摘要
以酸活化的凹凸棒石(Pa)为原料,用3-氨丙基三乙氧基硅烷(APTES)嫁接法制备了以3-氨丙基三乙氧基硅烷(3-aminopropyl-triethoxysilane,APTES)硅烷化凹凸棒石(PaAPTES)为载体负载Keggin型H5PMo10V2O40杂多酸催化剂(PMoV/PaAPTES),并用红外光谱分析、X射线衍射、BET比表面积测定对载体和催化剂进行了表征.以苯甲醛与乙二醇的缩合为探针反应,详细研究了各种参数对缩醛反应的影响,得出苯甲醛与乙二醇缩醛反应的最佳条件如下:乙二醇∶苯甲醛=1.75∶1、催化剂PMoV/PaAPTES的用量0.1g、带水剂环己烷8 mL,在115℃反应120min,苯甲醛的转化率为95.5%,苯甲醛环乙二缩醛的选择性为99.2%.所研制的PMoV/PaAPTES催化剂便于从反应体系中分离,可以重复使用多次.
The surface of acid-activated palygorskite （denoted as Pa） was modified by grafting 3-aminopropyl-triethoxysilane （ the silylated Pa, denoted as PaAPTEs ） for immobileizetion of molybdovanadophosphoric heteropoly acids （H5PMo10V2O40, denoted as PMoV）. The samples were characterized by Fourier transform infrared spectroscopy （ FTIR）, X-ray diffraction （ XRD）, and BET specific area measurement. The catalytic activity of the catalyst thus prepared was tested for the acetal of benzaldehyde with ethylene glycol, under the optimal reaction conditions, i. e. , ethylene glycol： acetophenone = 1.75： 1, 8 mL of cyclohexane as the water-carrying agents, with 0.1 g of PMoV/PaApTEs catalyst at 115 ℃ , and the selectivity of 99.2% for benzaldehyde cylic ethylic acetal at a benzaldehyde conversion of 95.5% was achieved within 120 min. The recycling tests show that the PMoV/ PaAerEs catalyst can be easily separated from the reaction system and can be used for many times.
出处
《分子催化》
EI
CAS
CSCD
北大核心
2011年第5期393-399,共7页
Journal of Molecular Catalysis(China)
关键词
杂多酸
硅烷化凹凸棒石
缩醛
催化
heteropoly acid
silanized palygorskite
acetal
catalysis
