LAUSR

Carbon-based electrocatalysts with atomically dispersed Fe-N-C displayed promising performance for oxygen reduction reaction (ORR) amongst non-precious electrocatalysts. Nonetheless, how to increase the number and utilization of Fe-N-C active sites are challenging. Designing morphologies and adjusting the pore structure of carbon-based electrocatalysts would boost the mass transfer, enhance the utilization of the active sites, and increase the overall ORR performance. In this work, a concave N-doped carbon cubes structure adorned with highly external Fe-N x is designed and produced by the space-confined induced strategy. The optimal electrocatalyst reveals excellent ORR activity in both alkaline and acidic electrolytes, with half-wave potentials of 0.86 V and 0.75 V, respectively. The superior performance arises from its unique concave structure, possessing more accessible active sites with improved intrinsic activity, which holds promising potential for preparing advanced ORR electrocatalysts.