Characterization of titanium sulfate supported on zirconia and activity for acid catalysis

Titanium sulfate supported on zirconia catalysts were prepared by impregnation of powdered Zr(OH)(4) with titanium sulfate aqueous solution followed by calcining in air at high temperature. For high Ti(SO4)(2) loading samples, orthorhombic and triclinic phases of zirconium sulfate were formed by the reaction between titanium sulfate and zirconia during the catalyst preparation. The addition of titanium sulfate to zirconia shifted the phase transition of ZrO2 from amorphous to tetragonal to higher temperature because of the interaction between titanium sulfate and zirconia, and the specific surface area and acidity of catalysts increased in proportion to the titanium sulfate content up to 5 wt % of Ti(SO4)(2). 5-Ti(SO4)(2)/ZrO2 calcined at 600 degreesC exhibited maximum catalytic activities for 2-propanol dehydration and cumene dealkylation. The catalytic activities for both reactions, 2-propanol dehydration and cumene dealkylation, were correlated with the acidity of catalysts measured by the ammonia chemisorption method. Ti(SO4)(2)/ZrO2 due to the incorporation of titanium component exhibited higher catalytic activity for the 2-propanol dehydration reaction than Zr(S04)(2)/ZrO2 without titanium.