The Hydrolyzation and Hydrolysis Rates of Chlorodifluoromethane during Catalytic Hydrolysis over Solid Acid (Base) MoO₃(MgO)/ZrO₂ Catalyst

Abstract

Chlorodifluoromethane (HCFC-22) is one of the air pollutants that destroy the ozone layer and warm the earth. In order to degrade HCFC-22, the catalytic hydrolysis method is currently the most effective environmental technology. Herein, we prepare solid acid MoO3/ZrO2 and solid base MgO/ZrO2 catalysts for the degradation of HCFC-22, with a particular focus on revealing the effects of the catalyst preparation methods, calcination temperatures, and hydrolysis temperatures on the hydrolyzation and hydrolysis rates of HCFC-22. The catalysts are characterized by XRD, N2 isothermal adsorption–desorption, and NH3-TPD. The results show that the solid acid (base) MoO3(MgO)/ZrO2 catalysts have strong catalytic activity for the degradation of HCFC-22, while the catalytic activity of the solid acid MoZr is better than that of the solid base MgZr catalyst and the hydrolysis rate can reach more than 90%. The water vapor generates B-acid centers on the MoO3(MgO)/ZrO2 framework and promotes the hydrolysis of HCFC-22 to HF and HCl.

Keywords

• chlorodifluoromethane
• catalysis
• hydrolysis
• calcination temperature
• hydrolysis rate