High-Temperature Catalytic Oxidation of 1,2-Dichlorethane: An Alternative Applicable Method for Safe Elimination of CVOCs

Abstract

The application of catalytic removal of chlorinated volatile organic compounds (CVOCs) is restricted by the problems of catalyst deactivation and toxic byproducts. In order to alleviate these problems, the effects of high reaction temperature on the catalytic oxidation of CVOCs are explored by employing thermostable catalysts. Transition metal (Mn, Cu, and Fe)-substituted thermostable hexaaluminate catalysts are prepared and used in the catalytic oxidation of 1,2-dichloroethane (DCE). Mn-substitution and Ru-loading could induce rich active oxygen species and promote reducibility, oxygen mobility, and surface acidity, leading to the improved reaction performance consequently. The inhibition effect on generating chlorinated byproducts by elevating the reaction temperature and the influence of rising temperature on the reaction process are investigated. Catalytic oxidation of DCE over LaMn3 or Ru/LaMn3 at the high-temperature region (over 500 °C) could convert the pollutant into small inorganic molecules (CO2, H2O, HCl, etc.) with scarce chlorinated byproducts. Meanwhile, Ru/LaMn3 presents an excellent structural stability and steady reaction activity at 650 °C. Additionally, DCE oxidation occurs via the pathway of enolic species, vinyl chloride–acetaldehyde–acetate species over LaMn3 and Ru/LaMn3. These results suggest that the high-temperature catalytic oxidation of CVOCs might be a practicable method for safe elimination of CVOCs.