担载钒氧化物催化剂对丙烷选择氧化性能  

Selective Oxidation Performance of Propane over Supported Vanadium Oxide Catalysts

作　　者：刘坚[1] 赵震[1] 王宏宣[1] 段爱军[1] 姜桂元[1] 

机构地区：[1]中国石油大学重质油国家重点实验室,北京102249

出　　处：《物理化学学报》2011年第11期2659-2664,共6页Acta Physico-Chimica Sinica

基　　金：新世纪优秀人才支持计划(NCET-10-0811);高等学校博士点基金(200804251016);国家自然科学基金(20803093;20833011);国家高技术研究发展计划(863)(2006AA06Z313);中石油项目及创新基金(2010D-4604-0402)资助项目~~

摘　　要：用等体积浸渍法制备了SBA-15担载的钒基氧化物催化剂,使用X射线衍射(XRD)分析、氮气吸附、紫外激光拉曼、傅里叶变换红外(FTIR)光谱和紫外-可见漫反射(UV-Vis DRS)光谱对催化剂的结构进行了表征,并评价了催化剂对丙烷选择氧化的活性与选择性.实验结果表明SBA-15载体对丙烷选择氧化的活性优于常规的SiO_2载体.SBA-15担载的低载量催化剂是高分散的催化剂体系,在低钒载量(n(V)/n(Si)<2.5%)时,催化剂具有规则的六方介孔结构.低钒载量(n(V)/n(Si)<0.1%)时,隔离四配位的钒氧化物是丙烷选择氧化生成醛类化合物的活性物种;高钒载量(n(V)/n(Si)>2.5%)时,聚合六配位的钒氧化物和微晶钒氧化物是丙烷脱氢或深度氧化的活性物种.A series of SBA-15 supported vanadium oxide catalysts with different active components were prepared by the method of incipient-wet impregnation.The structures of the catalysts were characterized by N_2 adsorption,X-ray diffraction（XRD）,ultraviolet（UV）-Raman,Fourier transform infrared（FTIR）,and ultraviolet-visble diffuse reflectance spectroscopy（UV-Vis DRS） techniques,and their catalytic performances for the selective oxidation of propane were investigated.The results showed that SBA-15 was a better support in the catalyst system than SiO_2 for the selective oxidation of propane to aldehydes.The SBA-15 supported low loading catalyst is a highly dispersed catalyst system and the SBA-15 supported vanadium oxide samples with low loading（n（V）/n（Si）2.5%） have ordered hexagonal mesostructures.For the VO_x/SBA-15 catalysts,isolated vanadyl species with tetrahedral coordination are the active sites for aldehyde formation at very low loadings of vanadium（n（V）/n（Si）0.1%）.The polymeric vanadyl species with octahedral coordination and microcrystalline vanadium oxide are active sites for the oxidative dehydrogenation or deep oxidation of propane when the loading of vanadium（n（V）/n（Si）） is higher than 2.5%.

关 键 词：丙烷选择氧化 催化剂 SBA-15介孔分子筛 担载钒氧化物 表征 

分 类 号：TQ203.2[化学工程—有机化工]