Isolated Fe atoms dispersed on cellulose-derived nanocarbons as an efficient electrocatalyst for the oxygen reduction...

Cost-effective preparation of efficient electrocatalysts is vitally important for energy storage and conversion. Here, a facile chemical activation strategy using biomass cellulose as the carbon feedstock to fabricate isolated Fe atoms dispersed on a nitrogen doped graphene/nanocarbon hybrid is reported. This new single atom catalyst aFe-NGC worked as an excellent electrocatalyst towards the ORR compared to commercial Pt/C with 30 mV higher positive half-wave potential, larger current density, better stability and stronger methanol-tolerance. The key active sites for enhancing the ORR activity originated from the constructed high loading Fe-N/C configuration coupled with doped nitrogens, as explored by optimizing the activation temperatures and characterized by state-of-the-art techniques including aberration-corrected STEM and synchrotron XANES. This strategy could be developed into a general approach to prepare highly efficient atomic metal electrocatalysts using abundant biomass as a cost-effective carbon source.