化工学报 ›› 2022, Vol. 73 ›› Issue (1): 232-240.DOI: 10.11949/0438-1157.20211097

• 催化、动力学与反应器 • 上一篇    下一篇

液相还原温度对草酸酯加氢制乙醇酸甲酯银硅催化剂性能的影响

董桂霖1(),罗祖伟2,曹约强2(),周静红2,李伟1,周兴贵2   

  1. 1.华东理工大学化工学院,上海 200237
    2.华东理工大学化学工程联合国家重点实验室,上海 200237
  • 收稿日期:2021-08-09 修回日期:2021-09-16 出版日期:2022-01-05 发布日期:2022-01-18
  • 通讯作者: 曹约强
  • 作者简介:董桂霖(1984—),男,博士研究生,gldong1984@139.com
  • 基金资助:
    国家重点研发计划项目(2018YFB0604700);国家自然科学基金项目(22008067)

Effect of liquid-phase reduction temperature on performance of silver-silica catalysts for hydrogenation of dimethyl oxalate to methyl glycolate

Guilin DONG1(),Zuwei LUO2,Yueqiang CAO2(),Jinghong ZHOU2,Wei LI1,Xinggui ZHOU2   

  1. 1.School of Chemical Engineering, East China University of Science and Technology, Shanghai 200237, China
    2.State Key Laboratory of Chemical Engineering, East China University of Science and Technology, Shanghai 200237, China
  • Received:2021-08-09 Revised:2021-09-16 Online:2022-01-05 Published:2022-01-18
  • Contact: Yueqiang CAO

摘要:

以表面氨基功能化修饰的介孔二氧化硅纳米微球(AS)为载体,乙醇为还原剂,通过调变前体AgNO3的还原温度,制得了四种不同银催化剂(Ag/AS),结合催化剂表征技术和催化性能研究,探讨了液相还原温度对银硅催化剂上草酸二甲酯(DMO)加氢制乙醇酸甲酯(MG)反应性能的影响规律。X射线衍射、氮气物理吸附、透射电镜、X射线光电子能谱等研究结果表明,Ag/AS催化剂随着还原温度的升高Ag颗粒的平均粒径呈指数型增大,对应的表面Ag原子配位数也随之增大。DMO吸附的原位红外光谱和DMO程序升温脱附实验表明,还原温度升高引起的表面原子配位数的增大,减弱了DMO在催化剂上的吸附进而降低了DMO加氢制MG的活性。

关键词: 草酸二甲酯, 加氢, 乙醇酸甲酯, 催化剂, 还原温度, 活性

Abstract:

Four amino-functionalized SiO2 nanospheres supported silver catalysts (Ag/AS) were synthesized in this work by adjusting the temperature of the reduction process for the AgNO3 precursor with using ethanol as the reductant. The catalyst characterization and the catalytic performance tests clearly show the effect of liquid-phase reduction temperature on the performance of Ag/AS catalysts for hydrogenation of dimethyl oxalate (DMO) to methyl glycolate (MG). X-Ray diffraction, N2 physical adsorption, transmission electron microscopy and X-ray photoelectron spectroscopy measurements indicate that the particle size of Ag particles increases significantly with the increasing reduction temperature, which results in increase of surface Ag coordination number. In-situ infrared spectroscopy of DMO adsorption and DMO temperature-programmed desorption experiments show that the increase in the coordination number of surface atoms caused by the increase of reduction temperature weakens the adsorption of DMO on the catalyst and thus reduces the activity of DMO hydrogenation to MG.

Key words: dimethyl oxalate, hydrogenation, methyl glycolate, catalyst, reduction temperature, reactivity

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