Dehydrogenation of Cyclohexane in Relation to Some Textural and Catalytic Properties of Ni/Al2O3 and Co/Al2O3 Catalysts

Abstract

Ni/Al2O3 and Co/Al2O3 catalysts of different compositions have been prepared. Their structural properties were determined using X-ray diffraction and differential thermal analysis. The textural properties of these catalysts were determined from nitrogen adsorption at 77 K. The catalysts were reduced with hydrogen at 673 K and the adsorption of hydrogen on the reduced catalysts was measured at 320 K. Dehydrogenation of cyclohexane at flow rates of 10–30 ml/min and at 633–723 K was investigated. The loading of alumina with metal oxides leads to changes in the textural properties depending on the degree of loading and on the loaded metal oxide. The adsorption of hydrogen allowed the determination of important catalytic parameters. Dehydrogenation of cyclohexane on the investigated catalysts followed fraction order kinetics. The dehydrogenation activity has been related to the H2 uptake and to the extent of metal dispersion on the support.