活性金属负载量及配比对CuFe双金属催化剂催化合成混合醇的影响

Effects of loading amount and constitution of active metals on performance of CuFe bimetallic catalyst in mixed alcohols synthesis

采用液相还原法制备了CuFe双金属催化剂,考察了活性金属负载量及Cu、Fe摩尔比对催化剂反应活性和C_(2+)混合醇选择性的影响,分析了活性金属负载量、Cu/Fe摩尔比、催化剂结构及反应性能间的构-效关系,优化了催化剂的制备配方。结果表明,活性组分负载量的增大有助于提高催化剂的反应活性,但过量的金属负载量会导致活性组分发生团聚,影响总醇及C_(2+)混合醇的选择性;Cu/Fe摩尔比的增大抑制了催化剂的反应活性,但有助于增强CO吸附能力及Cu、Fe间的协同效应,提高产物中醇类及C_(2+)醇的选择性。综合考虑CO转化率、总醇及C_(2+)醇选择性,液相还原法制备CuFe双金属催化剂较适宜的活性组分总负载量为30%、铜铁摩尔比为3.0。

CuFe bimetallic catalyst is prepared by means of liquid phase reduction method,and the effects of loading amount and constitution of active metals on the reactive activity of catalyst and the selectivity of mixed alcohols in Fischer-Tropsch synthesis are researched.The structure-function relationships between the loading amount of active metals,molar ratio of Cu to Fe,catalyst structure and reaction performance are investigated and analyzed,and the preparation conditions are therefore optimized.Results show that higher loading amount of active components is helpful to improve the reactive activity of catalyst,but excessive metal loading will lead to agglomeration of active components,which affects the selectivity of total alcohols and C_(2+)mixed alcohols.Higher molar ratio of Cu to Fe restrains the activity of catalyst,but is helpful to enhance the catalyst's adsorption ability to CO and the interaction between copper and iron species,and hence increase the selectivity of total alcohols and C_(2+)mixed alcohols in products.Comprehensively considering CO conversion,the selectivities of total alcohols and C_(2+)mixed alcohols,the optimum loading amount of active components is 30%and the optimum molar ratio of Cu to Fe is 3.0 for the preparation of CuFe bimetallic catalyst via liquid phase reduction method.