催化学报

催化学报 ›› 2011, Vol. 32 ›› Issue (2): 315-320.DOI: 10.3724/SP.J.1088.2011.00934

• 研究论文 • 上一篇    下一篇

柠檬酸改性对掺 Ba 纳米 MgO 及其担载的 Ru 氨合成催化剂性能的影响

霍超, 夏庆华, 潘美华, 杨霞珍, 骆燕, 刘化章   

  1. 浙江工业大学化学工程与材料学院, 浙江杭州 310032
  • 收稿日期:2010-10-04 修回日期:2010-11-02 出版日期:2011-01-26 发布日期:2014-06-25

Effects of Citric Acid-modification on the Performance of Nano-Ba-MgO Sup-port and Its Ru-Based Catalysts for Ammonia Synthesis

HUO Chao*, XIA Qinhua, PAN Meihua, YANG Xiazhen, LUO Yan, LIU Huazhang   

  1. College of Chemical Engineering and Materials Science, Zhejiang University of Technology, Hangzhou 310032, Zhejiang, China
  • Received:2010-10-04 Revised:2010-11-02 Online:2011-01-26 Published:2014-06-25

PDF

995

被引次数

8

摘要： 采用超声-静电吸附法制备了一系列经柠檬酸改性的掺 Ba 纳米 MgO 及其负载的氨合成 Ru 催化剂. 并采用场发射扫描电镜、X 射线粉末衍射、N2 物理吸附-脱附、电感耦合等离子体发射光谱及红外光谱等手段对样品进行了表征. 结果表明, 适量添加柠檬酸可有效调控 Ba 的掺杂量, 从而使 Ba-MgO 结构与化学性质发生变化, 其表面性能得到极大改善, 最终导致相应 Ru/Ba-MgO 催化剂氨合成的低温活性显著提高. 在 10 MPa, 400 ?C, 10 000 h?1 的条件下, 柠檬酸浓度为 2.0 mmol/L 时制得的 Ru/Ba-MgO 催化剂出口氨生成速率达 63.2 mmol/(g•h), 较未经柠檬酸改性的 Ru/Ba-MgO 催化剂活性提高了 21%.

关键词: 柠檬酸, 改性, 掺钡, 纳米氧化镁, 钌, 氨合成, 超声制备

Abstract: A series of citric acid-modified Ba-MgO supports (Ba-MgO(CA)) were prepared by ultrasound electrostatic adsorption (UEA), and the corresponding Ru catalysts for ammonia synthesis were then prepared by the impregnation method. Their physical and chemical properties were characterized by scanning electronic microscopy, X-ray diffraction, nitrogen physical adsorption, inductively coupled plasma-atomic emission spectrometry, and infrared spectroscopy. The results showed that the introduction of citric acid during the preparation of the support changed not only the chemical and textural properties of the nano-Ba-MgO support but also the doping amount of Ba in the Ba-MgO(CA) support. When the concentration of citric acid was 2.0 mmol/L, the Ru/Ba-MgO(CA) catalyst exhibited the highest catalytic activity for ammonia synthesis with a reaction rate of 63.20 mmol/(g·h) at 400 oC, 10 MPa, and 10 000 h-1, which is 21% higher than that of unmodified Ru/Ba-MgO.

Key words: citric acid, modification, barium doping, nano-magnesia, ruthenium, ammonia synthesis, ultrasonic preparation