MODIFICATION OF THE CATALYTIC PROPERTIES OF SULFATED ZIRCONIA BY ADDITION OF METAL PROMOTERS

We have studied the effects of promoting sulfated zirconia catalysts b y addition of transition metals. We have found that the addition of Ni causes an activity enhancement comparable to that caused by the addit ion of Fe and Mn. The TPD/DRIFTS results show that the catalytic activ ity does not correlate with either Bronsted or Lewis acidity. The high isomerization activity of these catalysts is explained in terms of a bifunctional mechanism in which the metal promoters are responsible fo r an enhancement in the surface concentration of olefins rather than a n enhanced acidity.