الفهرس | Only 14 pages are availabe for public view |
Abstract Mesostructure tin oxide (m-SnO2) was synthesized using a cationic surfactant (cetyltrimethyl-ammonium bromide, CTAB) as the organic supramolecular template. After calcination at 550oC, m-SnO2 was modified with different loading of Phosphomolybdic acid PMA/m-SnO2 and Phosphoric acid PO43-/m-SnO2 and calcined at 400oC. The 25PMA/m-SnO2 and 3PO43-/m-SnO2 samples were calcined at 400, 450, 550 and 650oC to study effect calcination temperature on chemical and physical properties of catalysts. The catalysts were characterized by X-ray diffraction analysis (XRD), thermal analysis (TGA and DTA), FTIR spectra and transmission electron microscopy (TEM). The surface area and pore diameter of catalysts were evaluated using the N2 adsorption isotherms at -196oC. The surface acidity was measured with nonaqueous titration of n-butyl amine in acetonitrile. The catalytic activity was tested by the Pechmann reaction of PMA/m-SnO2 and Synthesis of hydroquinone diacetate of PO43-/m-SnO2. The reusability of the catalysts shows that the catalysts can be used several times without significant loss in activity. |