Catalytic oxidation of dimethyl phthalate over titania-supported noble metal catalysts

• Published in: Journal of hazardous materials 2021-01, Vol.401, p.123274-123274, Article 123274
• Main Authors: Liang, Yuting, Li, Jiayi, He, Yaoyu, Jiang, Zhi, Shangguan, Wenfeng
• Format: Article
• Language: English
• Subjects: Catalytic oxidation; DMP; Indoor SVOCs; Pd/TiO2
• ISSN: 0304-3894; 1873-3336
• DOI: 10.1016/j.jhazmat.2020.123274

[Display omitted] •An efficient methodology is proposed to investigate catalytic oxidation of SVOCs.•Catalytic oxidation is proved as validated process to remove indoor DMP.•DMP catalytic oxidation activity is correlated with the type of supported metal.•Side chain cleavage and ring broken comprise pathway of DMP catalytic oxidation. Semi-volatile organic compounds (SVOCs) are organic compounds with the boiling point ranging between 240/260 ℃ and 380/400 ℃. Detailed knowledge regarding catalytic removal of SVOCs from indoor environment is very limited as it remains challenge to explore such reaction due to the viscosity nature of target contaminants. Here, we established a facile methodology to explore the heterogeneous catalytic oxidation reaction of dimethyl phthalate (DMP), a model SVOC, over the surface of supported catalyst. DMP was found to be gradually oxidized over the surface of titania supported catalysts including palladium (Pd), platinum and ruthenium with increasing temperature. The cleavage of side chain of DMP occurs at 75 ℃ over the surface of Pd/TiO2, which is significantly lower than that of the other two catalysts. Carbon dioxide was observed as the main product of the catalytic oxidation reaction. However, aromatic products and small molecule products were still observed as side-product in different temperature range. Density functional theory calculations further show that DMP can react with reactive oxygen species to form phthalic acid. While the cleavage of the DMP side chain occurs to form products such as methyl benzoate. This work thus provides basic knowledge about indoor SVOCs catalytic oxidation removal.