New insights into Sr-O bonds enhances Co/Fe catalytic activity in SrCoFe perovskite for boosted peroxymonosulfate activation

It is of significant to explore activation mechanism of peroxymonosulfate (PMS) for development of more active and robust metal oxide catalyst. Here, we discover a key role of Sr-O bond in boosting the catalytic activity of SrCo0.81Fe0.19O2.78 perovskite. In this catalytic system, oxygen vacancy, Fe4+/Fe3+, and Co3+/Co2+ redox cycles synergistically enhanced catalytic activity of SrCo0.81Fe0.19O2.78 for antibiotic degradation with 100 % Florfenicol (FF) removal in 27 min. Moreover, this catalyst presented excellent stability although oxygen vacancy had a decrease after reuse. The influential factors including coexisting anions on FF degradation were systematically studied. Comparative experiments and theoretical calculation indicate Sr-O ionic bond provides electrons for CoO and Fe-O covalent bonds to accelerate Fe4+/Fe3+, and Co3+/Co2+ redox cycles for PMS activation. Finally, the FF degradation pathway over SrCoFe perovskite/PMS system was identified by LC-MS/MS.

Automated summary

The study identified the crucial role of Sr-O bond in boosting the catalytic activity of SrCo0.81Fe0.19O2.78 perovskite, where oxygen vacancy, Fe4+/Fe3+, and Co3+/Co2+ redox cycles synergistically enhanced catalytic activity. The Sr-O ionic bond was found to provide electrons for CoO and Fe-O covalent bonds, accelerating Fe4+/Fe3+ and Co3+/Co2+ redox cycles for PMS activation, leading to efficient removal of antibiotics.