DEHYDROGENATION OF ISOPROPYLIC ALCOHOL ON A CU SIO2 CATALYST - A STUDY OF THE ACTIVITY EVOLUTION AND REACTIVATION OF THE CATALYST/

The activation-deactivation behaviour of a Cu/SiO2 catalyst during iso propyl alcohol (IPA) dehydrogenation to acetone has been studied. Simu ltaneous reduction and sintering processes are responsible for the act ivation-deactivation behaviour observed. The reducing H-2 atmosphere i mpulses the transformation of CuO into Cu-0 and at the same time the s intering of the Cu-0 phase formed. The reoxidation treatment in air at 573-673 K is able to regenerate a finely dispersed CuO phase from the sintered Cu-0 phase. As a result, the active phase is redispersed and the dehydrogenation activity is recovered. The results indicate the e xistence of two CuO phases on the catalyst, with different properties. The CuO phase with a low reduction temperature, a small particle size and a poor crystallinity, is the one responsible for the appearance o f the finely dispersed Cu-0, whxich is the active phase for this react ion.