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    赵祥晴, 黄岩, 张维义, 岳志, 程振民. 铜晶粒尺寸及其稳定性对醋酸乙酯加氢制乙醇的影响[J]. 华东理工大学学报(自然科学版), 2020, 46(1): 1-9. DOI: 10.14135/j.cnki.1006-3080.20181212004
    引用本文: 赵祥晴, 黄岩, 张维义, 岳志, 程振民. 铜晶粒尺寸及其稳定性对醋酸乙酯加氢制乙醇的影响[J]. 华东理工大学学报(自然科学版), 2020, 46(1): 1-9. DOI: 10.14135/j.cnki.1006-3080.20181212004
    ZHAO Xiangqing, HUANG Yan, ZHANG Weiyi, YUE Zhi, CHENG Zhenmin. Influences of the Size and Stability of Cu Crystallite on Hydrogenation of Ethyl Acetate for Preparation of Ethanol[J]. Journal of East China University of Science and Technology, 2020, 46(1): 1-9. DOI: 10.14135/j.cnki.1006-3080.20181212004
    Citation: ZHAO Xiangqing, HUANG Yan, ZHANG Weiyi, YUE Zhi, CHENG Zhenmin. Influences of the Size and Stability of Cu Crystallite on Hydrogenation of Ethyl Acetate for Preparation of Ethanol[J]. Journal of East China University of Science and Technology, 2020, 46(1): 1-9. DOI: 10.14135/j.cnki.1006-3080.20181212004

    铜晶粒尺寸及其稳定性对醋酸乙酯加氢制乙醇的影响

    Influences of the Size and Stability of Cu Crystallite on Hydrogenation of Ethyl Acetate for Preparation of Ethanol

    • 摘要: 采用并流共沉淀法制备了一系列铜基催化剂,考察了不同稀土(Y、La、Ce、Pr)改性对Cu/SiO2催化剂催化醋酸乙酯(EA)加氢制乙醇的影响,并采用X射线衍射仪(XRD)、透射电子显微镜(TEM)、Brunauer-Emmett-Teller(BET)、氢气程序升温还原(H2-TPR)、氨气程序升温脱附(NH3-TPD)和X射线光电子能谱仪(XPS)等表征手段对催化剂进行了分析。结果表明,稀土(Y、La、Ce、Pr)改性能够减小铜晶粒尺寸,增大铜组分分散度和孔径,使催化剂更易还原,同时也能调节催化剂表面酸性和n(Cu0)/n(Cu0+Cu+),从而提高催化剂的加氢活性。其中,Y改性Cu/SiO2催化剂的加氢活性最高,且具有良好的高温抗烧结能力和稳定性能。

       

      Abstract: Hydrogenation of ethyl acetate (EA) is a promising route for the synthesis of ethanol (EtOH), but the involved catalysts have a series of problems, such as low hydrogenation activity, easy sintering at high temperature, and poor stability. Therefore, it’s necessary to develop catalysts with high catalytic efficiency and stability for the hydrogenation of EA to prepare EtOH. Rare earth elements have abundant energy level structure and unique 4f orbital, and their oxides modified catalysts generally have high adsorption selectivity, excellent thermal stability and other advantages. In this paper, the Cu/SiO2 catalysts modified by different rare earth elements (Y, La, Ce and Pr) were prepared by co-precipitation method, and characterized by XRD, TEM, BET, H2-TPR, NH3-TPD and XPS. The effects of the modifications on Cu/SiO2 with different rare earth elements (Y, La, Ce and Pr) on the catalytic performances for hydrogenation of EA were investigated in a fixed bed reactor. The experimental results show that the modifications with rare earth elements (Y, La, Ce and Pr) can reduce the crystallite size of copper in the catalyst, thereby accelerating the dispersion of copper active components and increasing the pore size of the catalyst, by which the catalyst is easier to be reduced, and its surface acidity is tunable. As a result, the catalytic activity of the Cu/SiO2 catalyst for the hydrogenation is significantly increased. Furthermore, Y-modified Cu/SiO2 catalyst showed the highest hydrogenation activity due to the smallest copper crystallite size, the highest copper dispersion, the largest pore diameter, and the suitable surface acidity and n (Cu0)/n (Cu0+Cu+). Under the reaction conditions of 250 ℃, 2.0 MPa, weight hourly space velocity (WHSV) of 5.0 h−1 and the molar ratio of H2 to EA of 5.0, the conversion of EA could reach 96.3% with a selectivity of EtOH of 99.1%. Also, Y-modified Cu/SiO2 catalyst showed excellent stability and resistance to sintering.

       

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