O2 and O3 regeneration of PtReSn/Al2O3 and PtReGe/Al2O3 naphtha reforming catalysts prepared by catalytic reduction

The deactivation and regeneration of naphtha reforming PtReGe/Al2O3 and PtReSn/Al2O3 catalysts prepared by catalytic reduction were studied. The extent and nature of coke deposition as determined by TPO were related to catalyst properties such as dispersion, acidity and Cl content. The PtReSn catalyst was the most resistant to coke deactivation. Regeneration was performed by calcination in oxygen at 450 degrees C or ozone at 125 degrees C at variable regeneration times. Regenerated catalysts were evaluated by cyclopentane hydrogenolysis, cyclohexane dehydrogenation and n-heptane reaction tests. Regeneration by oxygen burning-off was the most effective for decoking. However, oxygen combustion produced more segregation of the metal function than ozone regeneration. With the regeneration conditions used in this work, the original acidity of the catalysts cannot be recovered. (C) 2010 Elsevier B.V. All rights reserved.