Sulfated titania was prepared by in situ gelling titanium alkoxide with sulfuric acid and by impregnation with ammonium sulfate of titania gels, hi annealing gels at 600 C, the BET specific surface areas were of 46 and 177 m(2)/g for sulfuric and ammonia sulfate preparations, respectively. XRD patterns showed for "in situ" preparation anatase (92%) and rutile phases (8%), while for ammonium sulfate sample only anatase phase was observed, FTIR-pyridine adsorption identified Bronsted (B) and Lewis (L) sites for titania impregnated with ammonium sulfate, however, only Lewis (L) sites were identified in titania prepared with sulfuric acid. In the isopropanol conversion, similar activities were obtained. However, in sulfuric preparation the selectivity was 22 and 78 mol% to propene and isopropyl ether, respectively, while in ammonium sulfated catalyst the selectivity was 70 mol% to propene and 30 mol% to isopropyl ether. The results are discussed with regards to the acidity requirements explaining the role of acid sites in the selectivity. (C) 2004 Elsevier B.V. All rights reserved.