Synthesis of high surface area zirconia and zirconia-based catalysts

Abstract

Higher surface area of zirconia catalysts were prepared with different digestion duration, doping with Si and modification with alkali. Hydrous zirconia after digestion resulted in higher surface area. The alkali-doped zirconia has up to 20 m2/g higher surface area than the undoped zirconia. However, it did not show significant differences in the selectivity to 4-methyl-1-pentene in the decomposition of 4-methyl-2-pentanol compared to pure zirconia. The incorporation of Si in zirconia resulted in a higher surface area and reached the maximum of 271 m2/g with 15 wt. % Si loading. However, the extremely high acidity led to a very poor selectivity to 4-methyl-1-pentene in decomposition of 4-methyl-2-pentanol. Modification onto silica-zirconia catalyst was carried out to obtain higher surface area of zirconia-based catalysts with acid-base properties as close to that of pure zirconia. However, the highest selectivity to 4-methyl-1-pentene over the silica-zirconia samples after alkali doping was 44 %, which is still lower than for pure zirconia, 64 %.