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  

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

作　　者：董桂霖 罗祖伟 曹约强 周静红[2] 李伟[1] 周兴贵[2] DONG Guilin;LUO Zuwei;CAO Yueqiang;ZHOU Jinghong;LI Wei;ZHOU Xinggui(School of Chemical Engineering,East China University of Science and Technology,Shanghai 200237,China;State Key Laboratory of Chemical Engineering,East China University of Science and Technology,Shanghai 200237,China)

机构地区：[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

出　　处：《化工学报》2022年第1期232-240,共9页CIESC Journal

基　　金：国家重点研发计划项目(2018YFB0604700);国家自然科学基金项目(22008067)。

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AgNO_(3)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。Four amino-functionalized SiO_(2) nanospheres supported silver catalysts(Ag/AS)were synthesized in this work by adjusting the temperature of the reduction process for the AgNO_(3) 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,N_(2) 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.

关 键 词：草酸二甲酯 加氢 乙醇酸甲酯 催化剂 还原温度 活性 

分 类 号：TQ032.4[化学工程]