氨基功能化介孔分子筛KIT-1催化苯甲醛与丙二酸二乙酯缩合反应研究.pdf

584
化学世界
2012年
氨基功能化介孔分子筛KIT-1催化苯甲醛
与丙二酸二乙酯缩合反应研究
李惠云,韩玉民,吕蓓红,黄东枫,刘院英
(安阳师范学院化学化工学院,河南安阳455000
摘要:采用后合成法将3-氪丙基三甲氧基难烷嫁接在纯硅介孔分子筛KIT-1的孔道内外表面,
制备出含魚丙基基团的介孔分子筛样品NH2-KIT-1,并用于苯甲醛和两二酸二乙酯 Knoevenagel
缩合反应。利用博里叶变换一红外光谱(FTIR)、X射线粉末衍射(XRD)、N2吸附-脱附和酸滴定
等方法对样品的结构和表面碱含量进行了表征与测定。结果表明:魚两基已成功嫁接在分子筛
KTT-1表面,样品NH2-KIT-1仍保持了基体KIT-1的介孔结构和较高的比表面积、较大的孔容与
孔径。表面碱含量为1.105mmol/g样品(即30%NH2-KIT-1)在苯甲醛和丙二酸二乙酯
Knoevenagel缩合反应中表现的催化活性最好,140℃反应12h,苯甲醛的转化率为66.5%,重复
使用4次后,苯甲醛转化率下降到46.9%,表面藏含量下降到0.870mmol/g。催化剂活性下降的
原因可能是分子筛表面活性基团-(CH2)3-NH2·脱落造成的
关键词:介孔分子筛KIT-1;基功能化; Knoevenagel编合反应
中图分类号:O643.3;TQ426.6
文献标志码:A
文章编号:0367-6358(2012)10-0584-05
Knoevenagel Condensation of Benzaldehyde and Diethylmalonate Catalyzed b
Aminopropyl Functionalized KIT-1 Mesoporous Molecular Sieve
LI Hui-yun, HAN Yu-min, LU Bei-hong, HUANG Dong-feng, LIU Yuanying
( College of Chemistry and Chemical Engineering, Anyang Normal University, Henan Anyang 455000, China)
Abstract: Aminopropyl functionalized NH -KIT-1 catalysts for Knoevenagel condensation of benzaldehyde
and diethylmalonate were prepared by surface modification of pure silicon mesoporous molecular sieve
KIT-1 with 3-aminopropyltrimethoxy silane, and characterized by powder X-ray diffraction (XRD)
Fourier Transform infrared spectroscopy (FT IR), N2 adsorption-desorption isotherm and chemical
titration. Experimental results showed that the original mesoporous structure of the samples remained
after modification. The FT IR demonstrated that the organic group(-SI-(CH2)3-nh2 had successfully
grafted onto the inter-surface of KIT-1, but the grafted samples showed a lower BET surface area, pore
volume and smaller pore size. 30% NH2 -KIT-1 (1. 105 mmol/g of alkali sites) showed superior catalytic
activity in Knoevenagel condensation of benzaldehyde and diethylmalonate. The conversion of benzaldehyde
on the catalyst was 66.5% for the first time and 46.9% after four runs at 140 C following the drop of
surface alkali content down to 0. 870 mmol/g. The reason for the decline of catalytic activity is the decrease
of the surface activity group-(CH2)3 -NH2 on the sample.
Key words mesoporous molecular sieve KIT-1; aminopropyl functionalization Knoevenagel condensation
收稿日期:2012-03-19;修回日期:2012-09-10
基金项目:河南省教育厅科技攻关重点项目(12A150002),安阳市科技攻关项目(2010097)
作者简介:李惠云(1965-),女,河南安阳人,教授,主要从事介孔材料的合成与催化。E-mail:hyli739 2 sina,com。