催化学报

催化学报 ›› 2013, Vol. 34 ›› Issue (2): 341-350.DOI: 10.1016/S1872-2067(11)60487-7

• 研究论文 • 上一篇    下一篇

Cu 掺杂对介孔 VOx-TiO2 催化苯羟基化制苯酚的影响

徐丹1, 贾丽华1,a, 郭祥峰2,b   

  1. 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
  • 收稿日期:2012-09-27 修回日期:2012-11-07 出版日期:2013-02-05 发布日期:2013-02-05

Cu-doped mesoporous VOx-TiO2 in catalytic hydroxylation of benzene to phenol

XU Dan1, JIA Lihua1,a, GUO Xiangfeng2,b   

  1. 1College of Chemistry and Chemical Engineering, Qiqihar University, Qiqihar 161006, Heilongjiang, China; 2Key Laboratory of Fine Chemicals, College of Heilongjiang Province, Qiqihar University, Qiqihar 161006, Heilongjiang, China
  • Received:2012-09-27 Revised:2012-11-07 Online:2013-02-05 Published:2013-02-05

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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.

关键词: 铜, 钒物种, 介孔二氧化钛, 苯, 羟基化, 苯酚

Abstract: 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, H2 temperature-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 structure as 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.

Key words: copper, vanadium species, mesoporous titania, benzene, hydroxylation, phenol