Facile synthesis of uniform AuPd@Pd nanocrystals supported on three-dimensional porous N-doped reduced graphene oxide hydrogels as highly active catalyst for methanol oxidation reaction

Abstract

Porous reduced graphene oxide hydrogels (RGOH), especially as supports for immobilizing metallic nanocrystals have attracted great attention in advanced nanomaterials, which have broad applications in catalysis, sensing and electric/optical devices. Herein, uniform core-shell AuPd@Pd nanocrystals supported on three-dimensional (3D) porous N-doped RGOH (AuPd@Pd NCs/N-RGOH) are facilely prepared by combining hydrothermal treatment with wet-chemical co-reduction. Ethylenediamine (EDA) is used as the nitrogen source and assembly agent for N-RGOH under hydrothermal conditions, and also as the structure-director for AuPd@Pd NCs during the wet-chemical co-reduction process. The nanocomposites display enhanced catalytic activity and stability for methanol oxidation reaction (MOR) in comparison with Pd NPs/N-RGOH and commercial Pd-C catalysts, owing to the unique structure and abundant nitrogen of N-RGOH, along with the synergistic effects between N-RGOH and AuPd@Pd NCs.