LIQUID-PHASE DEHYDROGENATION OF CYCLOHEXANOL WITH SUPPORTED NOBLE-METAL HYDROGENATION CATALYSTS

Cyclohexanol dehydrogenation and cyclohexanone hydrogenation were performed with suspended noble metal catalysts. The orders of initial dehydrogenation rates, Pd>Rh~Pt≫Ru and Rh>Pd~Pt≫Ru obtained for the catalysts supported on carbon and alumina respectively, were different from those of hydrogenation. In cyclohexanol the suspended states of carbon-supported catalysts were stable, with the dehydrogenation activity retained for a long period. The platinum catalysts were the most active for hydrogenation. Contrast between the palladium and ruthenium catalysts observed in the behaviors of dehydrogenation and hydrogenation is particularly interesting for developing good liquid-phase dehydrogenation catalysts. © 1990, The Chemical Society of Japan. All rights reserved.