催化学报 ›› 2012, Vol. 33 ›› Issue (8): 1374-1382.DOI: 10.3724/SP.J.1088.2012.20324

• 研究论文 • 上一篇    下一篇

二硝基甲苯低压加氢 Ni-La-B 非晶态合金催化剂的制备及结构表征

闫少伟1,2, 范辉2, 梁川1, 李忠1,*, 于智慧1   

  1. 1太原理工大学煤科学与技术教育部和山西省重点实验室, 山西太原 030024; 2赛鼎工程有限公司技术中心, 山西太原 030024
  • 收稿日期:2012-03-13 修回日期:2012-05-10 出版日期:2012-08-01 发布日期:2012-08-01

Preparation and Characterization of Ni-La-B Amorphous Alloy Catalyst for Low-Pressure Dinitrotoluene Hydrogenation

YAN Shaowei1,2, FAN Hui2, LIANG Chuan1, LI Zhong1,*, YU Zhihui1   

  1. 1Key Laboratory of Coal Science and Technology, Ministry of Education and Shanxi Province, Taiyuan University of Technology, Taiyuan 030024, Shanxi, China; 2Center of Technology, Sedin Engineering Company Limited, Taiyuan 030024, Shanxi, China
  • Received:2012-03-13 Revised:2012-05-10 Online:2012-08-01 Published:2012-08-01

摘要: 用化学还原法制备了 Ni-La-B 非晶态合金催化剂, 并采用 X 射线衍射、透射电镜、差热分析、X 射线光电子能谱、电感耦合等离子光谱和 H2 程序升温脱附技术对催化剂进行了表征, 研究了 La 含量对催化剂微观结构及其催化二硝基甲苯 (DNT) 加氢制二氨基甲苯 (DAT) 性能的影响. 结果表明, 随着助剂 La 含量的增加, Ni-La-B 催化剂中非晶态结构的无序程度增大, 催化剂平均粒径逐渐由 70 nm 左右减小至 10 nm 左右, 分布更加均匀; 同时降低了 Ni 吸附 H2 的强度, 使 H2 吸附物种更易于在催化剂表面流动并参与反应. 另外, La 助剂还显著提高了催化剂的热稳定性和抗氧化性. 在二硝基甲苯加氢反应中, 催化剂性能随着 La 加入量提高至 6% (摩尔分数) 时, 1 MPa 低压条件下 DNT 转化率和 DAT 选择性均达 100%. 当 La 加入量为 8% 时, 催化剂的 Ni 活性中心数明显减少, 其活性下降.

关键词: 二硝基甲苯, 甲苯二胺, 非晶态合金, 镍基催化剂, 镧助剂

Abstract: Ni-La-B amorphous alloy catalyst was prepared by KBH4 reduction for liquid phase hydrogenation of dinitrotoluene (DNT) to diaminotoluene (DAT). The effect of La content on microstructure and catalytic performance of Ni-La-B amorphous alloy catalyst for DNT hydrogenation was investigated. The catalyst was characterized by X-ray diffraction, transmission electron microscopy, differential scanning calorimetry, X-ray photoelectron spectroscopy, inductively coupled plasma emission spectroscopy, and H2 temperature-programmed desorption. The results showed that the addition of La could enhance the degree of long-range disorder, reduce the particle diameter from 70 to 10 nm, weaken the strength of Ni–H bond, and improve the thermal stability and antioxidation. The increasing of La addition from 0 to 6% (molar fraction) led to the enhancement of catalytic performance. When the addition of La was 0.6%, Ni-La-B catalyst exhibited the highest performance for low-pressure (1 MPa) DNT hydrogenation, the conversion of DNT and selectivity for DAT reached 100%. Further increasing of La addition from 6% to 8% led to decrease of the surface Ni content and the catalytic activity obviously.

Key words: dinitrotoluene, diaminotoluene, amorphous alloy, nikel-based catalyst, lanthanum modification