Enhanced catalytic elimination of chlorobenzene over Ru/TiO2 modified with SnO2—Synergistic performance of oxidation and acidity

• Published in: Chemical physics Vol. 566; p. 111787
• Main Authors: Liang, Wenjun, Zhu, Yuxue, Ren, Sida, Shi, Xiujuan
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01-02-2023
• Subjects: Acidity; Catalytic oxidation; Chlorobenzene; Chlorobenzene; Catalytic oxidation; Acidity; Ru; Sn
• ISSN: 0301-0104
• DOI: 10.1016/j.chemphys.2022.111787

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•Reducing the content of noble metal, improving the activity at low temperature.•SnO2 promotes crystal phase transition and affected activity.•Ru-Sn/TiO2 had the synergistic effect of oxidation and acidity.•The increase of acidity is conducive to the improvement of HCl selectivity.
The chlorine poisoning of catalyst caused by catalytic oxidation of CVOCs after long-term operation is still the bottleneck of its large-scale industrial application. In this work, Ru-xSn/TiO2 catalysts with oxidation and acid function were prepared by the typical impregnation method, and the catalytic oxidation of chlorobenzene (CB) was also investigated. Meanwhile, the doping of Sn could make the catalyst maintain excellent activity on the basis of reducing the content of noble metals. The optimal catalytic oxidation activity of CB was obtained by doping 10 % Sn on 0.4Ru/TiO2, and the T10 and T90 values were 140 °C and 195 °C, respectively, which were similar to that of 2.0Ru/TiO2. SnO2 improved the concentration of Ru4+ on the surface of the catalyst and formed a solid solution with TiO2 to promote the crystal phase structure of anatase-TiO2 to rutile, resulting in an increase of surface defect sites. The acidity of Ru-Sn/TiO2 catalyst was higher than that of Ru/TiO2 catalyst and the Lewis acid would increase with the formation of SnOTi, while RuO2 was mainly the Brönsted acid center, so it had a suitable B/L ratio. CO2 was almost the only carbon-containing product, the oxidation processproducts were mainly benzoquinone, maleate, acetate, aldehydes and other intermediates. Most chlorine species were removed as HCl and Cl2 under the promotion of Deacon reaction.