Preparation of Iron‐ and Nitrogen‐Codoped Carbon Nanotubes from Waste Plastics Pyrolysis for the Oxygen Reduction Reaction

A novel method to prepare iron and nitrogen co-doped carbon nanotubes (Fe-N-CNT) is proposed, based on catalytic pyrolysis of waste plastics. At first carbon nanotubes are produced from pyrolysis of plastic waste over Fe-Al2O3; then Fe-CNT and melamine are heated together in inert atmosphere. Different co-pyroysis temperatures are tested to optimize the electrocatalyst production. Working at a high doping temperature improved the degree of graphite formation and promoted the conversion of nitrogen to a more stable form. Compared with commercial platinum on carbon, the electrocatalyst obtained from pyrolysis at 850 °C, showed remarkable properties, with onset potential of 0.943 V vs RHE and half-wave potential of 0.811 V vs RHE and even better stability and anti-poisoning. In addition, zinc-air batteries tests were also carried out and the optimized catalyst exhibited high maximum power density.