CATALYTIC PROPERTIES OF SULFATED AND NONSULFATED ZRO2-SIO2 - EFFECTS OF THE SULFATION SUBMITTED BEFORE OR AFTER THE CALCINATION PROCESS, INTHE CYCLOHEXENE ISOMERIZATION REACTION
Ja. Navio et al., CATALYTIC PROPERTIES OF SULFATED AND NONSULFATED ZRO2-SIO2 - EFFECTS OF THE SULFATION SUBMITTED BEFORE OR AFTER THE CALCINATION PROCESS, INTHE CYCLOHEXENE ISOMERIZATION REACTION, Journal of molecular catalysis. A, Chemical, 135(2), 1998, pp. 155-162
Catalytic properties of sulfated and non-sulfated ZrO2-SiO2 (14% molar
in ZrO2) for cyclohexene conversion (skeletal isomerization and hydro
gen transfer) have been studied. The effects of the sulfation, submitt
ed before or after the calcination process upon textural, morphologica
l and surface acidity, have been studied. All these properties were co
rrelated to explain catalytic behaviour of the non-sulfated and sulfat
ed samples. It has been shown that catalytic activities were increased
on sulfated samples, but at the same time products of the hydrogen tr
ansfer reaction seem to increased too, lowering the selectivity of the
reaction; isomerization always predominates. For a given temperature,
when sulfation process' is submitted before calcination the catalytic
activities are lower than those obtained when the sulfation is submit
ted after the calcination process. In summary, the effect of calcinati
on temperature, the presence of sulphate groups on the surface and the
sequence of the sulfation procedure (before or after the calcination
process) seem to be important parameters on the catalytic properties f
or cyclohexene isomerization reaction exhibited by this kind of cataly
sts. (C) 1998 Elsevier Science B.V. All rights reserved.