Investigation of n-heptane hydroisomerization over alkali-acid-treated hierarchical Pt/ZSM-22 zeolites

Abstract

The design of various hierarchical and morphology ZSM-22 zeolite catalysts is attempted through the post-treatment of different concentrations of NaOH and subsequently, deals with HCl solution including fluosilicic acid (H2SiF6)...

Hydroisomerization of <i>n</i>-Pentane over Zn-Fe-S<sub>2</sub>O<sub>8</sub><sup style="margin-left:-6px;">-2</sup>/ZrO<sub>2</sub>-Al<sub>2</sub>O<sub>3</sub> Superacid Catalyst: Activity, Surface Analysis and the Investigation of Deactivation and Regeneration

“…The fresh catalyst showed a high initial activity, but poor stability. These observations are similar to those reported previously [31].…”

“…After rearrangement, these carbenium ions desorb from the acid sites as alkenes and are hydrogenated on the metal sites yielding saturated reaction products. With catalysts lacking acid or metal sites, the corresponding process becomes the rate-determining step [31]. Therefore, the synergistic interaction between metal sites and acidic sites plays an important role in isomerization.…”

The effect of potassium on the balance of metal–acid site in Pt/Al2O3 catalysts and their n-hexane dehydrogenation performance

“…All samples show three peaks in the range of 150-550 1C, which can be categorized into three groups (weak acid: o250 1C; medium acid: 250-350 1C, and strong acid: 4350 1C). 35 Compared with the Al 2 O 3 support, the peak proportion of weak acid among the Pt/Al 2 O 3 catalysts decreased from 23.6% to 18.9%, while the proportion of medium-strong and strong acids increased. After doping K into the Pt/Al 2 O 3 catalyst, the change in acidity shows an opposite trend to that after Pt introduction.…”

Study on the preparation and n-heptane isomerization performance of MoOx-Pd/Ce-MCM-48 catalyst

“…The mechanism of n-heptane isomerization reaction has been studied in many literature, 3,16,43,45 Based on the experimental results and literature, we proposed that the isomerization reaction mechanism of n-heptane on MoO x Pd/Ce-M catalyst followed a classical bifunctional mechanism (Fig. 11).…”