Bi添加对MoVO/AlPO4催化剂异丁烯选择氧化反应性能的影响

采用溶胶-凝胶法制备了MoVO/AIPO4和MoVBiO/AIPO4催化剂,运用X射线衍射、激光拉曼光谱、X光电子能谱、程序升温还原对催化剂进行了表征,考察了Bi的添加对催化剂结构及其催化异丁烯选择氧化制甲基丙烯醛(MAL)反应性能的影响.结果表明,适量Bi的引入可显著提高MoVO-AIPO4上异丁烯选择氧化反应性能,...

Effects of Bi on the Catalytic Performance of MoVO/AIPO4 Catalyst for Selective Oxidation of Isobutene

MoVO/AlPO4 and MoVBiO/AlPO4 catalysts have been prepared by the sol-gel method.The effects of Bi on surface acidity,distribution of active species,V5+/V4+ ratio,crystalline phase,and catalytic performance for selective oxidation of isobutene to methacrolein were investigated.The catalysts were characterized by X-ray diffraction,FT-Raman spectroscopy,temperature programmed reduction and X-ray photoelectron spectroscopy.The results showed that the addition of Bi at a proper amount obviously improves the catalytic performance of catalyst for selective oxidation of isobutene.Methacrolein selectivity is elevated from 29.1% to 75.2% with the increase of Bi/V ratio from 0 to 0.5.The surface acidity,crystalline phase,and dispersion of molybdenum and vanadium oxides species are responsible for the catalytic properties of the MoVBiO/AlPO4 catalyst,which are especially related to the V5+/V4+ ratio on the surface.