Organotin compounds immobilized on mesoporous silicas as heterogeneous catalysts for direct synthesis of dimethyl carbonate from methanol and carbon dioxide
Organotin compounds immobilized on mesoporous silicas as heterogeneous catalysts for direct synthesis of dimethyl carbonate from methanol and carbon dioxide
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固定在介孔二氧化硅上的有机锡化合物作为多相催化剂用于甲醇和二氧化碳直接合成碳酸二甲酯
DOI：
10.1016/j.apcata.2009.10.022
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发表时间：
2010-01-05
影响因子：
5.5
通讯作者：
Li, Ruifeng
中科院分区：
文献类型：
--
作者：
Fan, Binbin;Li, Hongyu;Li, Ruifeng
通过XRD、N-2吸附/脱附实验、FTIR、漫反射UV-vis和C-13 CP/MAS NMR等方法，证明了有机锡化合物（MeO）（2）ClSi（CH 2）（3）SnCl 3接枝到一系列中孔SiO2上。CH_3 O_-进一步取代Sn ~（4+）上的Cl ~-，形成了一系列具有活性的多相催化剂，用于甲醇和CO_2直接合成碳酸二甲酯。这些催化剂的催化性能取决于介孔氧化硅的结构、晶粒大小和表面性质。SBA-15作为宿主菌比SBA-16和大孔la 3d具有上级优势。此外，用于去除吸附在介孔二氧化硅中的表面活性剂的方法由于显著影响介孔二氧化硅的表面积和表面羟基的浓度而对催化性能具有强烈影响。应提供用乙醇-HCl溶液萃取表面活性剂的方法。在达到热力学平衡之前，增加反应时间、反应温度、甲醇用量和CO2压力显著增加碳酸二甲酯的产率。在反应体系中加入脱水剂也可提高碳酸二甲酯的产率。2，2-二甲氧基丙烷的碳酸二甲酯产率远高于3A分子筛和正硅酸四甲酯。所制备的有机锡/介孔二氧化硅催化剂是高度稳定的，如通过以下发现所证实的：在SBA-15-固定化的有机锡化合物上获得的碳酸二甲酯产率在相同反应条件下再生的六次重复运行内没有降低，并且反应后Sn物种的四面体配位状态得以保持。(C)2009爱思唯尔有限公司版权所有。
Organotin compounds of (MeO)(2)ClSi(CH2)(3)SnCl3 have been grafted on a series of mesosporous silicas, as proved by XRD, N-2 adsorption/desorption experiments and FTIR, diffuse reflectance UV-vis and C-13 CP/MAS NMR spectroscopies. A further substitution of Cl- bonded to Sn4+ by CH3O- led to the formation of a series of active heterogeneous catalysts for the direct synthesis of dimethyl carbonate from methanol and CO2. The catalytic properties of these catalysts depended on the structure, crystal size and surface properties of mesoporous silicas. SBA-15 as a host was superior to SBA-16 and large-pore la3d. in addition, the methods used for removing surfactants occluded in mesoporous silicas had strong influences on the catalytic performance as a result of significantly affecting the surface areas and the concentrations of surface hydroxyl groups of the mesoporous silicas. The extraction of surfactants by an ethanol-HCl solution should be available. An increase in the reaction time, reaction temperature, methanol amount and CO2 pressure significantly increased the dimethyl carbonate yield before reaching thermodynamic equilibrium. The dimethyl carbonate yield could also be increased by adding dehydration agents to the reaction system. 2,2-Dimethoxypropane gave a much higher dimethyl carbonate yield than 3A molecular sieve and tetramethyl orthorsilicate. The prepared organotin/mesoporous silica catalysts were highly stable, as corroborated by the findings that the dimethyl carbonate yield obtained over the SBA-15-immoilized organotin compound did not decrease within six repeated runs with regeneration under the same reaction conditions and that the tetrahedral coordination state of Sn species was maintained after reaction. (C) 2009 Elsevier B.V. All rights reserved.