Structural and Catalytic Properties of Sulphated Zirconia doped by Zn Oxide

SULFATED zirconia (SZ) and zinc supported sulfated ……zirconia (Zn/SZ) catalysts were synthesized, characterized and evaluated by coumarin synthesis reaction. The reaction was carried by reacting resorcinol and ethyl acetoacetate with a molar ratio 1:2 respectively. The investigated SZ and Zn/SZ catalysts were prepared by the simple impregnation method with an aqueous solution of H₂SO₄ as a precipitating agent, followed by drying in rotary and finally calcined at 600 ^oC for 3 hrs. The physicochemical properties of the investigated catalysts were characterized by the x-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscope (TEM) and potentiometric titration to characterize the number and the strength of the acid sites. The 6%Zn/SZ catalyst possessed the maximum catalytic activity as well the number of acid sites. Increase of the tetragonal phase content in ZrO₂ increases the catalytic activity.