Effects of Cerium Doping on Pt–Sn/Al<sub>2</sub>O<sub>3</sub> Catalysts for <i>n</i>-Heptane Reforming
Chang Lin, Huihua Pan, Zixu Yang, Xiaolin Han, Pengfei Tian, Ping Li, Zhikai Xiao, Jing Xu, Yi‐Fan Han
Abstract
A series of trimetallic Pt–Sn–Ce catalysts supported on chloride Al2O3 was prepared by a sequential impregnation method and applied for n-heptane reforming and characterized by several techniques, including N2 physiosorption, transmission electron microscopy, X-ray diffraction, hydrogen temperature-programmed reduction, CO chemisorption, ammonia temperature-programmed desorption, pyridine desorption Fourier-transform infrared spectroscopy, and in situ diffuse reflectance infrared Fourier transform spectroscopy. We have demonstrated that the introduction of Ce can promote isomerization reactions by suppressing undesirable hydrogenolysis reactions, whereas it does not significantly influence the dehydrocyclization reactions. The characterization results show that CeOx can enhance the reducibility of Pt species via enhancing the Pt dispersion. In addition, Ce increases the proportion of medium-strength acid sites, which does not only promote isomerization activity, but also suppresses the undesirable reactions such as hydrogenolysis and cracking.