Tailored NbO₂ Modified Pt/Graphene as Highly Stable Electrocatalyst Towards Oxygen Reduction Reaction

Abstract

Abstract The stability issues of electrocatalysts caused by the severe corrosion of support materials (commonly carbon materials) were regarded as the main reasons accounting for the failure of proton exchange membrane (PEM) fuel cell during operation. In this paper, a simple one‐pot method was developed to synthesize NbO 2 ‐graphene composite support material, which Pt nanoparticles were then facilely deposited to compose the triple phase boundary (TPB) to provide excellent structure for performance enhancement. The morphology, structure and composition were conducted by scanning electron microscopy (SEM), transmission electron microscope (TEM), X‐ray diffraction (XRD), X‐ray photoelectron spectra (XPS). Meanwhile the electrochemical behavior was estimated by cyclic voltammetry (CV), linear sweep voltammetry (LSV), and accelerated degradation test (ADT). Such Pt‐NbO 2 ‐graphene catalyst exhibits the enhancement of both long‐term stability and oxygen reduction reaction (ORR) activity remarkably. Particularly, the LSV polarization curve of Pt‐NbO 2 ‐graphene catalyst almost has no degradation after ADT for 10,000 cycles. Meanwhile, as a comparison, Pt‐graphene and commercial Pt‐C (20%) catalysts present negative shift of half‐wave potential for 37 mV and 160 mV. Moreover, the half‐wave potential of Pt‐NbO 2 ‐graphene is observed to negatively shift for only 17 mV until performing ADT of 18,000 cycles. This catalyst is a promising candidate for practical fuel cell applications.