介孔Cs3PMo12O40的制备、表征及其醛糖差向异构化反应的催化性能

以磷钼酸和氯化铯为原料、三嵌段共聚物F127为模板剂制备Keggin型介孔Cs₃PMo₁₂O₄₀(简称m-Cs₃PMo),通过X射线粉末衍射(XRD)、FT-IR、场发射扫描电子显微镜(FESEM)、透射电子显微镜(TEM)、N₂吸附-脱附测试和小角X射线散射(SAXS)对催化剂的组成、结构、形貌进行了表征。结果表明,m-Cs₃PMo属于立方相晶系,具有2.5和6.0 nm的蠕虫状介孔。以m-Cs₃PMo为催化剂考察其水相中D-葡萄糖、D-木糖和L-阿拉伯糖差向异构化反应的催化性能,并研究了反应温度、时间和催化剂用量对D-葡萄糖差向异构化反应的影响以及催化剂的循环使用性能,在循环使用过程中m-Cs₃PMo表现出良好的稳定性。

Preparation and Characterization of Mesoporous Cs3PMo12O40 Employed for Catalytic Epimerization Reaction of Aldoses

Keggin-type mesoporous Cs₃PMo₁₂O₄₀ (m-Cs₃PMo) has been prepared by using H₃PMo₁₂O₄₀ and CsCl as starting materials and amphiphilic triblock copolymer F127 as a template. The composition, structure, and morphology were characterized by powder X-ray diffraction (XRD), FT-IR, field emission scanning electron microscopy (FESEM), transmission electron microscope (TEM), N₂ adsorption-desorption test, and small-angle X-ray scattering (SAXS). The results show that m-Cs₃ PMo belongs to the cubic lattice system and owns 2.5 and 6.0 nm wormlike mesoporous pores. The catalytic activity of m-Cs₃PMo in aqueous epimerization of D-glucose, D-xylose, and L-arabinose was investigated. The effects of temperature, time, and catalyst amount on the D-glucose epimerization reaction and the recycling performance of the catalyst were also studied. During the recycling process, the catalyst activity and product selectivity did not decrease significantly, which showed good stability of m-Cs₃PMo.