III International Conference

NANOSTRUCTURED MATERIALS BASED ON ZIRCONIAPP-II-84Moroz E.M., Strizhak P.E. 1 , Kosmambetova G.R. 1 , Zyuzin D.A., Kolko V.P.,Konstantinova T.E. 2 , Tusikov F.V., Guralsky A.V. 1 , Vlasenko N.V. 1Boreskov Institute of Catalysis SB RAS, Novosibirsk, Russia1 Pysarzhevskii Institute of Physical Chemistry of the NAS, Kiev, Ukraine2 Galkin Physico-Technical Institute of the NAS, Donetsk, UkraineE-mail: Emoroz@catalysis.ruNanostructured materials based on zirconium oxide are of great interest due to variety oftheir polymorphism, chemical and physical stability, and ion conductivity. That determinespossible applications of those materials as catalysts for red-ox processes, particularly, for fuelcell applications. Properties of zirconia-based materials could be regulated by incorporatingsmall quantities of cations with charge 2+ or 3+. Particularly, that stabilizes low temperaturecubic or tetragonal phases which are characterized by high dispersity. We investigatedzirconium oxides obtained by two methods:• Treatment of the ittrium modified zirconium hydroxide by the pulse-microwavefollowed by calcination at different temperatures (300-1000 o C)• Hydrothermal synthesis of zirconia followed by calcination at temperatures upto 1000 C.Obtained oxides were characterized by transition electron microscopy (TEM), X-raydiffraction (XRD), small-angle X-ray scattering (SAX), BET, and vacuum thermogravimetryof NH 3 and CO 2 with stepwise heating regime .For ittrium stabilized ZrO 2 it was shown that increasing calcination temperature up to400 C leads to crystallization of non-sintered particles of tetragonal phase. Further increase oftemperature causes formation of nanostructured systems.A mild calcination at 500 o C of zirconia, obtained by hydrothermal synthesis, leads toformation of pure tetragonal phase. At further temperature increasing up to 600-650 o C the(111) “cubic” reflection reappears in XRD patterns. Modeling of XRD patterns revealed thatthis phenomenon could be explained by polysynthetic (001) twinning.Functional properties of active centres of nanosize zirconia samples were characterized inthe CO oxidation. It was found, that nanosized zirconia obtained at 1000 o C demonstrates thehighest activity in the CO oxidation. Obviously this effect is related to structural properties ofzirconia, formed under the microwave treatment.317