No abstract

Five samples of Al 2 O 3 /AlPO 4 (Al/P = 1.75) and Cr 2 O 3 -loaded Al 2 O 3 / AlPO 4 (wt% Cr 2 O 3 = 5-25) were prepared. The catalysts were obtained by thermal treatment of the corresponding samples in air at 823 K and were characterized using XRD and DTA techniques. The textural properties (surface area, total pore volume and mean pore radius) were determined from nitrogen adsorption data obtained at 77 K. The acidic properties of all the samples were measured calorimetrically. The catalytic conversion of isopropanol was studied using a microcatalytic pulse technique. No spinel structure was detected by both XRD and DTA techniques and only Cr 2 O 3 was detected for samples containing 15 wt% chromia. Loading Al 2 O 3 /AlPO 4 with Cr 2 O 3 led to significant changes in the texture, surface acidity and catalytic activity of the prepared catalysts. Al 2 O 3 /AlPO 4 catalysts exhibit no dehydrogenation activity, whereas loading with Cr 2 O 3 favoured the dehydrogenation of isopropanol to acetone.