Five different preparation methods have been developed to synthesize titanium pyrophosphate (TiP2O7) which are active and selective catalysts for oxidative dehydrogenation of n-butane into butene and butadiene. The crystallinity, surface area, reducibility by n-butane and acid-base properties appeared different depending upon the method used. The activity of the catalysts in the oxidative dehydrogenation of n-butane appeared to depend mostly upon their redox properties whereas the selectivity was influenced by their acidic properties. Both properties seemed to be correlated to the crystallinity of the compounds but not to their surface area. (C) 2003 Elsevier Science B.V. All rights reserved.