Highly conductive nitrogen-doped carbon/3D graphene composite loaded with Pt for methanol oxidation

Conventional anode Pt electrocatalysts for direct methanol fuel cells (DMFCs) face challenges including the tendency of Pt nanoparticles to migrate and detach, and so on. In this paper, Pt/Co/N-PC/3DG were successfully prepared by loading Pt nanoparticles onto a Co/N-PC/3DG three-dimensional network structure derived from ZIF-67/3D graphene oxide (3DGO), which was obtained by in-situ growth. The structure-performance correlation of the composite carbon support Co/N-PC/3DG and its Pt-loaded counterpart (Pt/Co/N-PC/3DG) for methanol electrooxidation was systematically investigated. Pt/Co/N-PC/3DG-800 demonstrated outstanding catalytic capacity, exhibiting a maximum current density of 553 mA·mg⁻¹_Pt, which was 2-fold the performance observed in commercial Pt/C (277 mA·mg⁻¹_Pt). After 7200 s of chronoamperometric evaluation, the catalyst still retained a current density of 38.4 mA·mg⁻¹_Pt, achieving an 11-fold enhancement over Pt/C (3.4 mA·mg⁻¹_Pt). The enhanced performance stemmed from its architecturally optimized 3D conductive framework, where the hierarchical porosity and interconnected carbon networks synergistically accelerated ion diffusion kinetics and electron transport efficiency. Additionally, coupled with its high nitrogen-doping content and expanded specific surface area, this architecture ensured uniform Pt nanoparticle dispersion and robust anchoring, maximizing its catalytic efficiency.