Comparison of activity and stability of platinum-zeolite/silica catalysts in the normal heptane isomerization process

In the conducted study, the performance of various catalysts for the isomerization of n-heptane has been investigated. A series of platinum (Pt) catalysts supported on ZSM-۵/HMS, Cr/Zr(x)-HMS, MoOx/ZrO۲-HMS, and Pt/Silica were analyzed for n-heptane isomerization under different conditions in terms of structure, acidic properties, and catalytic stability. These catalysts were characterized using essential techniques, including XRD, XRF, NH۳-TPD, FTIR, H₂ chemisorption, nitrogen sorption, and TGA. The results showed that these catalysts exhibit suitable micro/mesoporous properties, which help increase the conversion and selectivity of i-C۷ isomers. For the Pt/ZSM-HMS catalyst, the highest i-C۷ isomer selectivity (Yo,^%) was observed at Y..°C. In Pt-Cr/Zr(x)-HMS catalysts, increasing the Cr/Zr ratio improved catalytic activity and increased the conversion to ۷۵% at Y.. °C. Pt-MoOx/ZrO۲-HMS catalysts demonstrated the best selectivity for i-C۷ isomers (^),^%) with no production of aromatic compounds at Y.. °C. Additionally, the results for the Pt/SBA-۱۰ catalyst showed that it provided the highest conversion and isomerization selectivity. Finally, this study investigated the isomerization process and the effects of temperature, pressure, and reactant concentration on catalyst behavior, revealing that kinetic effects and catalyst acidity play a crucial role in their performance.

کلیدواژه ها:

Isomerization ، normal heptane ، platinum ، zeolite