Synergistic dual-pathway activation of peroxymonosulfate via topochemically engineered A-site deficient BaMnO₃...

Peroxymonosulfate (PMS)-based advanced oxidation processes show great potential for wastewater treatment, yet their efficiency and stability are often limited by insufficient catalytic activity and mechanistic constraints. To address this, we developed A-site deficient Ba_1-xMnO₃ perovskites via a topochemical approach for enhanced PMS activation. These engineered defects preferentially expose active (010) facets, promote Mn redox cycling, and modulate electron structure, shifting the degradation mechanism from a radical-dominated process to a synergistic radical/non-radical dual pathway. This results in significantly improved activity and stability, achieving a threefold increase in paracetamol degradation efficiency. Mechanistic studies confirm that radicals ensure fast mineralization while electron transfer prevents surface passivation. The catalyst also demonstrates broad applicability, effectively degrading multiple pharmaceuticals and assisting plastic depolymerization. Furthermore, it outperforms existing Mn-based perovskites in PMS activation under various conditions. This work provides a defect-engineering strategy for designing robust perovskite catalysts in environmental remediation.