催化学报

催化学报 ›› 2006, Vol. 27 ›› Issue (10): 911-915.

• 研究论文 • 上一篇    下一篇

α-Al2O3的性质对负载钯催化剂催化CO偶联反应的影响

林茜,赵秀阁,毕伟,肖文德   

  1. 华东理工大学联合化学反应工程研究所, 上海 200237
  • 收稿日期:2006-10-25 出版日期:2006-10-25 发布日期:2010-11-28

Influence of α-Al2O3 Properties on CO Catalytic Coupling Reaction over Pd Catalyst

LIN Qian, ZHAO Xiuge, BI Wei, XIAO Wende*   

  1. UNILAB, State Key Laboratory of Chemical Reaction Engineering, East China University of Science and Technology, Shanghai 200237, China
  • Received:2006-10-25 Online:2006-10-25 Published:2010-11-28

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摘要： 以不同来源的 α-Al2O3 为载体制备了用于催化CO偶联制草酸二甲酯反应的Pd/α-Al2O3 催化剂,利用X射线衍射、 N2吸附和X射线能谱等手段对载体进行了表征. 结果表明,催化剂活性与载体的比表面积没有必然联系,但依赖于载体孔容及孔径的分布范围. 同时 α-Al2O3 的纯度和杂质种类对催化剂活性也有影响,少量钠氧化物和 γ-Al2O3 的存在会大大降低催化剂的活性. 此外,利用CO化学吸附法分析了催化剂活性组分的分布情况. 结果表明,催化剂表面活性金属Pd的分散度达到3.94%以上时,分散度的进一步增大对CO偶联反应没有明显影响.

关键词: 一氧化碳, 偶联, 亚硝酸甲酯, 草酸二甲酯, 钯, 氧化铝, 载体, 负载型催化剂

Abstract: A series of Pd/α-Al2O3 catalysts for the CO coupling reaction were prepared with α-Al2O3 from five different sources. The influence of impurities, specific surface area, and pore structure of the support on the catalyst activity was studied. X-ray diffraction and energy dispersive X-ray analysis results confirm the existence of various impurities in three α-Al2O3 samples due to their different production methods. The sodium oxides and γ-Al2O3 in the support decrease the catalyst activity from 45%CO conversion to 10%. The N2 adsorption result shows that the specific surface area and pore volume of the support are not as much important as the pore distribution for the activity of Pd/α-Al2O3, and the double pore structure of the support is necessary for preparing high activity catalysts. Moreover, the results of CO chemical adsorption on the five catalysts show that the CO coupling reaction does not need many active sites to get a high CO conversion.

Key words: carbon monoxide, coupling, methyl nitrite, dimethyl oxalate, palladium, alumina, support, supported catalyst