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分别用水热合成法和气相四氯化钛(TiCl4)接枝法制备了Ti-HMS和Ti/HMS催化剂.表征结果表明,经过气相TiCl4接枝后的样品依然保持HMS(Hexagonal Mesoporous Silica,缩写为HMS)介孔材料特征,钛(Ti)物种主要以四配位的活性位形式存在.经过甲基接枝处理的催化材料,增加了表面的疏水性.丙烯环氧化反应结果表明,SN-Ti/HMS具有更高的催化性能.在2 500 h的稳定试验中,过氧化氢异丙苯(CHP)转化率大于99.0%,环氧丙烷(PO)选择性大于96.0%.研究和优化了环氧化反应工艺条件.采用浓度为30%的CHP为原料,CHP重量空速为1.0 h-1,床层温度为100℃,反应压力为3.0 MPa.
The Ti-HMS and Ti / HMS catalysts were prepared by hydrothermal synthesis and TiCl4 grafting method respectively. The characterization results showed that the samples grafted with TiCl4 in gas still retained HMS (Hexagonal Mesoporous Silica, abbreviated as HMS) mesoporous materials. The Ti species mainly exist in the active site of tetracoordinate coordination. The catalytic materials with methyl grafting increased the surface hydrophobicity.The results of epoxidation of propylene showed that SN- The catalytic performance of Ti / HMS was better than that of Ti / HMS, the conversion of cumene hydroperoxide (CHP) was over 99.0% and the selectivity to propylene oxide (PO) was over 96.0% The conditions of epoxidation reaction were as follows: the CHP weight-space velocity was 1.0 h-1, the bed temperature was 100 ℃, and the reaction pressure was 3.0 MPa.