Synthesis of Ru-Based Catalysts for Complete Oxidation of Volatile Organic Compounds

In this work, low-temperature catalytic oxidation of volatile organic compounds (VOCs) over Ru-based catalysts was presented. The catalysts were prepared using the wet impregnation method, and characterized by ICP, BET, XRD, TEM, and XPS. The catalytic studies demonstrated that P25 supported catalyst contributed the highest activity. Accordingly, Ru/TiO₂(P25) was particularly studied.

Based on the characterizations, we found that ruthenium species exists as ruthenium oxides, which are often hard to observe in TEM micrographs due to their low contrast. Hence, TEM, HR-TEM, and HAADF-STEM charcterizations were conducted. It can be concluded that ruthenium species tend to be distributed on the rutile-TiO2 of P25 due to their similar crystal lattice properties, leading to an inhomogeneous distribution. The catalyst was employed in complete oxidation of different VOCs, including benzene, chlorobenzene, trichloroethene, and methyl bromide. Noteworthy, for chlorinated VOCs, Ru-based catalyst showed apparently better catalytic performance than catalysts, such as Pd or Pt. Additionally, the thermal stability test, anti-moisture test, and byproducts analysis were also conducted, revealing that Ru/TiO₂ is promising for VOCs purifications in industrial plants.