Effect of Selenium Additives on the Physicochemical and Catalytic Properties of VMoTeNbO Catalysts in the Oxidative Dehydrogenation of Ethane

The effect of selenium additives on the structure, physicochemical, and catalytic properties of VMoTeNbO catalysts in the oxidative dehydrogenation of ethane was studied. It was shown that the introduction of selenium on the first stage of catalyst preparation (mixing of the initial solutions) makes it possible to obtain in the course of subsequent heat treatment highly crystallized samples, which mainly include the M1 phase. Despite the fact that, in the process of heat treatment, selenium is completely removed from the samples, the prepared catalysts differ markedly from unmodified samples and demonstrate a higher selectivity to ethylene at a conversion of ethane of 93%. The observed effects are due to the influence of selenium on the process of formation of the M1 phase resulting in increase of its crystallinity.