Nitrogen\nand Fluorine-Codoped Porous Carbons as Efficient Metal-Free Electrocatalysts\nfor Oxygen Reduction Reaction in Fuel Cells

Abstract

The\nsevere dependence of oxygen reduction reaction (ORR) in fuel cells\non platinum (Pt)-based catalysts greatly limits the process of their\ncommercialization. Therefore, developing cost-reasonable non-precious-metal\ncatalysts to replace Pt-based catalysts for ORR is an urgent task.\nHere, we use the composite of inexpensive polyaniline and superfine\npolytetrafluoroethylene powder as precursor to synthesize a metal-free\nN,F-codoped porous carbon catalyst (N,F-Carbon). Results indicate\nthat the N,F-Carbon catalyst obtained at the optimized temperature\n1000 °C exhibits almost the same onset (0.97 V vs RHE) and half-wave\npotential (0.84 V vs RHE) and better durability and higher crossover\nresistance in alkaline medium compared to commercial 20% Pt/C, which\nis attributed to the good dispersion of fluorine and nitrogen atoms\nin the carbon matrix, high specific surface area, and the synergistic\neffects of fluorine and nitrogen on the polarization of adjacent carbon\natoms. This work provides a new strategy for in situ synthesis of\nN,F-codoped porous carbon as highly efficient metal-free electrocatalyst\nfor ORR in fuel cells.