Cu掺杂对介孔VO_x-TiO_2催化苯羟基化制苯酚的影响  

Cu-dopedmesoporous VO_x-TiO_2 incatalytic hydroxylation of benzene to phenol

作　　者：徐丹[1] 贾丽华[1] 郭祥峰 

机构地区：[1]齐齐哈尔大学化学与化学工程学院,黑龙江齐齐哈尔161006 [2]黑龙江省普通高校精细化工重点实验室,黑龙江齐齐哈尔161006

出　　处：《催化学报》2013年第2期341-350,共10页

基　　金：国家自然科学基金(21176125);黑龙江省教育厅科研项目(2012TD012;12511Z030;12521594);黑龙江省研究生创新项目(YJSCX2011-198HL)~~

摘　　要：将Cu作为第二金属,制备了不同Cu掺杂量的和不同温度下焙烧的双金属改性的Cu/VOx-TiO2复合催化剂,并用于液相苯直接羟基化制苯酚反应中.固定钒的含量为4.3%,合成了一系列不同Cu掺杂量(w=0.29%~2.5%)的催化剂,并在不同的温度下(350~650°C)进行了焙烧.利用X射线衍射、N2吸附-脱附、扫描电镜、透射电镜、H2程序升温还原以及X射线光电子能谱对催化剂进行了表征.结果表明,加入Cu后催化剂仍保持有序的介孔结构,并且有效地促进了VOx物种在载体TiO2上的分散和VOx物种的还原,同时提高了催化剂的热稳定性,其中Cu以+2价的形态存在于催化剂中.另外,考察了催化剂用量,反应温度等对苯羟基化反应性能的影响.Liquid phase hydroxylation of benzene to phenol with hydrogen peroxide over VOx-TiO2 catalyst samples with Cu as a second metal was investigated. A series of Cu/VOx-TiO2 (vanadium loading was 4.3%) catalysts were prepared within the range of Cu loading (0.29%–2.5%) and calcined at the temperatures of 350–650 °C. The catalyst samples were characterized by N2 adsorption-desorption, scanning electron microscopy, H2temperature-programmed reduction, X-ray diffraction, transmission electron microscopy, and X-ray photoelectron spectroscopy. After the addition of Cu, the Cu/VOx-TiO2 catalyst had more ordered mesoporous structureas compared with the VOx-TiO2 catalyst, and the vanadium was monodispersed on the TiO2 support. The presence of Cu2+ ions on the catalyst surface was shown by XPS measurements. These Cu2+ ions probably contributed to the dispersion of vanadium on the surface of the TiO2 support, and the more facile reduction of VOx. The Cu2+ ions also strengthened the thermostability of the Cu/VOx-TiO2 catalyst. The effects of some other variables (Cu loading, catalyst amount, and reaction temperature) on the catalytic performance were also investigated.

关 键 词：铜 钒物种 介孔二氧化钛 苯 羟基化 苯酚 

分 类 号：O643.32[理学—物理化学] O625.312[理学—化学]