CHARACTERIZATION OF ZRO2-SIO2 UNMODIFIED OR MODIFIED WITH H2SO4 AND ACID CATALYSIS

A series of ZrO2-SiO2 catalysts with various molar ratios of ZrO2/SiO2 were prepared by a coprecipitation method. The characterization of catalyst unmodified or modified with H2SO4 was performed using XRD, IR and XPS methods, and by the measurement of surface area. Mixing with amorphous SiO2 or modifying with H2SO4 shifted the transition of ZrO2 from the amorphous to tetragonal phase to a higher temperature. The catalytic activities for 2-propanol dehydration and cumene dealkylation were correlated with both acidity and acid strength of the catalyst, and the modification of catalyst with H2SO4 enhanced the catalytic activities remarkably. The difference in catalytic activities between modified and unmodified catalysts increased with increasing ZrO2 content.