Effect of Aging Temperature of Support on Catalytic Performance of PtSnK/Al2O3 Propane Dehydrogenation Catalyst

Abstract

Catalytic dehydrogenation of propane to propylene is one of the vital processes in the petrochemical industry, primarily because of the extensive use of propylene as one of the most crucial building blocks for the production of a wide range of essential chemicals and polymers. In this study, the nano-structural PtSnK was supported on an alumina carrier prepared by an environmentally friendly modified oil-drop method. By adjusting the aging temperature of the alumina carrier, the physical and chemical structural properties of the catalyst can be modulated, and then affect the propane dehydrogenation performance of the catalyst. The effects of aging temperature on the structure and chemical properties of the support and catalyst were studied by N2 sorption, XRD, TEM, TG, NH3-TPD, H2-TPR, CO pulse adsorption, and XPS techniques. As the aging temperature increases, the spherical particles gradually changed from a worm-like structure to a needle or rod-like structure. At the same time, the pore size and volume increase, the pore size distribution becomes wider. Besides, the aging temperature also affects the interaction between the supported metal and the alumina support. The higher aging temperature can inhibit the reduction of SnOx species and enhance the interaction between Sn species and the alumina support. All these features together ensure excellent propane dehydrogenation performance and high stability of the catalyst. When the aging temperature is 140 °C, the PtSnK/Al2O3 catalyst exhibits excellent catalytic propane dehydrogenation performance, with an average propane conversion of 36.5%, average propylene selectivity of 96.5% during 50 h reaction. We reported the modulation of the aging temperature on the physical and chemical properties of the PtSnK/Al2O3 propane dehydrogenation catalyst when the alumina carrier is prepared by the oil-drop method. In order to obtain an optimal propane dehydrogenation catalyst, an optimum aging temperature is preferred to provide a catalyst with high propane conversion, propylene selectivity and catalyst stability.