ZrO2/SiO2 mixed oxides as catalysts for alcohol dehydration

The mixed oxides, ZrO2/SiO2, with different compositions were synthesized by the sol–gel method of hydrolyzing zirconium(IV) propoxide and tetraethyl orthosilicate in n-butanol solution in the presence of 2,4-pentanedione as complexing agent. The surface area and pore volume of the catalysts were strongly influenced by the composition with ZrO2/SiO2 (23 mol%) giving the largest pore volume and ZrO2/SiO2 (32 mol%), the largest surface area. Under the present synthesis condition, the maximum miscibility of ZrO2/SiO2 seemed to be 23–32 mol%, forming a highly developed mesoporous texture. The catalyst ZrO2/SiO2 (32 mol%) showed the highest catalytic activity for iso-propanol dehydration with a selectivity of 100%.