▎ 摘　　要

Although direct methanol fuel cells present a huge potential for application in modern society, the lack of high-efficiency anode catalysts with acceptable cost has largely hindered their large-scale commercialization. Here, we demonstrate a bottom-up approach for the fabrication of ultrafine Pt nanoparticles dispersed on 3D low-defect carbon nanotube/nitrogen-doped graphene hybrid aerogels (Pt/LDCNT-NG) via a convenient and cost-effective self-assembly process. Both experiments and theoretical calculations reveal that the rationally assembled 3D Pt/LDCNT-NG architectures possess a low defect density, optimized electronic structure, and enhanced Pt stability, thus showing high electrocatalytic activity as well as a long lifespan toward the methanol oxidation reaction, which are far superior to those of conventional Pt/carbon black, Pt/acid-treated CNT, Pt/graphene, and Pt/nitrogen-doped graphene catalysts. It is anticipated that the synthetic strategy presented here can be further extended to the construction of various 3D heteroatom-doped low-defect carbonaceous nanomaterials that contain metals or metal oxides, which are conducive to the development of high-performance energy storage and conversion devices.