Yb_2O_3对Bi_2O_3-MoO_3催化剂性能的影响  

Promotion Effects of Ytterbium on the Bi_2O_3-MoO_3 Catalyst

作　　者：李铭岫[1] 韩占刚[1] 杨述韬[1] 

机构地区：[1]河北师范大学化学学院,河北石家庄050091

出　　处：《分子催化》2003年第6期439-443,共5页Journal of Molecular Catalysis(China)

基　　金：河北省科学技术厅(No:002130103D);河北省自然科学基金(No:200151)资助项目.

摘　　要：在Bi2O3-MoO3复合氧化物催化剂中加入Yb2O3,可明显提高异丁烯转化率和生成甲基丙烯醛的选择性.用XRD、FT-Raman光谱和SEM技术研究了催化剂的组成和性质.Bi2O3-MoO3催化剂的成分主要是α-Bi2Mo3O12,添加镱后出现了Yb2Mo3O12的吸收峰;且Bi2O3-MoO3-Yb2O3催化剂的FT-Raman光谱图在363cm-1处出现了Yb-O伸缩振动峰,同时Bi2O3-MoO3催化剂的钼-氧振动发生红移,表明镱的加入使钼-氧键的振动减弱,使Bi2O3-MoO3-Yb2O3催化剂有较高传递晶格氧给予异丁烯的能力,导致异丁烯转化率和生成甲基丙烯醛的选择性均显著提高.The addition of ytterbium oxide to Bi_2O_3-MoO_3 catalyst enhanced conversion of isobutene and selection to methacrolein . Composition and properties of catalysts were characterized by XRD, FT-Raman spectra and SEM techniques. X-ray diffraction analyses of samples exhibit that α- Bi_2Mo_3O_(12) is the major component of the Bi_2O_3-MoO_3 catalyst and XRD pattern of Yb_2Mo_3O_(12) appears in ytterbium doped catalyst . The FT-Raman spectra of Bi_2O_3-MoO_3-Yb_2O_3 catalyst show that the band at 363 cm^(-1) is due to the stretching vibration of the Yb-O bond , and the vibration of Mo-O bond shifts to lower frequency. The results revel the Bi_2O_3-MoO_3-Yb_2O_3 catalyst has higher ability of transmit lattice oxygen to isobutene. That leads to improve the conversion of isobutene and selection to methacrolein .

关 键 词：镱 Bi2O3-MoO3催化剂 异丁烯 甲基丙烯醛 选择氧化 

分 类 号：O643.32[理学—物理化学]