Manganese/Cobalt Bimetal Nanoparticles Encapsulated\nin Nitrogen-Rich Graphene Sheets for Efficient Oxygen Reduction Reaction\nElectrocatalysis

Abstract

It is of vital importance\nto search for a nonprecious metal based\nsustainable and efficient oxygen reduction reaction (ORR) electrocatalyst\nfor the next generation of energy conversion and storage technology.\nWe herein report a hybrid bimetal material composed of MnO/Co nanoparticles\nencapsulated in nitrogen-rich graphene nanosheets (MnO/Co–N–G)\nas a high performance ORR catalyst in alkaline electrolyte. The MnO/Co–N–G\ncatalyst is derived from Mn²⁺, Co²⁺ incorporated\npolydopamine (PDA) coated graphene oxide (GO) sheets via a carbonization\nprocess. The morphology, structure, and composition properties of\nas-prepared MnO/Co–N–G catalyst are systematically investigated.\nElectrochemical measurements show that the MnO/Co–N–G\ncatalyst exhibits excellent ORR activity superior to commercial Pt/C,\nfeaturing higher limiting current density, better methanol resistance,\nand excellent long-term durability in alkaline solution. The bimetal\nnanoparticles are believed to be responsible for the impressive ORR\nactivity of the catalyst.