MoO_3/γ-Al_2O_3催化剂上正丁烷催化脱氢制正丁烯  

n-Butane Catalytic Dehydrogenation to n-Butene on MoO_3/γ-Al_2O_3 Catalysts

作　　者：刘志军[1] 陆江银[1] 

机构地区：[1]新疆大学石油天然气精细化工教育部重点实验室,乌鲁木齐830046

出　　处：《化工生产与技术》2009年第2期20-23,共4页Chemical Production and Technology

基　　金：新疆大学博士科研启动基金(BS060101)

摘　　要：使用浸渍法制备了不同负载量的MoO3/γ-Al2O3催化剂,考察了它们在550℃反应温度下正丁烷催化脱氢性能,用XRD,FT-IR和Raman光谱对催化剂的表面结构进行了研究,并分析了催化剂的表面结构与其催化性能的关系。结果表明,γ-Al2O3载体表面钼氧物种随负载量的增加变化情况为:孤立MoO3四面体-二维多聚MoO3八面体-MoO3晶体和Al3(MoO3)3晶体,MoO3在载体表面的最大单层覆盖的质量分数约为20%;孤立分散MoO4物种对正丁烯的选择性比二维多聚MoO6物种及三维的MoO3要高,负载的质量分数5%催化剂取得最高的正丁烯选择性为62.54%;15%～35%催化剂取得较好的正丁烯收率,在11.0%～11.7%,差距不大;MoO3多层聚集态(负载的质量分数为35%)的催化剂相比单层覆盖态(20%),催化活性没有因为钼氧物种的聚集而有大的降低,正丁烯收率仅少0.08%。MoO3/γ-Al2O3 catalysts of different loadings were prepared by the impregnation method and their dehydrogenation of n- butane at 550 ℃ was reviewed. The surface composition of catalysts was characterized by XRD, FT-IR and Raman techniques, and the relationship of surface composition of catalysts with the catalytic property was analysed. The results indicated that the surface molybdenum oxide species on γ -Al2O3 are primarily isolated, tetrahedrally coordinated at low loadings, tend toward polymerized, octahedrally coordinated at high loadings and tend toward crystalline MoO3 and Al2 (MoO4)3 at exceeding monolayer coverage. The highest MoO3 proportion of monolayer coverage was about 20wt.%. The n-butene selectivity of the isolated MoO4 species was higher than that of the polymerized MoO6 and crystalline MoO3 and Al2 (MoO4)3 species. The highest n-butene selectivity attained by the 5% catalyst was 62.54%. The catalysts of the 15%～35% loadings attained the preferable yield of n-butene that was 11.0%～11.7%. The catalytic activity of the catalysts with multilayer coverage (35% loadings) didn't reduce significantly owing to the polymerization of the molybdenum oxide species comparing with the catalysts with monolayer coverage (20% loadings) and the n-butene yield was only 0.08% lower than that of the latter.

关 键 词：MoO3/γ-Al2O3催化剂 正丁烷 催化脱氢 正丁烯 

分 类 号：TQ221.213[化学工程—有机化工]