Al改性Cu/ZnO催化剂催化苯胺制备N,N-二甲基苯胺  

Al modified Cu/ZnO catalysts for the catalytic synthesis of N,N-dimethylaniline from aniline

作　　者：孙中华 吴中[2] 王震 钱俊峰[1] SUN Zhonghua;WU Zhong;WANG Zhen;QIAN Junfeng(School of Petrochemical Engineering,Changzhou University,Changzhou 213164,Jiangsu,China;Catalysis Collaborative Innovation Cente,Changzhou University,Changzhou 213164,Jiangsu,China)

机构地区：[1]常州大学石油化工学院,江苏常州213164 [2]常州大学催化协同创新中心,江苏常州213164

出　　处：《精细化工》2022年第12期2497-2504,共8页Fine Chemicals

摘　　要：通过沉积沉淀法制备了Al改性Cu/ZnO催化剂,并利用XRD、BET、NH3-TPD、SEM、XPS对催化剂进行了表征。考察了铝源、铝添加量和催化剂焙烧条件对苯胺和甲醇N-甲基化反应制备N,N-二甲基苯胺(N,N-DMA)的影响,优化了N-甲基化反应工艺条件。得到的催化剂最佳制备条件为:以拟薄水铝石为铝源、n(Cu)∶n(Zn)∶n(Al)(即Cu/Zn/Al物质的量比)为1∶3∶1、焙烧温度为400℃,焙烧时间为3 h。在该条件下制备的Al改性Cu/Zn O催化剂用于苯胺的N-甲基化反应,在反应温度为250℃,反应压力为1.5 MPa,进料空速为0.3 h^(–1),氮气流量为150 m L/min,n(苯胺)∶n(甲醇)=1∶7的条件下,苯胺转化率达99.8%,N,N-DMA选择性达92.8%,催化剂进行了800 h稳定性实验,苯胺转化率稳定在99%以上,N,N-DMA选择性稳定在90%以上。Al modified Cu/ZnO catalysts were synthesized by deposition precipitation method and characterized by XRD,BET,NH3-TPD,SEM and XPS.The effects of aluminum source,aluminum content and catalyst calcination conditions on N-methylation reaction of aniline and methanol for N N-dimethylaniline(N,N-DMA)synthesis were investigated,and the N-methylation reaction conditions were optimized.The optimal preparation conditions of the catalyst were as follows:pseudo boehmite as aluminum source,Cu/Zn/Al molar ratio of 1∶3∶1,calcination temperature of 400℃,calcination time of 3h.The Al modified Cu/ZnO catalyst prepared under the above-optimized conditions was then used for the N-methylation of aniline.The results showed that the aniline conversion rate reached 99.8%,and the selectivity of N,N-DMA reached 92.8%under the conditions of reaction temperature 250℃,reaction pressure 1.5 MPa,feed space velocity 0.3 h^(–1),nitrogen flow rate 150 m L/min and aniline/methanol molar ratio 1∶7.Moreover,the aniline conversion rate remained above 99%,and the N,N-DMA selectivity was stably over 90%after the catalyst was recycled for 800 h.

关 键 词：苯胺 N N-二甲基苯胺 N-甲基化反应 Cu/ZnO/Al_(2)O_(3)催化剂 催化技术 

分 类 号：TQ426.83[化学工程]