An environmentally friendly solid acid catalyst, Ce(SO4)(2)/TiO2 was prepared simply by modifying TiO2 with Ce(SO4)(2) for acid catalysis of volatile organic chemicals, 2-propanol and cumene. The characterization of prepared catalysts was performed using FTIR, XRD and DSC. The surface area of 7-Ce(SO4)(2)/TiO2 calcined at 300 degrees C was very high (206.0 m(2)/g) compared to that of unmodified TiO2 (115.2 m(2)/g) due to the interaction between Ce(So(4))(2) and TiO2. 7-Ce(SO4)(2)/TiO2 containing 7 wt% Ce(SO4)(2) and calcined at 300 degrees C exhibited maximum catalytic activities for both reactions, 2-propanol dehydration and cumene dealkylation. The catalytic activities for both reactions were correlated with the acid amounts of catalysts measured by an ammonia chemisorption method. The role of Cc results in an increase in the thermal stability of the surface sulfate species and consequently the acid amount of Ce(SO4)(2)/TiO2 is increased. The asymmetric stretching frequency of the S = O bonds for Ce(SO4)(2)/TiO2 catalysts was related to the acidic properties and to the catalytic activity for acid catalysis to remove volatile organic chemicals, 2-propanol and cumene. (C) 2007 Elsevier B.V. All rights reserved.