Fe7C3 nanoparticles with in situ grown CNT on nitrogen doped hollow carbon cube with greatly enhanced conductivity and ORR performance for alkaline fuel cell

Reasonable design of the porous metal-organic frameworks (MOFs) to convert a burgeoning carbonbased catalysts with high oxygen reduction reaction (ORR) activity are still challenging in energy conversion, storage and transport. Herein, Fe7C3-doped in-situ grown carbon nanotubes and N-doped hollow carbon (Fe-x-CNT@NHC) are prepared by using a simple and robust preparation method, which is used cubic ZIF-8-derived zinc oxide cubes as a template for secondary MOFs re-growth followed by the final carbonization. In the 0.1 M KOH, the as-pyrolyzed Fe-0.1-CNT@NHC electrocatalyst displays the value of half-wave potential is 0.92 V and the value of diffusion-limited current density is 6.08 mA cm(-2), respectively, which are close to the corresponding electrochemical values of the standard commercial Pt/C (0.89 V and 5.89 mA cm(-2)). Meanwhile, the material has passed relevant tests on its long-term stability and methanol tolerance in alkaline media, showing that it has excellent ORR activity and efficient stability under electrocatalysis. Furthermore, the Fe-0.1-CNT@NHC materials catalyze a Zn-air battery that delivers a performed peak power density of 105.9 mW cm(-2). The impressive catalytic activity of Fe-0.1-CNT@NHC stems from the effective synergy between efficient Fe and N co-doping, large specific surface area, and high electrical conductivity. This preparation route for carbon nanomaterials will provide a new synthetic strategy to synthesize high-performance non-noble metal carbon-based ORR catalysts for practical energy-related applications. (C) 2020 Elsevier Ltd. All rights reserved.

Automated summary

A new preparation method was used to prepare Fe7C3-doped carbon nanotubes and N-doped hollow carbon, demonstrating excellent ORR activity and stability. The material showed comparable electrochemical performance to commercial Pt/C in alkaline media, indicating great potential for practical applications.