UDC 544.01 V. L. Struzhko, E. V. Senchilo, and V. G. Il'inWe have used X-ray phase analysis, temperature programmed desorption of argon, and IR spectroscopy to study the conditions and characteristics of formation and the adsorption and acidic properties of mesoporous phosphated zirconium dioxide. We have established that treatment of a mesostructural and mesoporous hydrogel of zirconium hydroxide with a solution of orthophosphoric acid not only promotes stabilization of the mesostructure and the texture when detemplated, but also functionalization of the zirconium dioxide surface.Key words: phosphated mesoporous zirconium dioxide, preliminary acid treatment, stabilization of a mesophase, acidity, thermal stability.Recently there has been increased interest in zirconium dioxide in connection with design of fuel cells with a ceramic oxide electrolyte (SOFCs, solid oxide fuel cells), based on ZrO 2 and stabilized by yttrium oxide, for direct conversion of the chemical energy of the fuel to electrical energy [1]. Furthermore, ZrO 2 is used as an effective adsorbent, an ion exchanger with controllable sorption properties, and a support for catalytically active materials for use in acid-base and oxidation-reduction processes. We know that the metastable tetragonal modification of ZrO 2 may have an extended surface, but under high-temperature operating conditions its conversion occurs to the thermodynamically stable monoclinic modifications. This may lead to a decrease in the specific surface area S sp and the porosity of the zirconium dioxide, which is an obstacle for its use as a support for catalysts used in high-temperature reactions. And only recently have new methods appeared for doping ZrO 2 with small additions of other oxides (Si, La, Sc, Y, etc.), allowing us to obtain samples which even after high-temperature treatment retain a sufficiently high value of S sp (up to 100 m 2 /g). Furthermore, there is another way to obtain zirconium dioxide with an even more extended surface: the template method. However, despite the intensive study of mesoporous molecular sieves (MMSs) of the MCM-41 type, including those based on zirconium dioxide (synthesis, mechanism of structure formation, modification, properties, and application), so far it has not been possible to obtain ZrO 2 having a thermally stable, uniformly mesoporous structure like silica MMSs. From analysis of papers devoted to synthesis and study of mesoporous oxides of transition metals and also tin dioxide, it follows that by using different synthesis conditions (composition of the reaction mixture, hydrothermal treatment time and temperature, chemically different templates), some authors have been able to obtain raw materials with a spatially ordered mesostructure, which however breaks down upon detemplating (400°C) [2]. Breakdown of the mesophase was connected by the authors of [3] with incomplete condensation of the framework former and the occurrence of oxidation-reduction reactions during detemplating, and also with some characteristic intrinsic feature...
