revealed that Mn3O4/3DHG had better catalytic ORR performance than 20 wt% Pt/C.