催化学报

催化学报 ›› 2007, Vol. 28 ›› Issue (5): 441-445.

• 研究论文 • 上一篇    下一篇

载体对钯催化剂催化苯酚加氢制环己酮性能的影响

朱俊华,丁洁莲,曾崇余   

  1. 南京工业大学化学化工学院, 江苏南京 210009
  • 收稿日期:2007-05-25 出版日期:2007-05-25 发布日期:2011-04-28

Effect of Supports on Catalytic Performance of Palladium Catalysts for Hydrogenation of Phenol to Cyclohexanone

ZHU Junhua, DING Jielian, ZENG Chongyu*   

  1. College of Chemistry and Chemical Engineering, Nanjing University of Technology, Nanjing 210009, Jiangsu, China
  • Received:2007-05-25 Online:2007-05-25 Published:2011-04-28

PDF

1561

被引次数

54

摘要： 分别以MgO,γ-Al2O3和镁铝水滑石(HT)为载体, PdCl2为活性金属前驱体,采用等体积浸渍法制得Pd质量分数为0.5%的Pd/MgO, Pd/Al2O3和Pd/HT催化剂,考察了它们对苯酚加氢制环己酮的催化活性和选择性. 采用X射线衍射、N2吸附、H2程序升温脱附、CO2程序升温脱附和X射线光电子能谱等手段对这些催化剂进行了表征,并与催化活性和选择性关联. 实验结果表明,载体的平均孔径越大,催化剂的表面Pd含量越高,催化剂表面的碱中心越多,则越有利于氢和苯酚在催化剂表面的吸附,从而提高苯酚的转化率和环己酮选择性. 在反应温度为130 ℃, H2与苯酚摩尔比为4, LHSV为0.19 h-1的条件下, 0.5%Pd/HT催化剂上苯酚的转化率可达90%, 环己酮的选择性可达97%以上.

关键词: 苯酚, 加氢, 环己酮, 钯催化剂, 载体, 水滑石

Abstract: The Pd/MgO, Pd/Al2O3, and Pd/HT catalysts with 0.5% Pd contents were prepared by the impregnation method using MgO,γ-Al2O3, and hydrotalcite (HT) as the support, respectively, and PdCl2 as the precursor. Catalytic performance of the catalysts for hydrogenation of phenol to cyclohexanone was evaluated in a fixed-bed reactor. These catalysts were characterized byX-raydiffraction, N2 adsorption, H2 temperature-programmed desorption, CO2 temperature-programmed desorption, andX-rayphotoelectron spectroscopy. The results showed that bigger average pore diameter, higher surface Pd content, and more surface base sites were favorable for the adsorption of hydrogen and phenol and consequently increased the conversion of phenol and the selectivity for cyclohexanone. Under the conditions of 130 ℃, H2∶phenol molar ratio = 4∶1, and LHSV=0.19 h-1, the conversion of phenol was 90% and the selectivity for cyclohexanone reached 97% over the 0.5%Pd/HT catalyst.

Key words: phenol, hydrogenation, cyclohexanone, palladium, support, hydrotalcite