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 600°C in N 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 400°C, the selectivity to ethylene decreases when the amount of tellurium increases, whereas when heat treated at 600°C, 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 V 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 600°C.

The authors would like to thank the Spanish Ministry of Economy and Competitiveness for funding the projects (MINECO/FEDER): CRTl2018-099668-B-C21, PID2019-106662RBC44, MAT2017-84118-C2-1-R and SEV-2016-0683. A.A. acknowledges Severo Ochoa Excellence Program for his fellowship (BES-2017-080329). Authors would also like to acknowledge the “A-Team” of the ITQ (Dr. Miguel Palomino, Dr. Susana Valencia and Prof. Fernando Rey) for their assistance in the performance of the adsorption experiments.