催化学报

催化学报 ›› 2008, Vol. 29 ›› Issue (8): 720-726.

• 研究论文 • 上一篇    下一篇

发烟硫酸中Pd/C催化甲烷选择氧化制甲醇

魏新,叶林敏,祝明霞,袁友珠   

  1. 厦门大学化学化工学院化学系, 固体表面物理化学国家重点实验室, 福建厦门 361005
  • 收稿日期:2008-08-25 出版日期:2008-08-25 发布日期:2012-06-20

Selective Oxidation of Methane to Methanol in Oleum over Pd/C Catalyst

WEI Xin, YE Linmin, ZHU Mingxia, YUAN Youzhu*   

  1. State Key Laboratory of Physical Chemistry of Solid Surfaces, Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, Fujian, China
  • Received:2008-08-25 Online:2008-08-25 Published:2012-06-20

PDF

1098

被引次数

55

摘要： 以PdCl2为前驱体,采用浸渍法制备了Pd/C催化剂,并在发烟硫酸中考察了其催化甲烷选择氧化反应的性能,采用X射线粉末衍射、X射线光电子能谱、高分辨透射电镜和CO吸附等方法对催化剂进行了表征. 甲烷选择氧化反应得到的主产物硫酸单甲酯经水解后得到甲醇,在5%Pd/C催化剂、Pd用量30 μmol、反应温度180 ℃、反应压力4.0 MPa、反应时间4 h和发烟硫酸中SO3含量为50%的优化工艺条件下,甲烷转化率为23.6%, 甲醇的选择性和收率分别为69.5%和16.4%, 在一定程度上可实现催化剂的多次重复使用. Pd/C催化剂上的甲烷选择氧化反应可能遵循亲电取代机理,催化性能与Pd负载量、Pd粒子尺寸和分散度等有关.

关键词: 钯, 活性炭, 负载型催化剂, 甲烷, 选择氧化, 甲醇, 发烟硫酸

Abstract: The selective oxidation of methane to methanol over Pd/C catalysts generated from a PdCl2 precursor was investigated in oleum. Characterization of the catalysts was performed byX-raydiffraction,X-rayphotoelectron spectroscopy, high-resolution transmission electron microscopy, and CO adsorption. The major product in the oxidation reaction was methyl bisulfate, which was then hydrolyzed into methanol. Methane conversion of 23.6% with methanol selectivity of 69.5% and yield of 16.4% was achieved under the optimum conditions of 5%Pd/C, 30 μmol Pd, reaction temperature 180 ℃, methane pressure 4.0 MPa, reaction time4 h, and 50% sulfur trioxide concentration. After facile separation with the reactants and pretreatment, the catalyst could be reused several times with considerable stability. The selective oxidation of methane catalyzed by Pd/C catalysts in oleum possibly involved an electrophilic substitute mechanism. The catalytic performance was related to the Pd loading, dispersion, and particle size.

Key words: palladium, activated carbon, supported catalyst, methane, selective oxidation, methanol, oleum