Highly active and stable RuO/MgF catalysts for efficient HCl oxidation in the fluorochemical industry

The catalytic oxidation of gaseous HCl with a small amount of HF to Cl is important and highly desired for chlorine recycling in the fluorochemical industry. In this work, a series of partly hydroxylated magnesium fluorides were prepared via fluorolytic and solvothermal synthesis methods at different solvothermal reaction times and used as supports to prepare RuO/MgF catalysts via an incipient impregnation method. Both supports and catalysts were extensively characterized with different techniques to gain insight into their physicochemical properties. Furthermore, these prepared RuO/MgF catalysts were evaluated in the oxidation of HCl with a HF concentration of 400 ppm. It is found that at an optimal solvothermal reaction time, the bridging -OH groups can be abundantly formed on MgF, which can significantly enhance the adsorption of the Ru-complex anions via an electrostatic attraction during the impregnation to greatly increase the dispersion of RuO on MgF and affect the chemical environment of RuO, resulting in pronounced catalytic activity and stability. The current study, therefore, provides a strategy to develop an efficient catalyst for the oxidation of HCl contaminated with HF.