Atomically Dispersed Fe/N-Doped Hierarchical Carbon Architectures Derived from a Metal-Organic Framework Composite for Extremely Efficient Electrocatalysis

Hierarchical graphitic porous carbon architectures with atomically dispersed Fe and N doping have been fabricated from a metal-organic framework (MOF) composite by using a facile strategy, which show high specific surface areas, hierarchical pore structures with macro/meso/micro multimodal pore size distributions, abundant surface functionality with single-atom dispersed N and Fe doping, and improved hydrophilicity. Detailed analyses unambiguously disclosed the main active sites of doped N atoms and FeN_x species in the catalyst. The resultant catalyst affords high catalytic performance for oxygen reduction, outperforming the benchmark Pt catalyst and many state-of-the-art noble-metal-free catalysts in alkaline media, particularly in terms of the onset and half-wave potentials and durability. Such catalytic performance demonstrates the significant advantages of the unique hierarchical porous structure with efficient atomic doping, which provides a high density of accessible active sites for much improved mass and charge transports.