Synthesis of hexagonally packed porous titanium oxo-phosphate Juliette Blanchard a,1 , Ferdi Sch uth a, * , Philippe Trens b , Michael Hudson b a MPI f ur Kohlenforschung, Kaiser-Wilhelm-Platz 1, 45466 M ulheim, Germany b Department of Chemistry, University of Reading, Whiteknights, Box 224, Reading, Berkshire GB-RG6 6AD, UK Received 9 August 1999; received in revised form 9 March 2000; accepted 9 March 2000 Abstract The synthesis of a hexagonally packed porous titanium oxo-phosphate from titanium isopropoxide, sulfuric acid and alkyltrimethylammonium bromide is reported. XRD and TEM have been used to characterize the mesostructure that forms at ambient temperature as well as the calcined material. The eect of the alkyl chain length of the surfactant has also been studied. The N 2 -sorption isotherms of the samples calcined at 350°C are characteristic of super-microporous materials. The pore diameters and the surface areas of the materials, evaluated from the N 2 -sorption isotherms and unit cell parameters, indicate pore diameters of about 2±3 nm and surface areas around 350 m 2 /g. Ó 2000 Elsevier Science B.V. All rights reserved. Keywords: Titania; Mesoporous; Synthesis; Phosphate; MCM-41 1. Introduction Since the discovery of a family of silicon-based mesoporous materials by the Mobil Oil Corpora- tion [1,2] there has been a number of attempts to synthesize mesoporous transition metal oxides which are analogous to MCM-41 [3]. These ma- terials have potential applications as high surface area catalysts, adsorbents or as host lattices for quantum size particles. Soon after the discovery of the siliceous materials, the ®rst lamellar and hex- agonal composite mesostructures were prepared based on transition metal polyanions or polyca- tions associated, respectively, with positively or negatively charged surfactants [4,5]. None of these mesostructures were, however, stable upon re- moval of the surfactant, either by calcination or by extraction at ambient temperature. The ®rst suc- cessful surfactant removals were reported by An- tonelli and Ying upon acid extraction of neutral surfactant from a mesostructure synthesized using the ligand-assisted templating method [6], or upon calcination of a TiO 2 -based mesostructure [7]. The latter has been questioned by Putman et al. who have only observed the lamellar phase when using similar experimental conditions [8]. Stone and Davis have, however, recently managed to obtain Microporous and Mesoporous Materials 39 (2000) 163±170 www.elsevier.nl/locate/micromeso * Corresponding author. Address: Max-Planck-Institute fur Kohlenforschung, Kaiser Wilhelm Platz 1, 45470 Mulheim, Germany. Fax: +49-208-306-2995. E-mail address: schueth@mpi-muelheim.mpg.de (F. Schu È th). 1 Present address: Laboratoire de R eactivit e de Surface, Universit e Pierre et Marie Curie, 4 Place Jussieu, F-75252 Paris, France. 1387-1811/00/$ - see front matter Ó 2000 Elsevier Science B.V. All rights reserved. PII:S1387-1811(00)00192-X