催化学报

催化学报 ›› 2008, Vol. 29 ›› Issue (4): 325-329.

• 研究论文 • 上一篇    下一篇

Pd/α-Al2O3催化CO偶联制草酸二甲酯的反应机理

林茜,计扬,谭俊青,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:2008-04-25 出版日期:2008-04-25 发布日期:2012-03-22

Mechanism of CO Coupling to Dimethyl Oxalate over Pd/α-Al2O3

LIN Qian, JI Yang, TAN Junqing, XIAO Wende*   

  1. UNILAB, State Key Laboratory of Chemical Reaction Engineering, East China University of Science and Technology, Shanghai 200237, China
  • Received:2008-04-25 Online:2008-04-25 Published:2012-03-22

PDF

950

被引次数

81

摘要： 采用傅里叶变换红外光谱对Pd/α-Al2O3催化剂上CO偶联制草酸二甲酯的反应机理进行了研究. 通过改变原料气CO和亚硝酸甲酯进入原位反应池的顺序,使反应过程更加直观. 实验结果表明, CO偶联反应发生在桥式吸附态的CO和气相的亚硝酸甲酯之间, CO的吸附为反应的控制步骤. 亚硝酸甲酯在Pd/α-Al2O3上易分解,生成甲醇、甲醛和甲酸甲酯. 在反应初期使CO先在催化剂表面吸附饱和,可以有效控制该分解反应的进行.

关键词: 一氧化碳, 桥式吸附, 亚硝酸甲酯, 偶联, 草酸二甲酯, 钯, 反应机理, 傅里叶变换红外光谱

Abstract: The reaction mechanism of CO coupling to dimethyl oxalate over Pd/α-Al2O3 was studied by in situ FT-IR spectroscopy. The adsorption of two reactants, CO and methyl nitrite, on the catalyst was observed. Methyl nitrite can easily catalytically dissociate into methanol, formaldehyde, and methyl formate. By changing the addition sequence of the two reactants into the in situ reactor, the process of the coupling reaction was clearly observed. The results show that bridged adsorbed CO reacts with free methyl nitrite gas, and the key step of the whole reaction is the CO adsorption.

Key words: carbon monoxide, bridged adsorption, methyl nitrite, coupling, dimethyl oxalate, palladium, reaction mechanism, Fourier transform infrared spectroscopy