镧改性Cu-Fe/SiO2催化剂催化合成气制备低碳醇

Synthesis of Higher Alcohols from Syngas over Lanthanum Modified Cu-Fe/SiO2

采用超声辅助浸渍法制备了La-Cu-Fe/SiO2催化剂,考察了不同质量分数的La对催化剂催化合成气制备低碳醇反应性能的影响。通过XRD、氮气吸附-脱附、CO-TBD、H2-TPR对La-Cu-Fe/SiO2催化剂进行了表征。实验结果显示：加入La后有助于催化剂CuO特征衍射峰宽化,并使其比表面积增大至279.5 m2/g,Cu-Fe/SiO2催化剂加入相对于载体SiO2质量分数为5%的稀土元素La后,在3 MPa,300℃,催化剂0.30 g,V（H2）/V（CO）=2,流速30 m L/min条件下,CO转化率为29.2%,醇的时空产率达到128.7 g/（kgcat·h）,生成低碳醇与甲醇的质量比为0.79,表明La-Cu-Fe/SiO2催化剂有助于促进低碳醇的生成。

A series of La-Cu-Fe/SiO2 catalysts with different mass fraction of lanthanum were prepared by ultrasound assisted impregnation. Their catalytic performance for CO hydrogenation to higher alcohols were investigated. All catalysts were characterized by X-ray diffraction（XRD）,nitrogen adsorption-desorption isotherms, temperature-programmed desorption of CO（CO-TPD）, and temperature-programmed reduction of H2（H2-TPR）. The results showed that the addition of lanthanum could broaden the characteristic diffraction peak of the samples and increase the specific surface area of the samples and the maximum surface area was 279. 5 m2/g. The resulting catalyst with a lanthanum content of 5%（based on the mass of SiO2） promoted the formation of higher alcohols. The conversion rate of CO achieved 29. 2%,the space time yield of higher alcohols reached 128. 7 g/（kgcat·h）,and the higher alcohols/methyl alcohol mass ratio was 0. 79 over 0. 30 g La-Cu-Fe/SiO2 catalyst at 300 ℃,a H2/CO volume ratio of 2,gas velocity of 30 m L/min,a pressure of 3 MPa.