The synthesis of methyl tert-butyl ether (MTBE) from methanol and isob
utylene in a gas-solid heterogeneous system over sulfur-promoted zirco
nias calcined at different temperatures between 400 and 700 degrees C
was studied. The reaction temperature was varied in the range 90-110 d
egrees C, and methanol to isobutylene molar ratios were changed from 1
.0 to 1.3. The catalyst acidity was a direct function of the sulfur lo
ad, in turn a consequence of the calcination temperature. Temperature
programmed reduction experiments allowed us to observe that the sulfur
reduction process is different according to the calcination temperatu
re. The highest activity was observed on the sample calcined at 600 de
grees C, which was comparable with that of the reference catalyst Ambe
rlyst 15 under the same conditions. A direct relationship between cata
lyst acidity and conversion was not observed. The injection of water c
ompletely poisoned the catalyst activity in a reversible manner. (C) 1
997 Elsevier Science S.A.