Process and mechanism of PPCPs degradation via high-temperature regulated FeCN composite catalyst-activated peroxymonosulfate

Conventional high-temperature synthesis for peroxymonosulfate (PMS) catalysts is typically confined to the range of 200–900 °C, leaving the properties and mechanisms of catalysts synthesized at ultra-high temperatures (>1000 °C) as an open question. This study systematically investigated preparation temperatures ranging from 800 to 1600 °C by developing a series of Fe-C-N-based catalysts, using the pharmaceutical pollutant esmolol (ES) as a model contaminant to evaluate PMS activation performance. The 1400-FeCN catalyst synthesized at 1400 °C demonstrated optimal performance, achieving 95 % ES degradation within 15 min (pseudo-first-order rate constant: 0.21 min −1 ) while maintaining stable activity across a broad pH range (7.4–9.4). The system exhibited remarkable tolerance to common aqueous anions (Cl − , SO 4 2− , CO 3 2− , ClO 4 − ) and maintained effective degradation performance in real hospital wastewater matrices. Mechanistic studies identified iron(IV)-oxo (Fe IV =O) complexes as the dominant reactive species responsible for contaminant oxidation. This work establishes both fundamental principles and practical methodologies for developing ultra-high-temperature PMS catalysts.