Influence of tin content on the texture properties and catalytic performance of bi-metallic Pt–Re and tri-metallic Pt–Re–Sn catalyst for n-octane reforming

The effect of a relatively inactive metal on the texture properties and catalytic performance of bi-metallic platinum–rhenium (Pt–Re)–S/Al₂O₃–Cl catalyst was investigated. The concentration of introduced tin (Sn) varied between 0.06 and 0.32 % (weight basis). The parent and modified catalysts were characterized using the following techniques; BET, X-ray diffraction, SEM–EDX, and atomic absorption spectroscopy/inductively coupled plasma spectroscopy. The bi-metallic and tri-metallic catalysts were also screened for their activity and selectivity in the reforming of n-octane under the following conditions: T = 480 °C, p = 10 bar, WHSV = 3.3 h⁻¹ and H₂:HC = 4.5. Results showed that, on n-octane conversion, selectivity have changed favorably i.e., low selectivity to aromatics but high selectivity to iso-paraffins and olefins. In addition, less cracking products were detected and high liquid yields (LYs) were obtained. However, there is a strong and closely linear correlation between aromatics and octane number. The results of this work showed that catalyst with Sn >0.14 and <0.32 performed the best catalyst i.e., no major effect on research octane number, LY and selectivity with the addition of more Sn.