HZSM-5固载苯并噻唑离子液体催化合成烷基糖苷及其动力学

Novel catalyst benzothiazole ionic liquid supported on HZSM-5 for synthesis of alkyl glycosides and its kinetics

摘要:

以自制苯并噻唑离子液体([HBth]HSO4)为活性组分，HZSM-5分子筛为载体，通过过量溶剂浸渍法制备了固载型苯并噻唑离子液体催化剂([HBth]HSO4/HZSM-5)并用于催化合成烷基糖苷，通过傅立叶变换红外光谱、N2物理脱附、场发射电子显微镜和X射线衍射对催化剂结构进行表征，结果表明，[HBth]HSO4被成功地引入到HZSM-5载体的表面及孔道内。当催化剂用量为1.5 wt%，反应温度为105℃，醇糖摩尔比n(葡萄糖):n(辛醇)=6:1时，辛基糖苷得率达148.8%（产物质量/葡萄糖的质量?100%）。底物拓展及催化剂稳定性研究结果表明，[HBth]HSO4/HZSM-5对烷基糖苷及其衍生物都具有良好的催化效果，且催化剂能稳定循环使用四次，活性组分流失是催化剂失活的主要原因。通过对烷基糖苷催化合成机理和动力学的研究，确定了动力学方程。

Abstract:

Novel catalyst benzothiazole ionic liquid supported on HZSM-5 ([HBth]HSO4/HZSM-5) was prepared via the excess solvent impregnation where benzothiazole ionic liquid ([HBth]HSO4) was used as the active component and hydrogen HZSM-5 molecular sieved as the carrier. The resulting catalyst was used as catalyst for synthesis of alkyl glycosides. Fourier transform infrared spectroscopy, N2 physical adsorption, field emission electron microscopy and X-ray diffraction results indicated that the benzothiazole ionic liquid was effectively loaded onto the surface and pores of the HZSM-5. When the amount of catalyst was 1.5 wt% of the total material mass, the reaction temperature was 105?C, and the molar ratio of glucose and octanol (n(glucose) : n(octanol)) was 6:1, the yield of octyl glycoside reached up to 148.8% (product mass/glucose mass ? 100%). The substrate expansion and catalyst stability results suggested that [HBth]HSO4/HZSM-5 had a good catalytic effect on alkyl glycosides, and the catalyst could be reused for four times without significant deactivation. After studying the catalytic synthesis mechanism and kinetics of alkyl glycosides, the kinetic equation is determined