ISOMERIZATION OF N-BUTANE ON PT SO42--ZRO2 AND MECHANICAL MIXTURES OFPT/AL2O3+SO42--ZRO2/

The effect of the incorporation of a metallic phase (Pt) into a supera cid catalyst (SO42--ZrO2) for n-butane isomerization was studied. The convenience of supporting Pt directly on the superacid or on alumina a nd of using the physical mixture as a catalyst was also analyzed. Pt s upported on SO42--ZrO2 has the same activity as SO42--ZrO2, but the st ability is increased. The bifunctional reaction mechanism is not opera ting because Pt does not have metallic properties due to a strong inte raction with the support under the experimental conditions of reductio n (573 K). When Pt is supported on Al2O3 and mixed mechanically with S O42--ZrO2, the activity and stability are increased due to the operati on of the bifunctional mechanism. (C) 1995 Academic Press, Inc.