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Catalytic oxidation of toluene over noble metal catalysts is a representative reaction for elimination of volatile organic compounds (VOCs). However, to fully understand the activation of molecular oxygen and the role of active oxygen species generated in this reaction is still a challenging target. Herein, MgO nanosheets and single-atom Pt loaded MgO (Pt SA/MgO) nanosheets were synthesized and used as catalysts in toluene oxidation. The activation process of molecular oxygen and oxidation performance on the two catalysts were contrastively investigated. The Pt SA/MgO exhibited significantly enhanced catalytic activity compared to MgO. The oxygen vacancies can be easily generated on the Pt SA/MgO surface, which facilitate the activation of molecular oxygen and the formation of active oxygen species. Based on the experimental data and theoretical calculations, an active oxygen species promoted oxidation mechanism for toluene was proposed. In the presence of H2O, the molecular oxygen is more favorable to be dissociated to generate OH on the oxygen vacancies of the Pt SA/MgO surface, which is the dominant active oxygen species. We anticipate that this work may shed light on further investigation of the oxidation mechanism of toluene and other VOCs over noble metal catalysts.


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Formation of active oxygen species on single-atom Pt catalyst and promoted catalytic oxidation of toluene

Show Author's information Shunzheng Zhao1,2Yanfeng Wen1Xijun Liu3( )Xianyun Pen3Fang Lü3Fengyu Gao1Xizhou Xie1Chengcheng Du1Honghong Yi1,2( )Dongjuan Kang1( ) Xiaolong Tang1,2( )
Department of Environmental Engineering, University of Science and Technology Beijing, Beijing 100083, China
Beijing Key Laboratory of Resource-oriented Treatment of Industrial Pollutants, Beijing 100083, China
Center for Electron Microscopy and Tianjin Key Lab of Advanced Functional Porous Materials, Institute for New Energy Materials & Low-Carbon Technologies, School of Materials Science and Engineering, Tianjin University of Technology, Tianjin 300384, China

Abstract

Catalytic oxidation of toluene over noble metal catalysts is a representative reaction for elimination of volatile organic compounds (VOCs). However, to fully understand the activation of molecular oxygen and the role of active oxygen species generated in this reaction is still a challenging target. Herein, MgO nanosheets and single-atom Pt loaded MgO (Pt SA/MgO) nanosheets were synthesized and used as catalysts in toluene oxidation. The activation process of molecular oxygen and oxidation performance on the two catalysts were contrastively investigated. The Pt SA/MgO exhibited significantly enhanced catalytic activity compared to MgO. The oxygen vacancies can be easily generated on the Pt SA/MgO surface, which facilitate the activation of molecular oxygen and the formation of active oxygen species. Based on the experimental data and theoretical calculations, an active oxygen species promoted oxidation mechanism for toluene was proposed. In the presence of H2O, the molecular oxygen is more favorable to be dissociated to generate OH on the oxygen vacancies of the Pt SA/MgO surface, which is the dominant active oxygen species. We anticipate that this work may shed light on further investigation of the oxidation mechanism of toluene and other VOCs over noble metal catalysts.

Keywords: oxygen vacancies, single-atom Pt, activation of molecular oxygen, active oxygen species, oxidation of toluene

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Publication history
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Acknowledgements

Publication history

Received: 06 January 2020
Revised: 23 February 2020
Accepted: 21 March 2020
Published: 21 April 2020
Issue date: June 2020

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© Tsinghua University Press and Springer-Verlag GmbH Germany, part of Springer Nature 2020

Acknowledgements

This work was financially supported by the National Natural Science Foundation of China (Nos. 51808037, 21601136 and 21876010), the Science & Technology Development Fund of Tianjin Education Commission for Higher Education (No. 2018KJ126), and the Fundamental Research Funds for the Central Universities (No. FRF-TP-16-060A1). The authors wish to thank facility support of the 1W1B and 4B9A beamline of Beijing Synchrotron Radiation Facility (BSRF).

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