Hollow porous Co-N dual-doped oxygen reduction reaction catalyst prepared using spherical nanosheet structure template

Abstract

In order to solve the problems of poor catalytic activity of non-precious metal catalysts and low utilization of active sites in anion exchange membrane fuel cells. In this paper, catalyst precursors of Co²⁺ chelated dopamine-coated melamine cyanuric acid templates were synthesized by the template method at room temperature. Three-dimensional nanosheet crosslinked hollow Co, N dual-doped carbon nanostructures (CoO_x@NHCS) electrocatalysts were prepared by rational carbonization. The CoO_x@NHCS with highly open porous structure can effectively promote the transport of gases and products. The catalyst exhibited a half-wave potential of 0.866 V and a limiting current density of 5.25 mA cm⁻² in alkaline media, as well as a kinetic current density 1.4 times higher than that of commercial Pt/C at 0.85 V. CoO_x@NHCS was used as a cathode catalyst for anion exchange membrane fuel cells with a loading mass of 2.5 mg cm⁻², and the maximum power density of anion exchange membrane fuel cells reached 234 mW cm⁻². In addition, the catalyst exhibited remarkable methanol tolerance and good stability under operating conditions. A new idea is provided for the preparation of heteroatom-doped carbon catalysts with a three-dimensional porous structure for application in anion-exchange membrane fuel cells.