PtFe/nitrogen-doped graphene for high-performance electrooxidation of formic acid with composition sensitive electrocatalytic activity

Abstract

With the aim to pursue novel high-performance electrocatalysts for fuel cells, a simple synthesis strategy, which consists of hydrothermal reaction followed by solid state reduction by H₂, is developed to prepare a series of Pt_xFe_100−x/N-doped graphene nanocomposites with controllable Pt : Fe compositions. The morphology, microstructure, and composition of the samples are systematically characterized with transmission electron microscopy, scanning electron microscopy, energy dispersive spectroscopy, powder X-ray diffraction, X-ray photoelectron spectroscopy and Raman spectroscopy. The effects of nitrogen doping and alloying with Fe, as well as their synergistic interactions, on the improvement of the catalytic performance are well revealed by using the present samples as catalysts for formic acid electrooxidation. Additionally, the composition sensitive catalytic activity and stability of these catalysts for formic acid electrooxidation are probed and the optimum Pt : Fe ratio is presented. The optimum sample possesses both enhanced electrochemical performance and a reduced dosage of the noble metal, making it a promising candidate for fuel cell applications.