摘要
通过表面反应制备了气凝胶SiO2负载无水四氯化锡催化剂并应用于顺酐与正丁醇的酯化反应.结果表明,酯化产物主要为马来酸二丁酯(DBM)与富马酸二丁酯(DBF),其优化条件为:载体SiO2气凝胶焙烧温度500℃,物料摩尔比顺酐∶正丁醇:催化剂=1∶2∶0.0028,反应时间6 h.并且通过XRD,FTIR,DRUV-vis,N2物理吸附以及元素分析技术对所合成催化剂进行表征.结果表明:无水四氯化锡成功负载于SiO2气凝胶表面,在催化酯化反应当中实现了86.1%的顺酐转化率,此结果接近于国内外所报道的均相体系成果,同时在催化回收利用六次后,其活性虽逐步下降,但仍是空白的2倍.分析测试表明,反应过程中Cl的流失量较大、反应物及产物在催化剂表面产生了吸附,这些可能是导致催化活性下降的主要原因.
Dibutyl maleate（DBM） and dibutyl fumarate（DBF） are important intermediates extensively used in industrial application.The current paper reports a study on the efficacy of tin tetrachloride supported on silica aerogels catalyst（Sn/Si） in the esterification of maleic anhydride（MA） with butanol（BO） at reflux in which DBM and DBF are synthesized directly.The catalyst was characterized by X-ray powder diffraction（XRD）,Infrared（FTIR） spectra,UV-vis diffuse reflectance spectra（DRUV-vis）,N2 sorption and element analysis.The optimal reaction conditions were confirmed as follows： calcination temperature of silica aerogels was 500 ℃,reaction time was 6 h,mol ratio of reactants was 1∶ 2∶ 0.0028（MA∶ BO∶ Sn/Si）.The conversion of MA was up to 86.1%,and the selectivity to DBM and DBF were 68.3% and 1.84% respectively,which almost same as the homogeneous catalyst system.And the Sn/Si catalyst kept a reasonable activity after 6 times reused cycles.The lost of Cl and the reaction of MA,BO,DBM,DBF with the catalyst surface could result in the decrease of the catalytic activity.
出处
《分子催化》
EI
CAS
CSCD
北大核心
2012年第1期39-45,共7页
Journal of Molecular Catalysis(China)
基金
supported by National Nature Science Foundation of China.Grant No.21073114
Key Science and Technology Program of Shanxi Province,China.Grant No.20090321059
