Precisely tailoring the A-site of perovskite oxides for boosting peroxymonosulfate activation: Catalytic performance and decomposition mechanism

• The LaCoO 3 /La(OH) 3 was prepared via alkoxide hydrolysis to reconstruct in situ the A-site of LaCoO 3 . • The inactive La-sites of LaCoO 3 were converted into active centers. • The LaCoO 3 /La(OH) 3 membrane reactor exhibited a k obs value of 441.34 min −1 and good stability. Advanced oxidation processes have emerged as a powerful class of technologies to activate peroxymonosulfate (PMS) for the degradation of refractory organic pollutants. A challenge is the mass transfer efficiency from the catalyst to PMS for reactive oxygen species production. Considering that the A-site of perovskite oxides is not directly involved in PMS activation, a novel strategy of alkoxide hydrolysis has been designed to modify in situ the A-site of LaCoO 3 for the synthesis of LaCoO 3 /La(OH) 3 (LC24), where the inactive La-sites of perovskite oxides are converted into active centers. Systemic characterizations and density functional theory calculations reveal that the La and Co sites collectively function as the active site of LC24, and the formation of Co (3d)-O (2p)-La (4f) bridge bond enhances electron conductivity. PMS adsorbed at the LC24 heterogeneous interface is mainly activated into SO 4 − and 1 O 2 . The LC24/PMS system exhibits high catalytic activity with reaction rate constant (k obs ) of 0.702 min −1 and 98.71 % removal of enrofloxacin (ENR) within 8 min. A miniature catalytic membrane reactor of LC24 has been built, demonstrating excellent ENR degradation performance (k obs = 441.34 min −1 ) and good stability. The study provides a new design guideline for active center modulation of catalytic materials for environmental remediation.