The dehydration and dehydrogenation of isopropanol has been studied on sintered, powdered, and pelleted chromia-alumina catalysts. With the powdered and pelleted catalysts the extent of dehydrogenation passes through a maximum as the temperature is raised from 380 °C keeping the contact time constant, while with the sintered catalyst there is a normal increase in extent of dehydrogenation with increase in temperature. The type of semiconductivity and the pore distribution of these catalysts have been investigated. The observed results for the dehydrogenation are discussed and explained on the basis of the semiconductor characteristics and texture of the catalysts. © 1969.