水热法制备V-Al-O催化剂及其异丁烷脱氢性能

以水热法制备了具有高活性与稳定性的异丁烷脱氢V-Al-O催化剂,采用XRD、H2-TPR、RA-MAN和XPS等方法对催化剂的结构和性质进行了表征。研究表明,随着钒含量的增加,表面钒物种由高分散孤立状态向聚合态及晶态转变。异丁烷催化脱氢活性测试显示,催化剂表面孤立的、高分散的钒物种具有更高的脱氢活性,而表面聚合度高的钒物种则表现出更好的选择性。当催化剂钒质量分数为16%时,获得的催化剂脱氢活性最高,其异丁烷转化率达55%,异丁烯选择性超过85%。水热法制备的催化剂对异丁烷脱氢均具有一定的稳定性.

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.