Metal-organic frameworks derived cobalt encapsulated in porous nitrogen-doped carbon nanostructure towards highly efficient and durable oxygen reduction reaction electrocatalysis

Abstract

In this study, metal-organic frameworks (MOFs) derived cobalt encapsulated in porous nitrogen-doped carbon (Co/N–C) nanocomposite electrocatalyst is developed towards the highly efficient and durable oxygen reduction reaction (ORR) via pyrolysis of core-shell MOFs precursor. Electrochemical characterization results indicate that the as-prepared Co/N–C nanocomposite shows superior ORR selectivity through a four-electron pathway and extraordinary long-term stability. The uniform nitrogen dopants on the surface of the polyhedron are determined and deconvoluted by the X-ray photoelectron spectroscopy (XPS). We contribute this superior catalytic activity to the characteristic attributes of Co/N–C nanocomposite, which could be stemmed from its exquisite catalyst design: (i) the existence of Co/N-doped carbon nanotubes nanostructure on the catalyst surface and (ii) the proper nitrogen content on the N-doped carbon (N–C) layer. Moreover, Co/N–C nanocomposite presents favorable long-term catalytic stability for 60 h, owning to the protective effect of the porous N–C layer. The present work demonstrates that the MOFs-derived nanomaterial can be transformed into high-value functional transition metal/N-doped carbon nanocomposite electrocatalysts. From both the stability and activity prospects, our work opens a new avenue to strategically design highly active and stable-oriented electrocatalysts.