镧改性Cu-Fe/SiO2催化剂对合成气制备低碳醇的影响

Effect of La Modification Cu-Fe/SiO2 Catalyst on the Synthesis of Higher Alcohols from Syngas

摘要:

采用超声辅助浸渍法制备La-Cu-Fe/SiO2催化剂，考察稀土元素La对Cu-Fe/SiO2催化剂的催化性能影响。通过X射线衍射(XRD)，氮气吸附-脱附，CO的程序升温脱附(CO-TBD)，程序升温还原(H2-TPR)等测试技术对La-Cu-Fe/SiO2催化剂进行表征，并利用合成气制备低碳醇反应评价其催化性能。试验结果表明，Cu-Fe/SiO2催化剂加入稀土元素La后，有助于改善活性中心的分散程度，增大催化剂的比表面积，提高反应物CO的吸附浓度，减小活性中心的还原损失，从而促进C2 醇的生成，有效降低产物的甲醇含量。

Abstract:

La modified Cu-Fe/SiO2was prepared by ultrasound assisted impregnation. The effect of rare earth La additional on the catalytic performance of Cu-Fe/SiO2 was investigated. The catalysts were systematically characterized by techniques of X-ray diffraction (XRD), N2 adsorption isotherm, temperature-programmed desorption of CO (CO-TPD), and temperature-programmed reduction of H2 (H2-TPR), meanwhile the catalytic performance for CO hydrogenation to higher alcohols was also evaluated. The experimental results showed that with the modification of La, promoted the dispersion of active sites, the specific surface area was increased notably, enhanced adsorption capacity of CO and decreased reducibility of active sites. Therefore, the modified catalyst obviously improved the higher selectivity to C2 alcohols, and the content of methanol in reaction product was reduced significantly.