Effect of Al Content on the Isomerization Performance of Solid Superacid Pd–S2O82−/ZrO2 –Al2O3

Abstract

The effect of Al content on the performance of the Pd–S2O82−/ZrO2–Al2O3 solid superacid catalyst was studied using n-pentane isomerization as a probe reaction. The catalysts were also characterized by X-ray diffraction (XRD), Fourier transform Infrared (FTIR), specific surface area measurements (BET), thermogravimetry–differential thermal analysis (TG–DTA), H2-temperature programmed reduction (TPR) and NH3 temperature-programmed desorption (NH3-TPD). The Pd–S2O82−/ZrO2–Al2O3 catalyst made from Al2O3 mass fraction of 2.5% exhibited the best performance and its catalytic activity increased by 44.0% compared with Pd–S2O82−/ZrO2. The isopentane yield reached 64.3% at a temperature of 238°C, a reaction pressure of 2.0MPa, a space velocity of 1.0h−1 and a H2/n-pentane molar ratio of 4.0. No obvious catalyst deactivation was observed within 100h.