Te-doped MoV-Oxide (M1 phase) for ethane ODH. The role of tellurium on morphology, thermal stability and catalytic behaviour

Abstract

[EN] Undoped and Te-doped MoV-Oxide (M1 phase) catalysts have been prepared hydrothermally (Te/Mo ratio in the synthesis gel from 0 to 0.17; and heat-treated at 400 or 600ºC in N2 atmosphere), characterized by several physicochemical techniques and tested in the oxidative dehydrogenation (ODH) of ethane. The morphology and microporosity of the catalysts, the nature of V-species on the catalyst surface and the catalytic performance strongly depend on the composition and the heat-treatment temperature. When calcined at 400ºC, the selectivity to ethylene decreases when the amount of tellurium increases, whereas when heat treated at 600ºC, the selectivity to ethylene increases when the Te-loading increases. These trends have been explained on the basis of the good correlation between selectivity to ethylene and the concentration of V4+ species on the surface of catalysts, in which the most selective catalyst is that prepared with a Te/Mo ratio of 0.17 and heat-treated at 600ºC.