The preparation of bifunctional Co-N co-doped carbon with bamboo-like hollow tubular as an efficient electrocatalyst for oxygen reduction and methanol oxidation reaction

Abstract

• Bamboo-like hollow tubular Co-N-C was prepared by direct pyrolysis method. • The Co-N-C catalyst exhibits a high specific surface area. • The Pt@Co-N-C has a high electrochemical surface area. • The Co-N-C and Pt@Co-N-C exhibit excellent ORR and MOR activity and stability. Catalysts with distinguished properties and stability are very important for the oxygen reduction reaction (ORR) and methanol oxidation reaction (MOR) of fuel cells. Herein, we describe a convenient and efficient preparation means to synthesize a bamboo-like hollow tubulous structure Co-N co-doped carbon material (Co-N-C) via a late-model of Co-Imace coordinated compound as the precursor by direct pyrolysis. Additionally, Pt nanoparticles supported by Co-N-C catalysts (Pt@Co-N-C) were prepared using the ethylene glycol reduction procedure. The obtained catalyst exhibited an excellent electro-catalytic property for ORR in alkaline media, which possessed a more positive half-wave potential (0.868V) than commercial Pt/C (0.852V). Moreover, the Co-N-C maintained preeminent long-term stability (91.6 %) after the 21000s and also owned a stronger methanol resistance than Pt/C. The obtained Pt@Co-N-C electrocatalyst exhibited higher MOR activity (96.3 mA cm -2 ), which is 1.6 times greater than that of Pt/C, benefiting from the high electrochemical surface area of Pt@Co-N-C (68 m 2 g -1 ). Furthermore, the Pt@Co-N-C exhibited lower onset potentials, higher I f /I b ratios, and well long-term stability than Pt/C.