Dehydration and oxidative dehydrogenation of ethanol over SBA-15 based catalysts prepared by sol-gel and hydrothermal methods

Abstract

In this present study, characteristics and catalytic properties of zirconium (Zr) and bimetal (Zr and La) containing in SBA-15 catalysts and different VOx/SBA-15 catalysts were determined and well related. The study was divided into three parts. Regarding to the first part, zirconium (Zr) and bimetal (Zr and La) containing in SBA-15 synthesized by sol-gel and hydrothermal methods were compared. The results showed that the incorporation of Zr and bimetal (Zr and La) had an effect on the textural properties of both synthesized SBA-15 catalysts. Surface acidity in the SBA-15 suggests new active sites, especially Brønsted acid type. In the second part, all SBA-15 catalysts synthesized by both methods were first used as catalysts for the catalytic dehydration of ethanol to ethylene. The result shows that the performance of these SBA-15 supported catalysts in ethanol dehydration is also related with the alteration of surface acidity caused by the introduction of Zr and Zr-La. According to further modified of these catalysts, zirconium (Zr) and bimetal (Zr and La) containing in SBA-15 catalysts were selected to study in the third parts with vanadium oxide or VOx species modification in order to be used in non-oxidative dehydrogenation and oxidative dehydrogenation of ethanol. It is worth noting that isolated monomeric VOx species, as well as the amounts of weak basic sites essentially played important role in non-oxidative dehydrogenation and oxidative dehydrogenation of ethanol to acetaldehyde.