摘要
采用溶胶-凝胶法制备了MoVO/AlPO4和MoVBiO/AlPO4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-AlPO4上异丁烯选择氧化反应性能,MAL选择性由29.1%提高至75.2%.这与Bi的加入降低了催化剂表面强酸位数量,促进了Mo氧化物和V氧化物的分散和提高了催化剂表面V5+/V4+比例有关.
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.
出处
《催化学报》
SCIE
CAS
CSCD
北大核心
2011年第2期352-356,共5页
基金
国家自然科学基金(20806059)
关键词
溶胶-凝胶法
异丁烯
选择氧化
甲基丙烯醛
钼
钒
铋
磷酸铝
sol-gel method
iso-butene
selective oxidation
methacrolein
molybdenum
vanadium
bismuth
aluminum phosphate
