الفهرس | Only 14 pages are availabe for public view |
Abstract Part I] Acid-base Catalysts & base Catalysis : 1-Calcinations of DAHC at 770 K for 5 h results in highly stoichiometric ceO2 crystallized in fluorite structure . 2-Y-Al2O3 surfaces also have at least two different types of lewis acid sites of different acidities, as well as different basic sites , in addition to the presence of surface –OH groups of different structures and acid – base properties. Pat II] Superacid Catalysts & Catalysis : 1- Calcinations of Zirconium hydroxide at 660 k leads to formation of a mixture of monoclinc and tetragonal zro2 phases, while following calcinations at > 770 k only monoclinc was formed . 2-The presence of sulfate ion on zirconia prepared from hydroxide increases the surface area and the stability of the tetragonal phase at high temperatures. While the presence of sulfate on Zro2 prepared from crystalline oxide shows no effect on surface area and crystallization. |