Catalytic hydrolysis of CHClF₂ and CCl₂F₂ over solid base MgO/ZrO₂ catalyst

We prepared the solid base MgO/ZrO₂ catalyst by the coprecipitation method and the impregnation method. The catalyst was revealed by XRD, SEM, N₂ adsorption-desorption. The catalyst calcination temperature, catalytic hydrolysis temperature and preparation technique on the hydrolysis rates of HCFC-22 and CFC-12 were investigated. The results showed that the MgO/ZrO₂ catalyst prepared by coprecipitation method and impregnation method had better catalytic hydrolysis effect on HCFC-22 than CFC-12, when the calcination temperature was 700 ℃ and the catalytic hydrolysis temperature was 400 ℃. The hydrolysis rate of HCFC-22 and CFC-12 were the highest, reaching 99.64% and 98.03% respectively. X-ray diffraction (XRD) and N₂ adsorption-desorption test results showed that the MgO/ZrO₂ catalyst had a mesoporous structure. The SEM test results stated that the MgO/ZrO₂ catalyst was calcined at 700 ℃ without sintering, it showed that the active components could fully contact with the gas HCFC-22 and CFC-12, which was beneficial to the degradation of HCFC-22 and CFC-12 during the catalytic reaction process. The EDS analysis results indicated the degradation products were HF, HCl and CO₂.