Single-atom Fe catalysts anchored on graphitized chitin-derived carbon for improved anti-interference ability of Fenton-like reaction via non-radical pathway.

[Display omitted] The 1O 2 -dominated radical pathway is highly active for the complex aquatic environments, but the 1O 2 generation with high efficiency and selectivity is difficult. Herein, iron single-atom catalysts (SACs) supported on graphitized chitin-derived carbon (Fe 1 /NC-700) are synthesized by ball milling combined with high-temperature pyrolysis method using chitin as a carbon and nitrogen source. Fe 1 /NC-700 exhibits excellent catalytic performance and satisfactory stability in the activation of peroxymonosulfate (PMS) for the degradation of acid orange 7 (AO7), the degradation efficiency is 99.8 % within 5 min, and its apparent rate constant k can reach 0.5695 min−1, which is 3 times higher than that of Fe NPs /NC-700. Free radical scavenging experiments, electron spin resonance, in-situ Raman spectroscopy, and electrochemical analyses demonstrate that the degradation process is a 1O 2 -dominated non-radical pathway with the auxiliary participation of Fe(IV)=O and electron transfer, the 1O 2 selectivity is 96.2 %, while Fe(IV)=O and e– are 3.8 %, causing Fe 1 /NC-700 + PMS system exhibits superior anti-interference ability. The reaction mechanism shows that pyrrolic N is the adsorption sites for pollutants, whilst Fe-N x and graphite N are the activation sites for PMS, meanwhile, the graphite N can facilitate the transfer of electron, resulting in the production of large amounts of 1O 2 for the degradation process. [ABSTRACT FROM AUTHOR]