Composition, Physicochemical Properties, and Catalytic Properties of the Products of Thermal Treatment of Al2(SO4)3 · 18H2O
Kinetics and Catalysis
, E-ISSN: 1608-3210
Boreskov Institute of Catalysis SB RAS
The influence of the conditions of thermal treatment of Al-2(SO4)(3). 18H(2)O on the properties of the products formed is studied by a complex of physicochemical methods. The catalytic activity of these products in the model reactions of L-butene isomerization into 2-butenes and dehydration of isobutanol is investigated. It is shown by Al-27 MAS NMR that the coordination sphere of aluminum changes upon calcination: water molecules are substituted by hydroxyl and sulfate groups. The processes of hydrolysis and condensation of AlOH and SOH groups leading to the substitution of all ligands by the sulfate groups are stopped at temperatures below 250 degrees C. The specific surface area and catalytic activity of aluminum sulfates in the reactions under study are governed by the conditions of thermal treatment. The sample of anhydrous crystalline Al-2(SO4)(3) calcined at 400-450 degrees C exhibits the highest catalytic activity.