Catalytic decomposition of CCl2F2 in the presence of water vapor and air was investigated over mesoporous titanium and aluminum phosphates. They are much more active than the ordinary titanium and aluminum phosphates. Comparison between two mesoporous catalysts shows that mesoporous aluminum phosphate is slightly more active than mesoporous titanium phosphate, but the latter catalyst exhibits higher stability than the former one during the reaction. The results based on NH3-TPD and IR show that the activity of the catalysts is correlated with their surface acidity and hydroxyl groups. (c) 2005 Elsevier B.V. All rights reserved.