High-loading of well dispersed single-atom catalysts derived from Fe-rich marine algae for boosting Fenton-like reaction: Role identification of iron center and catalytic mechanisms

Developing single-atom catalysts (SACs) with superior Fenton-like performance and low-cost via green synthesis strategy is an urgent problem. It was for the first time to prepare the iron single-atom catalyst (Fe-SAC) with highly atomically-dispersion from natural Fe-rich marine algae (Enteromorpha) with iron amount over 1.5 wt%. Iron screening test indicated that the activation performance of Enteromorpha-derived Fe-SACs catalyst was mainly based on Fe-N4-C sites, and the roles of radicals accompanying with Fe(IV) and 1O2 oxidation showed very small contributions. In contrast, the degradation of organic was dominated by the electron-transfer process (ETP), and the ETP mechanism was greatly enhanced by the iron centers in the Enteromorpha-derived Fe-SACs, which could help extract more electrons from the organics to the Fe-N4-C/PMS complex, thus facilitating the ETP in catalytic system. In addition, the commercial ceramic membrane (CM) coated with Enteromorpha-derived Fe-SACs catalyst showed superior catalytic activtiy with a stable water flux.

Automated summary

Developing effective and cost-efficient single-atom catalysts (SACs) with Fenton-like performance through green synthesis is a pressing issue. In this study, highly atomically-dispersed iron single-atom catalysts (Fe-SACs) were successfully prepared from natural iron-rich marine algae (Enteromorpha) with iron content exceeding 1.5 wt%. The Fe-SACs derived from Enteromorpha exhibited superior activation performance based on Fe-N4-C sites, while the contribution of radicals and oxidation processes were minimal. Additionally, the Fe-SACs greatly enhanced the electron-transfer process (ETP) mechanism, enabling efficient extraction of electrons from organics and promoting catalytic activity.