IMPORTANCE OF PRETREATMENT ON REGENERATION OF A PT-SN/AL2O3 CATALYST

The influence of pretreatment (H-2, N-2, soxhlet extraction or none) on the regeneration of a Pt-Sn/Al2O3 catalyst was studied by means of evaluation of textural properties (surface area, pore volume and pore radius distribution), amount of carbon and chlorine present and catalytic activity on n-heptane dehydrogenation of the regenerated samples. After pretreatment, the catalysts were also characterized by TPR, amount of soluble coke removed and tested with cyclohexane dehydrogenation. The chemical composition of soluble coke before and after pretreatment was determined by GC-MS. Pretreatment is an important procedure for the regeneration process and with H-2, regeneration was enhanced. The results can be interpreted by physical meaning due to the partial recovery of textural properties, and by chemical effects hue to the reduction (at least partially) of the metallic phase, incipient coke gasification and desorption-cracking processes of coke fragments.