热处理时间对CuZnAl催化剂合成C_(2+)OH性能的影响  

Effect of heat treatment time on the performance of CuZnAl catalysts in the synthesis of higher alcohols from syngas

作　　者：邓皓月 高志华[1] 黄伟[1] DENG Hao-yue;GAO Zhi-hua;HUANG Wei(Key Laboratory of Coal Science and Technology of Ministry of Education and Shanxi Province,Taiyuan University of Technology,Taiyuan 030024,China)

机构地区：[1]太原理工大学煤科学与技术教育部与山西省重点实验室,山西太原030024

出　　处：《燃料化学学报》2019年第5期532-539,共8页Journal of Fuel Chemistry and Technology

基　　金：国家自然科学基金(21336006);山西省自然科学基金(201601D011021;201601D202017)资助~~

摘　　要：采用完全液相法在不同热处理时间下制备了CuZnAl催化剂,利用X射线光电子能谱(XPS)、X射线衍射(XRD)、H_2程序升温还原(H_2-TPR)、NH_3吸附-脱附(NH_3-TPD-M S)和N_2物理吸附-脱附等方法对其结构进行了表征分析,并在浆态床反应器上对其催化合成气制C_(2+)OH的性能进行了研究。研究发现,延长热处理时间增强了催化剂中Cu和Al物种之间的相互作用力,改变了其中Cu^+的量,从而影响Cu^+-Cu^0活性位的协同作用。同时,热处理时间的延长减少了催化剂的表面酸量,增大了孔容和孔径;催化剂表面较少的弱酸位及较大孔容和孔径均有利于C_(2+)OH的生成。热处理时间为7 h时所制备的CuZnAl催化剂表现出了优良的低碳醇合成催化活性,CO转化率和总醇中C_(2+)OH的质量分数分别达到了38.1%和65.9%。A series of CuZnAl catalysts were prepared by the complete liquid-phase method with different heat treatment times and characterized by XPS,XRD,H2-TPR,NH3-TPD-M S and N2 adsorption-desorption;their catalytic performances in the synthesis of higher alcohols from syngas were investigated in a slurry bed reactor.The results indicate that an increase in the heat treatment time can enhance the interaction between the Cu and Al species and alter the amount of Cu+species over the CuZnAl catalysts,influencing the synergistic effect of Cu^+-Cu^0 sites. In addition,with the increase of heat treatment time,the surface acidity of CuZnAl catalyst decreases,accompanying with an increase in the pore volume and pore size;small amount of surface weak acid sites,large pore volume and large pore size are beneficial to the formation of higher alcohols. The CuZnAl catalyst obtained by heat-treating for 7 h exhibits excellent performance in the synthesis of higher alcohols,with a CO conversion of 38.1% and a higher alcohols mass fraction of 65.9% in the total alcohols.

关 键 词：完全液相法 CuZnAl催化剂 热处理时间 C2+OH Cu+-Cu0 

分 类 号：O643.3[理学—物理化学]