碱性金属改性Cu-Fe双孔载体催化剂结构和低碳醇合成反应性能研究  

EFFECT OF BASIC METAL ADDITIVES ON Cu-Fe CATALYST WITH BIMODAL PORE SUPPORT FOR HIGHER ALCOHOLS SYNTHESIS

作　　者：刘建国[1,2] 定明月[1] 王铁军[1] 马隆龙[1] 

机构地区：[1]中国科学院可再生能源与天然气水合物重点实验室,广州510640 [2]中国科学院研究生院

出　　处：《石油炼制与化工》2013年第1期22-27,共6页Petroleum Processing and Petrochemicals

基　　金：国家自然科学基金(51076158;51036006);国家科技支撑项目(2011BAD22B06)

摘　　要：采用超声浸渍法制备了不同碱性金属改性的Cu-Fe双孔载体催化剂,利用N_2物理吸附、H_2-TPR、XRD、XPS等表征手段考察了Li,Ca,Na,K等碱性金属对催化剂结构的影响,并在固定床反应器中评价了催化剂的低碳醇合成反应性能。结果表明:将小孔引硅溶胶与大孔硅凝胶结合可形成SiO_2-SiO_2双孔载体结构;Li和Ca的添加可促进Cu-Fe双孔载体催化剂表层CuO的生成,降低Fe_2O_3的含量,削弱Cu-Fe之间的作用力,从而促进甲醇产物的生成;Na和K助剂的添加则可促进Cu、Fe氧化物在催化剂表层的生成,加强Cu-Fe协同作用,从而提高低碳醇合成反应的活性和C_2以上醇类产物的选择性;与其它碱性金属相比,K助剂的添加使Cu-Fe双孔载体催化剂具有最高的低碳醇合成反应活性和醇时空产率。Cu-Fe bimodal pore catalysts modified with basic metal additives for higher alcohols synthesis （HAS） were prepared by an ultrasonic impregnation method. The study was undertaken to investigate the effects of various basic metal additives on the microstructures and HAS performances of catalysts. Several techniques, including N2 physical adsorption, temperature programmed reduction of hydrogen, X-ray diffraction and X-ray photoelectron spectroscopy, were combined to characterize these catalysts. The characterization results indicated that bimodal pore support was formed with the addition of small pore silica sol into the macroporous silica gel. Adding additives containing Ca and Li into Cu-Fe bimodal catalyst increased the amount of CuO and decreased that of Fe203 on the surface layer of the catalyst, which could weaken the interaction of Cu-Fe-O and promote the formation of methanol. The addition of Na and K additives increased the amounts of copper and iron species on the surface layer, enhancing the synergistic effect of Cu-Fe and improving the HAS activity and selectivity of C2＋ OH. Among these four basic metal additives, catalyst with K additive exhibited the best activity and space time yield of higher alcohols.

关 键 词：费-托合成 低碳混合醇 碱性金属 双孔载体 铜铁催化剂 

分 类 号：O643.36[理学—物理化学]