A facile complex-sequestered strategy has been proposed to fabricate a cost-effective oxygen reduction reaction (ORR) catalyst with Fe single-atom dispersed on nitrogen-doped porous carbon (Fe SA/NPCs). The key step for such an approach is the pyrolysis of an iron-agar complex, in which the “complex-sequestration” effect between hydrated iron(III) and agarose functions to prevent the agglomeration of single Fe atoms. the Fe SA/NPCs catalyst exhibits excellent ORR activities with half-wave potentials comparable to those of commercial Pt/C in media of a broad pH-range, which are superior to those of most reported non-precious-metal ORR electrocatalysts. Moreover, the Fe SA/NPCs catalyst has also demonstrated outstanding durability and methanol tolerance. Density functional theory calculations reveal that the improved electron transfer from single Fe atom onto adsorbed *OH species in the rate-determining step could be the major reason for the exceptional ORR performance of Fe SA/NPCs in both acidic and alkaline media.

已经提出了一种简便的络合物螯合策略来制备具有成本效益的氧还原反应（ORR）催化剂，该催化剂具有分散在氮掺杂多孔碳（Fe SA / NPC）上的Fe单原子。这种方法的关键步骤是铁-琼脂复合物的热解，其中水合铁（III）和琼脂糖之间的“复合螯合”效应起到防止单个Fe原子团聚的作用。Fe SA / NPCs催化剂在宽pH范围的介质中表现出优异的ORR活性，其半波电势与市售Pt / C相当，优于大多数报道的非贵金属ORR电催化剂。此外，Fe SA / NPCs催化剂还具有出色的耐久性和甲醇耐受性。