Electrochemically reduced graphene-oxide supported bimetallic nanoparticles highly efficient for oxygen reduction reaction with excellent methanol tolerance

Highlights: • Electrochemically reduced GO-supported Pd-Mn₂O₃ (ErGO/Pd-Mn₂O₃) catalyst is synthesized. • The ErGO/Pd-Mn₂O₃ display excellent electrocatalytic activity towards ORR in alkaline media. • The ErGO/Pd-Mn₂O₃ is proceeded by four-electron transfer pathway with little yield of HO₂⁻. • It also shows better durability and excellent methanol tolerance. We report a simple and facile method for the fabrication of bimetallic nanoparticles on electrochemically reduced graphene oxide (ErGO) for electrocatalytic oxygen reduction reaction (ORR) in alkaline media. First, reduced graphene oxide supported palladium and manganese oxide nanoparticle (rGO/Pd-Mn₂O₃) catalyst was synthesized via a simple chemical method at room temperature; then, it was electrochemically reduced for oxidation reduction reaction (ORR) in alkaline media. The chemical composition and morphological properties of ErGO/Pd-Mn₂O₃ was characterized by X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM) and energy-dispersive X-ray spectroscopy (EDS). The TEM images reveals that, nano-sized Pd and Mn₂O₃ particles were disperse on the ErGO sheet without aggregation. The as-prepared ErGO/Pd-Mn₂O₃ was employed for ORR in alkaline media which shows higher ORR activity with more positive onset and half-wave potential, respectively. Remarkably, ErGO/Pd-Mn₂O₃ reduced oxygen via four-electron transfer pathway with negligible amount of intermediate peroxide species (HO₂⁻). Furthermore, the higher stability and excellent methanol tolerance of the ErGO/Pd-Mn₂O₃ compared to commercial Pt/C (20 wt%) catalyst, indicating its suitability for fuel cells.