Singlet Oxygen Induced Site‐Specific Etching Boosts Nitrogen‐Carbon Sites for High‐Efficiency Oxygen Reduction

Targeted construction of carbon defects near the N dopants is an intriguing but challenging way to boost the electrocatalytic activity of N‐doped carbon toward oxygen reduction reaction (ORR). Here, we report a novel site‐specific etching strategy that features targeted anchoring of singlet oxygen (1O2) on the N‐adjacent atoms to directionally construct topological carbon defects neighboring the N dopants in N‐doped carbon (1O2−N/C). This 1O2−N/C exhibits the highest ORR half‐wave potential of 0.915 VRHE among all the reported metal‐free carbon catalysts. Pyridinic‐N bonded with a carbon pentagon of the neighboring topological carbon defects is identified as the primary active configuration, rendering enhanced adsorption of O2, optimized adsorption energy of the ORR intermediates, and a significantly decreased total energy barrier for ORR. This 1O2‐induced site‐specific etching strategy is also applicable to different precursors, showing a tremendous potential for targeted construction of high‐efficiency active sites in carbon‐based materials. Singlet oxygen (1O2) specifically targets the N‐adjacent atoms and acts as an etchant to realize site‐specific etching of topological carbon defects neighboring the N‐dopants, leading to a boosted intrinsic catalytic activity of the N−C sites in the resultant N‐doped carbon (1O2−N/C). The 1O2−N/C exhibits the highest half‐wave potential of 0.915 VRHE toward oxygen reduction reaction among all the metal‐free carbon catalysts reported to date.