Sm对MoO_3-Bi_2O_3催化剂性能的影响

Effect of Sm on catalytic performance of MoO_3-Bi_2O_3 catalysts

在MoO3-B i2O3催化剂中加入稀土氧化物Sm2O3,在固定床反应器中考查了Sm2O3添加量、反应温度、异丁烯浓度、原料气流量等对异丁烯转化为甲基丙烯醛反应的影响。实验表明,添加Sm2O3可明显提高异丁烯的转化率和甲基丙烯醛的选择性。用XRD技术研究了催化剂的组成,Mo-B i-O催化剂的成分主要是B i2O3和MoO3的混合物,添加Sm后出现了Sm2Mo3O12的衍射峰,且衍射峰的强度随着Sm添加量的增加而增强。

The samarium oxide was added to MoO3 -Bi2O3 6atalyst. The reaction temperature, concentration of isobutene in the reactant gases and Sm2O3proportion in the MoO3 -Bi2O3 catalysts were studied in the fixed bed reactor. The results showed that the conversion of isobutene and selectivity for methacrolein were improved hy adding samariumoxlde. The maximum yield of methacrolein was obtained when the proportion of samarium reached 15%. XRD patterns of samples revealed the a-Bi2MoO12 was the major structure of the Mo - Bi - O catalyst. XRD pattems-of Sm：Mo3O12 appeared in samarium doped catalyst and intensity of patterns were stronger with the increase of samarium content.