▎ 摘　　要

Developing highly efficient electro-catalysts for oxygen reduction reaction (ORR) by an economic and green manner is vital for the practical application of fuel cells and metal-air batteries. Herein, inspired by the manufacturing process of sponge tofu (Chinese Food), we develop a sponge tofu-like graphene-carbon hybrid supporting Pt-Co nanoparticles catalyst (denoted as Pt-Co/CB + RGO-3D) by a cheap and environment-friendly freeze-drying technology using ice as the template. The electrochemical tests show that Pt-Co/ CB + RGO-3D exhibits approximately 16-fold higher ORR activity and better stability compared with Pt/C. Its excellent performance could be attributed to the high mass transfer efficiency and enhanced electron transfer capacity, which roots in its unique structure. Furthermore, the Pt-Co/CB + RGO-3D-based Zn-air battery exhibits superior performance, corroborating its commercial application potential. This work not only provides a prospective method to fabricate catalysts with porous structure but also offers an effective strategy to design highly efficient electrocatalysts with special structure. (c) 2021 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.