Transition-metal oxide photocatalysis has attracted increasing attention in environmental remediation and solar energy conversion. Surface lattice oxygen is the key active site on the metal oxide, but its role and activation mechanism in the photocatalytic VOC mineralization are still unclear. In this work, we have demonstrated that Sr₂Sb₂O₇ exhibits an excellent photocatalytic activity and stability compared to TiO₂ (P25) in gaseous toluene mineralization because the lattice oxygen on Sr₂Sb₂O₇ can be activated efficiently. The lattice oxygen of Sr₂Sb₂O₇ promotes the adsorption and activation of O₂ and H₂O molecules and enhances the production of ^•O₂^– and ^•OH radicals, as confirmed by the electron spin resonance and DFT calculations. The in situ diffuse reflectance infrared Fourier transform spectroscopy spectra are applied to dynamically monitor the intermediate activation and selective conversion. Combined with DFT calculation, the role and the mechanism of lattice oxygen in photocatalysis have been revealed. Owing to the promoted surface lattice oxygen, the selectivity for benzoic acid formation is enhanced and final product desorption is promoted, which could largely advance the ring opening and mineralization of toluene. This work reveals the origin of lattice oxygen activation and the role for efficient VOC degradation at the atomic scale.

中文翻译：

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Sr ₂ Sb ₂ O ₇上的表面晶格氧活化增强了甲苯的光催化矿化作用：从反应物活化，中间转化到产物解吸

过渡金属氧化物的光催化在环境修复和太阳能转化中已引起越来越多的关注。表面晶格氧是金属氧化物上的关键活性位，但其在光催化VOC矿化中的作用和活化机理仍不清楚。在这项工作中，我们已经证明，在气态甲苯矿化中，Sr ₂ Sb ₂ O ₇与TiO ₂（P25）相比，具有出色的光催化活性和稳定性，因为Sr ₂ Sb ₂ O ₇上的晶格氧可以被有效地活化。Sr ₂ Sb ₂ O ₇的晶格氧促进的O吸附和活化₂和H ₂水分子和提高生产的^• ö ₂ ^-和^•电子自旋共振和DFT计算证实了OH自由基。将原位漫反射红外傅里叶变换光谱应用于动态监测中间活化和选择性转化。结合DFT计算，揭示了晶格氧在光催化中的作用和机理。由于促进了表面晶格氧的存在，苯甲酸形成的选择性得到了提高，最终产物的解吸得到了促进，这可以大大促进甲苯的开环和矿化。这项工作揭示了晶格氧活化的起源以及在原子尺度上有效VOC降解的作用。