Synthesis, characterization and catalytic application of bi- and trimetallic Al-HMS supported catalysts in hydroconversion of n-heptane

Experimental and kinetic study of n-heptane isomerization on nanoporous Pt-(Re, Sn)/HZSM5-HMS catalysts

“…Therefore, these will be competing reactions. The Pt-Re/ZH catalyst has lower selectivity to aromatization and higher selectivity to cracking than the Pt-Sn/ZH catalyst (however, the differences are negligible), because the addition of Sn decreases the acidity of the support and the fraction of strong acid sites [10]. Thus, the reduction of cracking occurs on the strong acid sites.…”

“…Bi-and trimetallic catalysts form very few aromatization products. According to the Haag-Dessau mechanism, the cracking reaction proceeds through a monomolecular reaction mechanism at high temperatures and low pressures of alkanes over acidic sites [10]. In the monomolecular mechanism, the alkane protonation by Brönsted acid sites is a rate-determining step.…”

“…It must be incorporated in the industrial process to prevent the dangerous exothermic runaway produced by massive C-C bond cleavage of the feedstock in the early stages of reaction. To replace the metallic Pt-Re phase sulfidation, Sn is added to bimetallic catalysts as an inactive modifier [10,11]. It is accepted that the catalytic properties of bi-and trimetallic catalysts are based on electronic or geometric considerations [12].…”