Ag改性层状硅酸铜催化剂的草酸二甲酯加氢合成乙醇酸甲酯性能研究

Study on performance of Ag-modified layered copper silicate catalyst for hydrogenation of dimethyl oxalate to methyl glycolate

  • 摘要: 本研究采用溶胶-凝胶法制备了一系列CuAg/SiO2催化剂用于草酸二甲酯(DMO)加氢合成MG,使用XRD、N2吸附-脱附、FT-IR、TEM、SEM、H2-TPR、XPS等方法对其结构进行表征,重点考察了Ag含量对催化剂结构及性能的影响。当Ag负载量为5%时,5Ag-Cu/SiO2催化剂活性最高,DMO的转化率和MG的选择性分别可达83.7%和72.2%。表征结果表明,适量Ag的引入可有效提高活性组分Cu的分散度,增加催化剂表面Cu+的含量,从而提高催化剂活性。此外,Ag与Cu之间的电子转移可以有效稳定Cu+,进而提高催化剂的稳定性。

     

    Abstract: Methyl glycolate (MG) is a high value-added chemical intermediate and widely used in the fields of medicine, chemical industry, fodder and dyes. A series of CuAg/SiO2 catalysts were prepared by sol-gel method for hydrogenation of dimethyl oxalate to MG. The structure of catalysts was characterized by XRD, N2-physical adsorption, FT-IR, TEM, H2-TPR, and XPS, and the influence of Ag loading on catalytic performance was investigated. The 5Ag-Cu/SiO2 catalyst with Ag loading of 5% exhibited the best catalytic performance with DMO conversion of 83.7% and MG selectivity of 72.2%. The characterization results showed that introducing appropriate amount of Ag not only improved the dispersion of copper species, but also increased the content of Cu+, thereby improving the catalytic activity of CuAg/SiO2 catalysts. In addition, the electron transfer between Ag and Cu could effectively stabilize Cu+, and eventually improved the stability of the catalyst.

     

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