The introduction of cerium oxide to phase-pure M1 MoVNbTeo(x) with CeO2 loading from 0 up to 90 wt.% results in highly active catalysts for oxidative dehydrogenation of ethane (ODHE). These catalysts are characterized with BET, ICP, XRD, TEM, SEM and XPS techniques and tested for ODHE process. The results show that the increase of active site, V5+, is one of the dominant factors to improve the ethane conversion. In addition, the easier re-oxidation of V4+ to V5+ due to the presence of Ce4+ makes an extra contribution to the increase of turn-over frequency. Among all the catalysts, M1 catalyst with 30 wt.% CeO2 loading obtains the best productivity of 0.69 kg(C2H4/)kg(cat).h while the corresponding performance of phase-pure M1 catalyst is 0.34 kg(C2H4)/kg(cat).h at 400 degrees C with the contact time of 18.52 g(cat).h/mol(C2H6). It is further demonstrated that M1/CeO2 catalyst (e.g., with 50 wt.% CeO2 as a representative) loading remains highly active after 3 cycles of refreshment in situ, and its crystal structure and surface morphology keep stable compared to the fresh catalyst. (C) 2018 Elsevier Inc. All rights reserved.