将三甲基氯化锡与Al-MCM-41介孔分子筛在N2气气氛中135℃回流4.5 h,得到表面键合有机锡的分子筛(CH3)3Sn-O-MCM-41[(CH3)3SnM].采用电感耦合等离子体质谱(ICP-MS)、有机元素分析、红外光谱、N2吸附-脱附、热重分析(TG)、NH3程序升温脱附(NH3-TPD)、X射线多晶衍射(XRD)和透射电子显微镜等测试技术对样品的组成、结构和表面物理化学性质进行表征.结果表明,有机锡接枝率可达14.44%;接枝前后分子筛的NH3-TPD表面酸量(NH3)由0.652 6 mmol/g增加至1.294 4 mmol/g.接枝后分子筛的比表面积减小,孔容变大,孔径变小,仍保持六方介孔结构;接枝分子筛(CH3)3SnM用于催化合成乙酸异戊酯,当n(异戊醇)∶n(冰乙酸)=1.0∶1.0,w(催化剂)=5%,138℃,回流5 h,反应转化率为96%;催化剂重复使用5次,酯化转化率仍可达到86%.%Trimethyltin chloride and mesoporous molecular sieve Al-MCM-41 were heated at 135 ℃ for 4. 5 h under stirring conditions and nitrogen atmosphere, to obtain ( CH3 )3 Sn-O-MCM-41 [(CH3)3SnM]. The composition, structure, and physical and chemical surface properties of the resulted solid were characterized by inductively coupled plasma mass spectrometry(ICP-MS) , Fourier transform infrared spectroscopy ( FTIR) , N2 adsorption-desorption, NH3 cheihisorption ( NH3-TPD ) , X-ray diffraction ( XRD ), and transmission electron microscopy (TEM). The results showed that the grafting yield was 14. 44％ for Sn in mass fraction. TPD acid ( NH3 ) of Al-MCM-41 before and after reaction with trimethyltin chloride increased from 0. 652 6 mmol/g to 1. 294 4 mmol/g. ( CH3 ) 3SnM resulted in a decrease of the surface areas and the pore size and an increase of the mesopous volume and surface acidity compared to Al-MCM-41. The thermal stability for the sample grafted with organotin was improved. The sample that was grafted with organotin on the Al-MCM-41 had the ordered hexagonal mesopore structure. The conversion rate is 96％ when n( isoamyl alcohol) ∶ n( acetic acid) =1.0:1.0, ω( (CH3)3SnM) =5％, 138 ℃ for5 h, and the catalyst can be reused. A conversion rate of 86％ can be attained when catalyst was reused five times under the same catalytic conditions.
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