Catalytic hydrolysis of trifluoromethane over alumina

Catalytic hydrolysis over alumina was carried out at temperatures between 350 degrees C and 520 degrees C and gas hourly space velocity (GHSV) of 6000 h(-1). The effects of water vapor concentration, alumina phase, and Zn promoter as well as the reaction mechanism were investigated in detail. The results show that the presence of small amounts of water vapor (0.8%) significantly improves the activity of -Al2O3, while higher water vapor concentration (>2.8%) does not further enhance the decomposition of CHF3. Compared with -Al2O3 and AlOOH, -Al2O3 is inactive for the targeted reaction although it is stable under conditions studied (with the presence of HF product). Zn is an efficient promoter for the improvement of activity and stability of alumina catalyst. More attention is paid to the reaction and deactivation mechanism. Based on the experimental results and thermodynamic analysis, a reaction mechanism is proposed which explains the effect of water vapor and deactivation of catalyst reasonably.