Abstract Perovskite oxide has been emerging as one of the efficient heterogeneous catalysts for advanced oxidation of organic contaminants in wastewater because of their structural integrity and compositional tunability. Herein, we report a new perovskite oxide, La1.15MnO3+δ with excess La, for a lowered average oxidation state of Mn cations and abundant oxygen vacancies, which can be active sites for peroxymonosulfate (PMS) activation. The La1.15MnO3+δ did exhibit improving catalytic performance as compared to LaMnO3+δ for the degradation of Rhodamine B by activating PMS. Besides, it also demonstrated high tolerance to variant water environments such as temperature, pH and impurity anions. A major non-radical activation mechanism dominated by 1O2 was further confirmed in La1.15MnO3+δ/PMS system, accompanied by a minor radical pathway. This work provides a new effective strategy to advance catalytic PMS oxidation processes by tailoring the oxidation state of B-site metals and defects of perovskite oxide through manipulating A-site cation stoichiometry.

中文翻译：

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非化学计量钙钛矿通过过量 A 位阳离子增强催化氧化

摘要 钙钛矿氧化物由于其结构完整性和成分可调性，已成为废水中有机污染物高级氧化的有效多相催化剂之一。在此，我们报告了一种新的钙钛矿氧化物 La1.15MnO3+δ 与过量的 La，用于降低 Mn 阳离子的平均氧化态和丰富的氧空位，这些氧空位可以成为过硫酸盐 (PMS) 活化的活性位点。与 LaMnO3+δ 相比，La1.15MnO3+δ 确实表现出改善的催化性能，通过活化 PMS 降解罗丹明 B。此外，它还表现出对温度、pH 值和杂质阴离子等不同水环境的高度耐受性。在 La1.15MnO3+δ/PMS 体系中进一步证实了以 1O2 为主的主要非自由基活化机制，并伴有次要自由基途径。