Worm-like Pt nanoparticles anchored on graphene with S, N co-doping and Fe_3O_4 functionalization for boosting the electrooxidation of methanol

摘要

Making use of synergy and introducing defects can effectively regulate the electronic structure of carbon nanomaterials, which is of great importance for achieving desired electrochemical performance. Herein, we report a facile protocol for preparing S, N-doped graphene with simultaneous ferroferric oxide functionalization (Fe3O4-SNG), which is then used as support to anchor Pt nanoparticles for catalyzing the anodic reaction of direct methanol fuel cells (DMFCs), the promising portable power sources that have small environmental footprint, compact system design, and higher volumetric energy density compared with existing technologies. The functionalization by Fe3O4 as well as S and N doping increases the defect level in graphene, and also affect the subsequent growth of Pt particles, leading to formation of Pt nanoparticles with worm-like morphology on the surface of Fe3O4-SNG support (Pt/Fe3O4-SNC). The electrochemical evaluations show that the worm-like Pt nanoparticles anchored on Fe3O4-SNG have larger electrochemically active surface areas and enhanced specific activities for methanol oxidation reaction (MOR) due to their strong electronic interaction with the supports, which also promotes the oxidative removal of the intermediate poisoning products formed during methanol electrooxidation, thereby improving the long-term stability of the Pt catalyst. (C) 2020 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.