物理化学学报 >> 2015, Vol. 31 >> Issue (5): 941-947.doi: 10.3866/PKU.WHXB201503051

催化和表面科学 上一篇    下一篇

二氧化钛负载的镍氧化态对乙腈气相加氢的影响

夏龙飞1, 江治1, 上官文峰1, 顾顺超2,3, 平野真一3   

  1. 1上海交通大学机械与动力工程学院, 上海200240;
    2 上海交通大学化学化工学院, 上海200240;
    3 上海交通大学平野创新研究所, 上海200240
  • 收稿日期:2014-12-09 修回日期:2015-02-09 发布日期:2015-05-08
  • 通讯作者: 上官文峰 E-mail:shangguan@sjtu.edu.cn
  • 基金资助:

    花王株式会社(日本)项目资助

Influence of Oxidation State of Nickel Supported on TiO2 on Gas-Phase Hydrogenation of Acetonitrile

XIA Long-Fei1, JIANG Zhi1, SHANGGUAN Wen-Feng1, GU Shun-Chao2,3, HIRANO Shinichi3   

  1. 1 School of Mechanical Engineering, Shanghai Jiao Tong University, Shanghai 200240, P. R. China;
    2 School of Chemistry and Chemical Engineering, Shanghai Jiao Tong University, Shanghai 200240, P. R. China;
    3 Hirano Institute for Materials Innovation, Shanghai Jiao Tong University, Shanghai 200240, P. R. China
  • Received:2014-12-09 Revised:2015-02-09 Published:2015-05-08
  • Contact: SHANGGUAN Wen-Feng E-mail:shangguan@sjtu.edu.cn
  • Supported by:

    The project was supported by the Project of Kao Corporation (Japan).

摘要:

采用浸渍法制备了二氧化钛负载镍催化剂. 通过控制还原温度(200-400 ℃), 在TiO2上得到不同氧化态的镍颗粒. 结果发现, 乙腈气相加氢反应受镍氧化态的影响, 300 ℃下还原的催化剂表现出最高的乙腈转化活性, 100 ℃时将乙腈完全转化. 产物产率受到Ni/TiO2催化剂酸性的影响, 而催化剂的酸性不仅受到TiO2载体的影响, 还受到负载物Ni 颗粒性质的影响. 随着催化剂还原温度升高, 金属态镍逐渐出现在催化剂表面, 降低了催化剂的酸性强度, 使三乙胺的最大产率升高(从34%升高到48%左右). 研究还发现在Ni/TiO2催化乙腈加氢反应中, 三乙胺是初始产物. Ni 的状态不仅影响乙腈的转化, 还影响产物的脱附. 提出了乙腈加氢的第一步反应机理.

关键词: 乙腈气相加氢, 浸渍法, TiO2, Ni, 胺类化合物

Abstract:

Nickel catalysts supported on TiO2 were prepared using an impregnation method. Changes in the reduction temperature from 200 to 400 ℃ resulted in dispersion of nickel with different oxidation states on TiO2. The gas-phase hydrogenation of acetonitrile was found to be influenced by the nickel oxidation state. Nickel reduced at 300 ℃ gave the highest acetonitrile conversion ratio, i.e., about 100%, when the reaction temperature was 100 ℃. The product yields depend on the amount of acidic sites on Ni/TiO2 catalysts; this can be influenced not only by the TiO2 support, but also by the properties of the supported nickel nanoparticles. The triethylamine yield increased to a maximum (from 34% to about 48%) with increasing reduction temperature; this corresponded to the gradual appearance of Ni0 in Ni/TiO2 and a decrease in the intrinsic acidity of the Ni/TiO2 catalyst. Triethylamine was the initial product in the hydrogenation of acetonitrile with Ni/TiO2. The oxidation state of nickel influenced not only the conversion of acetonitrile but also desorption of the final products. Amechanism for the first step in this reaction is proposed.

Key words: Gas-phase hydrogenation of acetonitrile, Impregnation method, TiO2, Ni, Amine

MSC2000: 

  • O643