凹凸棒石负载Cu-Fe-Co基催化剂组合体系用于CO加氢制备低碳醇

Attapulgite supported Cu-Fe-Co based catalyst combination system for CO hydrogenation to lower alcohols

  • 摘要: 采用浸渍法(IM)和浸渍燃烧法(IMSC)制备了凹凸棒石(ATP)及凹凸棒石-多孔硅胶微球混合物(ATPS)负载Cu-Fe-Co基改性费托催化剂,通过N2吸附-脱附、X射线衍射(XRD)、X射线光电子能谱(XPS)、扫描电镜(SEM)、透射电镜(TEM)、H2-程序升温还原(H2-TPR)和CO2-程序升温脱附(CO2-TPD)等手段对催化剂进行了表征,并将它们应用于CO加氢制备低碳醇反应。结果表明,IMSC较IM制备催化剂更有利于CuO的负载、分散和还原,促进H2和CO与Cu活性位的接触,但两者的最佳低碳醇合成温度均为280℃。通过对ATP和ATPS负载Cu-Fe-Co基催化剂(CFCK/ATP、CFCK/ATPS)与Cu/ZnO/Al2O3(CZA)甲醇催化剂的组合体系的优化,获得较理想的低碳醇合成催化剂组合体系CZA║CFCK/ATPS-IMSC。利用它们之间的"产物转化耦合效应",实现CO转化率为46.3%,低碳醇选择性为39.6%,C2+醇含量为22.7%。

     

    Abstract: Attapulgite (ATP) and ATP mixed with SiO2 microspheres (ATPS) supported Cu-Fe-Co modified Fischer-Tropsch (F-T) catalysts were prepared by impregnation method (IM) and impregnation-solution combustion method (IMSC). The catalysts were characterized by N2 adsorption-desorption, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), transmission electron microscopy (TEM), hydrogen temperature-programmed reduction (H2-TPR) and CO2-temperature programmed desorption (CO2-TPD). The catalysts were also applied to lower alcohols synthesis from CO hydrogenation. Results show that the IMSC method is much beneficial for the loading, dispersion and reduction of CuO on the prepared catalyst than IM method, which promots the touch of H2 and CO with Cu active site. The optimum reaction temperature for lower alcohols synthesis is 280℃ for the catalysts prepared by both methods. Through the optimization of catalyst combination system between ATP and ATPS supported Cu-Fe-Co based catalysts (CFCK/ATP, CFCK/ATPS) and Cu/ZnO/Al2O3 catalyst (CZA) for methanol synthesis, the ideal catalyst combination system, CZA‖CFCK/ATPS-IMSC, is obtained for lower alcohols synthesis. For the dual-bed configuration, a lower alcohols selectivity of 39.6% with the fraction of C2+ alcohols of 22.7% in oxygenates is achieved at CO conversion of 46.3% via the product conversion coupling effect.

     

/

返回文章
返回