Catalytic Study and Kinetic Modeling of the n-Heptane Isomerization over Pt/Al-HMS/HZSM-5 Hybrid Catalysts

Abstract

Pt/Al-HMS/HZSM-5 catalysts with various amounts of Si/Al ratios were evaluated for the n-heptane isomerization reaction at 200–350 °C. To study the catalyst characterizations, X-ray diffraction (XRD), X-ray fluorescence (XRF), Fourier transform infrared (FTIR) spectroscopy, ultraviolet–visible diffuse reflectance spectroscopy (UV–vis DRS), temperature-programmed desorption of ammonia (NH3-TPD), FTIR of adsorbed pyridine (Py-IR), H2 chemisorption, nitrogen adsorption–desorption, and thermogravimetric analysis (TGA) techniques were performed. Kinetics of n-heptane isomerization was investigated under various hydrogen and n-heptane pressures. For more studies, two kinetic models have also been selected and tested to describe the kinetics for this reaction. Both used models, the power law and Langmuir–Hinshelwood provided a good fit toward the experimental data and allowed for the determination of the kinetic parameters. According to these studies, the Pt/Al(45)-HMS/HZSM-5 catalyst has better properties than ...