磺酸功能化的MCM-41催化三乙酸甘油酯与甲醇的酯交换反应

摘要

通过在孔壁上覆盖糠醇聚合物,于不同温度下用浓硫酸直接进行磺化制备了一系列磺酸基功能化的MCM-41介孔材料,并用氮气吸附-脱附、XRD、XPS和红外光谱等方法对其进行了结构表征,以三乙酸甘油酯和甲醇的酯交换反应为模型反应研究了生物柴油的制备.结果表明,在介孔结构完好的情况下,一定数量的磺酸基嫁接到了MCM-41的孔擘上.催化剂在酯交换反应中表现出良好的反应活性和选择性,其中SO<,3>HMCM-41(200℃)催化剂在反应进行6 h时,三乙酸甘油酯的转化率达到99.4%,与液体H2SO<,4>等效,反应进行180 rain时,乙酸甲酯和甘油的选择性分别达到71.5%和17.4%.%A series of sulfonic acid-functionalized MCM-41 catalysts was synthesized through coating and polymerization of the furfuryl alcohol on the pore walls, and then sulfonated in the presence of sulfuric acid at different temperatures. The catalysts strutures were characterized by nitrogen adsorption measurements using the procedure according to Brunauer, Emmet and Taller( BET), X-ray diffraction ( XRD), X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared resonance spectroscopy (ＦTIR), and studied for the transesterification of triacetin with methanol as a model reaction for biodiesel production. The results show that a number of sulfonic groups attach on the pore walls with the mesopores of MCM-41 not being damaged; the catalysts show very high activity and selectivity in the transesterification reaction, and the SO3H-MCM-41 (200 。C ) exhibits the highest triacetin conversion(99.4％ ) after 6 h which has the same activity as H2SO4, the selectivities of methyl acetate and glycerol are 71.5％ and 17.4％ after 180 min, respectively.