铋钼复合氧化物催化剂的结构及其对丙烷选择氧化反应的催化性能  

Structure and Catalytic Properties of Bi-Mo Composite Oxide Catalyst for Selective Oxidation of Propane

作　　者：杨汉培[1] 范以宁[1] 林明[1] 许波连[1] 陈懿[1] 

机构地区：[1]南京大学化学系介观材料科学实验室,南京210093

出　　处：《催化学报》2001年第6期515-519,共5页

基　　金：国家重点基础研究发展规划项目 (G19990 2 2 40 0 );南京大学分析测试基金项目资助课题

摘　　要：应用X射线衍射 (XRD) ,傅里叶变换激光拉曼光谱 (FT LRS)和微型催化反应装置等测试手段研究了丙烷选择氧化的Bi Mo复合氧化物催化剂的结构和催化性能 .结果表明 ,Bi组分是丙烷催化氧化脱氢为丙烯的主要活性组分 ,而丙烯醛选择性的大小与Bi Mo复合氧化物催化剂的组成和结构密切相关 .不同组成的Bi Mo复合氧化物催化剂在丙烷转化率 (～ 2 8 0 % )相近的情况下 ,其丙烯醛选择性随Mo/ (Mo +Bi)原子比的增加先逐渐增加 ,在Mo/ (Mo +Bi)原子比为 0 5 0时达极大值 (～ 2 8 1% ) .随Mo/ (Mo +Bi)原子比进一步增加 ,丙烯醛选择性又急剧下降 .XRD和FT LRS结果表明 ,Bi2 O3 和MoO3 之间可形成二元Bi Mo O晶相固溶体 ,从而显著提高了催化剂对选择氧化反应的催化性能 .尤其是当α Bi2 (MoO4 ) 3 和γ Bi2 MoO6两相共存时 ,Bi Mo复合氧化物催化剂具有较优良的选择氧化催化性能 .γ Bi2 MoO6参与了α Bi2 (MoO4 ) 3 对丙烷的选择氧化 。The structure and catalytic properties of the Bi Mo composite oxide catalyst with different compositions for the selective oxidation of propane have been studied by using XRD, FT LRS and microreactor tests. It has been shown that bismuth is the main active component for the catalytic oxydehydrogenation of propane to propylene, and propylene is the most probable intermediate species for the selective oxidation of propane to acrolein. With the decrease of bismuth content in the composite oxide, the propylene selectivity decreases gradually while the acrolein selectivity first increases and then decreases remarkably. At the same propane conversion (～28 0%), the acrolein selectivity reaches the highest value (～28 1%) when the compositon is 0 50 (Mo/(Mo+Bi) atomic ratio). The XRD and FT LRS results have revealed that Bi 2O 3 and MoO 3 form crystalline γ Bi 2MoO 3 and α Bi 2(MoO 4) 3, which can promote the formation of acrolein. It is proposed that α Bi 2(MoO 4) 3 is the main active component for the selective oxidation of propane to acrolein and γ Bi 2MoO 3 may participate in the regeneration of lattice oxygen ions in α Bi 2(MoO 4) 3, which enhances the catalytic activity of α Bi 2(MoO 4) 3 for the selective oxidation of propane to acrolein.

关 键 词：氧化铋 氧化钼 丙烷 选择氧化 丙烯醛 复合氧化物催化剂 催化性能 结构 

分 类 号：O643.3[理学—物理化学]