Catalytic reforming of n-heptane over bi and trimetallic supported catalysts

Catalytic naphtha reforming is a major petroleum refining process for the production of high octane hydrocarbons in gasoline and aromatic hydrocarbons used in the petrochemical industry. The used catalysts in this process are formed from two functions: the metallic function (noble metals especially Pt) and a porous support that plays as an acidic function. The major reactions that occur are the isomerization, dehydrogenation, and dehydrocyclization [1, 2]. In the present work, a series of HMS-HZSM-5 composites impregnated by 0.6 wt% Pt catalysts promoted by different amounts of Sn, Re or Sn-Re were prepared and characterized as reforming catalysts by N2 physisorption, XRD, TGA-DSC and FT-IR. The solid catalytic activities were evaluated through reforming of n-heptane employing fixed-bed microreactor directly connected to a gas chromatograph analyzer. The catalytic evaluations show that Pt-(Re-Sn)/HMS-HZSM5 catalysts had a high activity for reforming of n-heptane. Pt-(Re-Sn)/HMS-HZSM5 have more ability compared to HMS and HZSM-5 catalysts because they have both properties of mesoporous HMS and microporous HZSM-5. The results show that bimetallic and trimetallic catalysts revealed better performance than monometallic catalysts for n-heptane reforming. The analyze of carbon deposited after the stability test shows that the coke deposition on trimetallic catalysts is lower than mono and bimetallic catalysts. The catalytic activity results indicate that the trimetallic (0.3Pt–0.3(Re, Sn))/HMS-HZSM5 catalysts are the most active towards n-heptane reforming while (0.3Pt–0.3Sn)/HMS-HZSM5 catalyst can be recognized as the worst catalyst due to its rapid deactivation.