Mn decorated UIO-66 catalyst for gaseous toluene removal: Synergistic effect of enhanced hydroxyl from H2O2

• Mn/UIO-66 was used in vaporized hydrogen peroxide system for toluene removal. • Toluene removal efficiency of 82% was obtained due to hydroxyl radical oxidation. • Excessive manganese decoration caused Mn/UIO-66 poor surface characteristic. • Toluene decomposed into small organic molecules and finally converted into CO 2 . Gaseous toluene, one of the volatile organic compounds, has aroused wide concerns in China due to its growing emissions and harmfulness. Herein, novel manganese decorated UIO-66 catalysts (Mn/UIO-66) were prepared by hydrothermal synthesis and applied to the vaporized hydrogen peroxide system for toluene removal. TEM, BET, XRD, ICP, and XPS were used to analyze the chemical and physical characteristics of Mn/UIO-66. A toluene removal efficiency of 82% with the 3-Mn/UIO-66 catalyst in the vaporized hydrogen peroxide system could achieved. The effects of different reaction conditions (reaction temperature, hydrogen peroxide concentration, and initial toluene concentration) on toluene removal were determined. The yield of hydroxyl radical in the Mn/UIO-66 catalyst combined with the hydrogen peroxide system was positively correlated with the Mn decorated ratio. Results suggested that the catalytic performance is related not only to the yield of hydroxyl radical but also to the catalyst specific surface. The intermediate products during toluene removal were analyzed by gas chromatography-mass spectrometry (GC–MS), and the possible reaction pathway of toluene removal was proposed.