Compared with the traditional complex and costly anthraquinone route, electrocatalytic oxygen reduction is a novel, safe, and environmentally friendly strategy for the production of hydrogen peroxide (H2O2). In this paper, we design a hierarchical three-dimensional (3D) porous carbon (PC-O/IT) using a double-template method. The combined action of the two kinds of templates can effectively control the pore structure of the obtained porous carbon, and the hierarchical porous structure shows positive effects on the electrocatalytic oxygen reduction reaction (ORR). Furthermore, oxygen-doped PC-O/IT is synthesized by simply oxidizing PC-O/IT, and the PC-O/IT-400 obtained at 400 degrees C has obvious two-electron transfer (n = 2.82) for the ORR, showing an optimized H2O2 selectivity (59.20%). This work not only provides a novel strategy for the design of electrocatalysts with high catalytic performance in a two-electron oxygen reduction reaction (2e(-) ORR) but also promotes a deeper understanding of the roles of organic and inorganic templates in solvent-free synthesis.