▎ 摘　　要

Porous graphene aerogel (GA) was prepared by the hydrothermal reduction of graphene oxide (GO). The prepared GA was characterized with the various analytical techniques. Its morphological and electrochemical properties were investigated and compared with those of GO and electrochemically reduced graphene oxide (erGO). Three glassy carbon (GC) electrodes modified with GO, erGO, and GA were employed to study the electrocatalytic oxygen reduction reaction (ORR). The influence of GA porosity on the kinetic parameters of the ORR was also investigated. Whereas two-electron transfer ORR was observed at the erGO- and GO-modified electrodes, the GA-modified electrode exhibited drastically enhanced electrocatalytic ORR activity. The remarkable electrocatalytic activity of GA can be attributed to the unique porous effect of GA. The porous GA offers confined spaces for ORR that would drastically increase the residence time of oxygen and thus enhance the contact frequency for the reduction of oxygen. Additional rotating disk electrode voltammetry corroborates that the porous GA facilitates efficient ORR.