CuFe@SiO_2催化剂的制备及其在CO加氢合成低碳醇中的应用  

Preparation of SiO_2-coated CuFe catalysts for synthesis of higher alcohols from CO hydrogenation

作　　者：侯宾[1,2] 韩信有[1,2] 林明桂[1] 房克功[1] 

机构地区：[1]中国科学院山西煤炭化学研究所煤转化国家重点实验室,山西太原030001 [2]中国科学院大学,北京100049

出　　处：《燃料化学学报》2016年第2期217-224,共8页Journal of Fuel Chemistry and Technology

基　　金：国家自然科学基金(21473230);国家高技术研究发展计划(863计划;2012AA051002);中国科学院战略先导项目(XDA01020304)资助~~

摘　　要：采用共还原-原位包覆法制备一系列SiO_2包覆铜铁双金属纳米颗粒的催化剂(CuFe@SiO_2),借助N_2物理吸附、XRD、TEM、SEM-EDS、XPS和H_2-TPR等手段对不同Cu/Fe物质的量比的CuFe@SiO_2催化剂的物理化学性质进行了表征,并考察了催化剂在CO加氢合成低碳醇中的催化反应性能。结果表明,所制得的催化剂均为孔分布处于介孔范围的SiO_2包覆的铜铁纳米颗粒。随着Cu/Fe物质的量比降低,铜铁以复合氧化物存在的比例、总醇及C_(2+)OH选择性先增大后减小。其中,总醇及C_(2+)OH选择性在Cu/Fe物质的量比为1时达到最大,这是由于此时催化剂存在较多的CuFe_2O_4复合氧化物,铜铁协同作用较强,同时催化剂也呈现较大的比表面积及孔容,有利于所生成的醇更快扩散至催化剂表面而避免二次加氢生产烃类。A series of SiO2-coated CuFe（ SiO2@CuFe） catalysts with different Cu / Fe molar ratios were prepared by co-reduction and in situ coating method. The physicochemical properties of the catalysts were characterized with XRD,TEM,SEM-EDS,XPS and H2-TPR techniques and N2 sorption experiment. It was shown that well-dispersed Cu Fe nanoparticles were completely coated by mesoporous silica in the as-prepared catalysts. The content of Cu-Fe composite oxide in the catalyst and the selectivity of total alcohols and C2＋ alcohols both exhibit a volcano trend with the decrease of Cu / Fe molar ratios. When the Cu / Fe molar ratio was1,the largest amount of CuFe2O4 was formed,consequently,causing the strongest interaction between Cu and Fe. In addition,the obtained catalyst possessed higher BET surface area and larger BJH pore volume than the other samples. Thus, alcohol products easily diffuse into / out of its pores, thus avoiding the further hydrogenation to hydrocarbons. As a result,it shows the highest selectivity to total alcohols and C2＋ alcohols.

关 键 词：包覆结构 铜铁双金属 低碳醇 CO加氢 

分 类 号：O643[理学—物理化学]