Influence of O-2 and O-3 Regeneration on the Metallic Phase of the Pt-Re/Al2O3 Catalyst

PIECK, CL; QUERINI, CA; PARERA, JM

APPLIED CATALYSIS, A. GENERAL

Año: 1997 vol. 165 p. 207 - 218

The influence of the regeneration with oxygen or ozone on the metallic function activity of the Pt-Re/AI203 catalyst prepared by catalytic reduction is studied. The interaction between Pt and Re is higher when activation is carried out by direct reduction. However, calcination at 450°C leads to a segregation of metals. The regeneration carried out with diluted 0 20 2 destroys the metallic interaction producing segregation of Pt and Re, while the regeneration with 03 at low temperature avoids such segregation to a large extent. Ozone not only bums coke off, but also modifies its burning characteristics as measured by temperature programmed oxidation technique (TPO) with 6% O2]N 2. It was found that after the 03 treatment, the coke left on the catalyst burns at lower temperatures if compared to the coke without 03 treatment. Therefore, a regeneration treatment can be carried out at low temperatures by combining a first step with 03 followed by a second one with O~ at lower temperatures than those needed in conventional regeneration procedures.O2]N 2. It was found that after the 03 treatment, the coke left on the catalyst burns at lower temperatures if compared to the coke without 03 treatment. Therefore, a regeneration treatment can be carried out at low temperatures by combining a first step with 03 followed by a second one with O~ at lower temperatures than those needed in conventional regeneration procedures.