Engineering Brønsted acid sites for enhanced nonradical pathways in antibiotic contaminant degradation

Peroxymonosulfate (PMS)-mediated advanced oxidation processes (AOPs) via nonradical pathways offer high selectivity and efficiency for pollutant degradation. However, achieving precise control over these pathways through catalyst design remains a significant challenge. This study focuses on Mn x Cu 0.4 Ni-layered double hydroxides (Mn x Cu 0.4 Ni-LDH) as catalysts optimized for enhancing PMS activation through a singlet oxygen ( 1 O 2 )-mediated pathway. Structural analysis reveals that Mn x Cu 0.4 Ni-LDH, featuring a Cu-Ov-Mn(IV) configuration, create Brønsted acid sites essential for catalysis. Compared to Cu 0.4 Ni-LDH, Mn x Cu 0.4 Ni-LDH demonstrates higher stability and efficiency in PMS activation, producing significant 1 O 2 (11.22 μM) and achieving superior degradation rates (0.29 min −1 for levofloxacin). Density functional theory (DFT) simulations suggest that Brønsted acid sites, synergistic Cu atoms and Mn atoms interactions, and oxygen vacancies (Ov) collectively enhance PMS activation by stabilizing active sites and facilitating electron transfer. These advancements improve catalyst performance, highlighting a promising strategy for pollutant-specific nonradical oxidation.