Solid acid catalysts containing 84.5% of TiO2 and 15.5% of [Ti4H11(PO4)(9)]center dot nH(2)O (n = 1-4) have been prepared by mixing titania and phosphoric acid (88%) in the molar ratio of 1:1 and heating at 200-220 degrees C on a sand bath. Each catalyst has been characterized by IR spectroscopy, XRD, SEM/EDAX, TG and BET surface area analysis. The catalysts work very efficiently for nitration of a wide range of aromatic compounds with nitric acid (70%). (C) 2008 Published by Elsevier B.V.