Oxidative Dehydrogenation of Ethane on Titanium and Vanadium Oxides Deposited on SiO2 by Molecular Layer Deposition and Selective Separation of Ethylene from the Resulting Mixture

Abstract

The process of oxidative dehydrogenation of ethane on titanium-vanadium oxide catalysts deposited on silica gel by the molecular layer deposition method was studied. It was shown that the deposition of titanium and vanadium on the surface of silica occurs uniformly. When at least two layers are deposited titanium oxide crystallizes in the anatase phase while vanadium oxide remains X-ray amorphous in all catalysts. The influence of the titanium-to-vanadium ratio on the activity of the obtained catalysts was studied. It was shown that the conversion of ethane and the selectivity of its conversion into ethylene increase with increasing both the number of deposited titanium and vanadium layers and temperature. The maximum values of ethane/ethylene conversion and ethylene selectivity reach 19 and 85%, respectively. The possibility of separating ethylene and ethane in a mixture of gases leaving a catalytic reactor cooled to 30°C using a grafted ion-exchange membrane with ethylene enrichment up to 90% in three runs is demonstrated. The ethylene permeability during separation achieves 36 Barrer, and the separation factor of the ethane-ethylene mixture is 3.8.