▎ 摘　　要

Oxygen reduction reaction (ORR) is important for energy and catalytic applications. Therefore, it is significant to develop highly active and selective catalysts to promote ORR. According to the reaction process, ORR can be categorized into two- and four-electrons transfer pathways. In this work, chemically modified graphene sheets with different defects were used as precursors, which were integrated with Ag-7,7,8,8-tetracyanoquinodimethane (Ag-TCNQ) to form hybrid catalysts. The ORR activities of Ag-TCNQ/high defect graphene and Ag-TCNQ/low defect graphene were compared. The results show that the electron transfer number of ORR with Ag-TCNQ/high defect graphene is 2.4. And its corresponding production yield of H2O2 is 0.62 mg/h, and Faraday efficiency is 64.45%. In comparison, the electron transfer number of ORR with Ag-TCNQ/low defect graphene is 3.7 and the corresponding half-wave potential is about 0.7 V (vs. RHE). Therefore, high structural defects promote the two-electron process of ORR, while low structural defects facilitate the four-electron process of ORR. In the composites, Ag-TCNQ nanoparticles and graphene have formed a hybrid effect to improve the catalytic activities.