Preparation of V-Al-O catalysts by hydrothermal route and their isobutane dehydrogenation performance

High activity vanadia-based catalysts for isobutane dehydrogenation have been prepared by hydrothermal method.The structure and properties of catalysts were characterized by XRD,H2-TPR,RAMAN,BET and XPS.It was found that the structure of vanadium oxide on surface of catalyst convert from isolated monomeric vanadia species to polymeric vanadia species with increasing of vanadia content.Catalytic test shows that isolated vanadia has higher catalytic activity for isobutane dehydrogenation than polymeric vanadia.The catalyst with 16% vanadia content has higher catalytic activity.The isobutane conversion and isobutene selectivity achieve 55% and 85%,respectively.Whether or not,all catalysts prepared by hydrothermal method have high stability for isobutane dehydrogenation to isobutene.