Normal Heptane Reforming of Promoted Platinum Composite Catalysts: Preparation, Characterization and Catalytic Performance

Abstract

Pt/Zr(x)-HMS/HZSM-5 catalysts with different ratios of Silicium/Zirconium (denoted as x) were studied for normal heptane reforming at 350-450 ^°C temperature range. For this purpose, the properties of the catalysts such as X-ray diffraction, X-ray fluorescence, Fourier-transform infrared spectroscopy, Ultraviolet–visible diffuse reflectance spectroscopy, NH₃-temperature programmed desorption, H₂ chemisorption, N₂ adsorption-desorption, and thermal gravimetric analysis were used. The results show that the produced Pt/Zr(x)-HMS/HZSM-5 catalysts have highly efficient performance for n-heptane reforming with a high isomers selectivity up to 69.4% (mono branched isomers = 31.8% and multi branched isomers = 37.6%) and a good selectivity to aromatic compounds (especially toluene = 6.9%), in spite of an appropriate selectivity to light products. It was revealed that the proper structure of these catalysts facilitates the reforming of n-heptane. According to these results, Pt/Zr(35)-HMS/HZSM-5 catalyst showed the favorable properties for this investigated catalytic process.