New solid superacid catalyst prepared by doping ZrO_2 with Ce and modifying with sulfate and its catalytic activity for acid catalysis

摘要

A new solid superacid catalyst,Ce-ZrO_2/SO_4~(2-)was prepared simply by doping ZrO_2 with Ce and modifying with sulfate simultaneously.The characterization of prepared catalysts was performed using FTIR,XRD and DSC.The surface area of 5Ce-ZrO_2/SO_4~(2-)calcined at 650 deg C was very high(121.2 m~2/g)compared to that of undoped and only sulfated ZrO_2(56.0 m~2/g).This high surface area of Ce-ZrO_2/SO_4~(2-)was due to the doping effect of Ce,which makes zirconia a stable tetragonal phase as confirmed by XRD.5Ce-ZrO_2/SO_4~(2-)containing 5 wt.% Ce(SO_4)_2 and calcined at 650 deg C exhibited maximum catalytic activities for both reactions,2-propanol dehydration and cumene dealkylation.The catalytic activities for both reactions were correlated with the acidity of catalysts measured by the ammonia chemisorption method.The role of Ce was to form a thermally stable solid solution with zirconia and consequently to give high surface area and acidity of the sample.