物理化学学报 >> 1992, Vol. 8 >> Issue (04): 470-475.doi: 10.3866/PKU.WHXB19920409

研究论文 上一篇    下一篇

硫物种对负载型钯催化剂上氢吸附性质的影响

肖天存; 安立敦; 张兵; 蒋致诚   

  1. 中国科学院兰州化学物理研究所,兰州 730000
  • 收稿日期:1991-02-14 修回日期:1991-09-25 发布日期:1992-08-15
  • 通讯作者: 安立敦

Effect of Sulfur Species on H2 Adsorption on Supported Palladium Catalyst

Xiao Tian-Cun; An Li-Dun; Zhang bing; Jiang Zhi-Cheng   

  1. Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000
  • Received:1991-02-14 Revised:1991-09-25 Published:1992-08-15
  • Contact: An Li-Dun

摘要: 用X光光电子能谱(XPS)分析了负载型Pd/Al_2O_3催化剂上硫和钯的状态。以程序升温脱附-质谱(TPD-MS)方法研究了不同硫物种及不同气氛对催化剂氢吸附性质的影响。结果表明: 硫物种对氢吸附的影响按S_2~(2-)、S~(2-)、SO_4~(2-)的顺序减小, 且前两者的影响远比SO_4~(2-)的大。这与催化剂在H_2-O_2反应中的抗硫性评价结果一致。并用原子分子轨道理论对上述结果进行了讨论。

关键词: 负载型Pd/Al2O3催化剂, 硫物种, H2吸附, αβ1β2吸附态的氢

Abstract: A series of supported palladium catalysts were prepared with impregnating method. SO_4~(2-) was introduced by dipping Al_2O_3 into dilute H_2SO_4 solution for the preparation of Pd/Al_2O_3--SO_4 or impregnating Pd/Al_2O_3 with a series of K_2SO_4 solutions for Pd/SO_4~(2-)/Al_2O_3 as catalysts. X-ray photoelectron spectroscopy was employed to measure the states of sulfur and palladium before and after the catalysts were treated under different atmospheres. Temperature programmed desorption-mass spectroscopy (TPD-MS) was used to investigate the effect of different sulfur species and atmosphere on H_2 adsorption on the catalysts. The results showed as follows: The influence of sulfur species upon H_2 desorption declined in a order as S_2~(2-), S~(2-) and SO_4~(2-), and the effect of the former two was more distinct than SO_4~(2-). Their behaviors were in accord with the evaluation of the catalyst for H_2-O_2 reaction, which may be interpreted with the molecular orbital theory.

Key words: Pd/Al2O3 catalysts, Sulfur species, H2 adsorption, αβ1 and β2 adsorbed hydrogen