Abstract

A series of sulphated zirconia dopped by cobalt oxide (CoSZ) catalysts were prepared. The structural characteristics were investigated by means of powder X-ray diffraction (XRD) Scanning electron microscope (SEM) and transmission electron microscope (TEM) while the textural properties were determined from low temperature adsorption of N2 at -196 oC. The surface acidity was measured with non aqueous titration of n-butylamine in acetonitrile. The catalytic activity of the prepared catalysts was tested by Peckman condensation for production of cumarin. The XRD data indicated that, increasing Co content., the tetragonal phase increased up to 10 % Co, The surface area was found to increase with increasing of Co content upto 10% and then decreased, Also, by increasing Co content, the surface area was found to increase upto 600oC and then decreased. The incorporation of cobalt into SZ increases the surface acidity of the catalysts. Moreover, the acidity was found to increase with increasing the calcinations temperature from 400 to 600 oC and then decreased. The activities of these catalysts were tested for synthesis of 7-hydroxy 4-methyl cumarin (cumarin pechman synthesis). The higher activity of these catalysts was attributed to its higher acidity. It was concluded that, the catalytic activity was strongly influenced with the textural properties and surface acidities of the catalysts investigated

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