Page 131 - 《精细化工》2022年第12期
P. 131
第 39 卷第 12 期 精 细 化 工 Vol.39, No.12
2 022 年 12 月 FINE CHEMICALS Dec. 2022
催化与分离提纯技术
Al 改性 Cu/ZnO 催化剂催化苯胺制备
N,N-二甲基苯胺
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孙中华 ,吴 中 ,王 震 ,钱俊峰
(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)
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、NH 3 -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/ZnO 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
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为 0.3 h ,氮气流量为 150 mL/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。
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
中图分类号:TQ426.83 文献标识码:A 文章编号:1003-5214 (2022) 12-2497-08
Al modified Cu/ZnO catalysts for the catalytic synthesis of
N,N-dimethylaniline from aniline
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SUN Zhonghua , WU Zhong , WANG Zhen , QIAN Junfeng
(1. School of Petrochemical Engineering, Changzhou University, Changzhou 213164, Jiangsu, China; 2. Catalysis Collaborative
Innovation Cente, Changzhou University, Changzhou 213164, Jiangsu, China)
Abstract: Al modified Cu/ZnO catalysts were synthesized by deposition precipitation method and
characterized by XRD, BET, NH 3-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
3 h. 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
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pressure 1.5 MPa, feed space velocity 0.3 h , nitrogen flow rate 150 mL/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.
Key words: aniline; N,N-dimethylaniline; N-methylation reaction; Cu/ZnO/Al 2O 3 catalysts; catalysis
technology
N,N-二甲基苯胺(N,N-DMA)在工业上应用广 可作溶剂、稳定剂、分析试剂等 [1-4] 。目前,N,N-DMA
泛,主要用作染料中间体,还可用于制香兰素,也 主要通过苯胺的 N-甲基化反应合成,工业上苯胺的
收稿日期:2022-08-22; 定用日期:2022-10-31; DOI: 10.13550/j.jxhg. 20220781
作者简介:孙中华(1976—),男,副研究员,E-mail:sunzhonghua@cczu.edu.cn。