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提出了一种有效改善SBA-15介孔材料水热稳定性的简单溶剂热后处理方法.SBA-15材料经环己烷、甲苯和正丁醇等有机溶剂在157和190o C密闭容器中分别处理6–24h后,可呈现很好的水热稳定性.它们在800℃经100%水蒸气处理12h,依然能保持很好的有序介孔结构,比表面积可高达192–281m2/g.其中,经环己烷190o C溶剂热处理24h的样品表现出最优的水热稳定性.溶剂热处理能显著提升材料孔壁中类似Si(OSi)2(OH)2和Si(OSi)3OH结构的Si–OH基间脱水,形成稳定的Si(OSi)4结构,从而有效减少了SBA-15材料孔壁的缺陷.由此,介孔材料的水热稳定性得到明显改善.溶剂热处理对SBA-15材料水热稳定性的这种提升作用与所用溶剂性质、处理温度以及SBA-15前驱体的类型密切相关.其中,以低沸点的非极性溶剂处理焙烧后的SBA-15材料表现出最好的稳定化效果.该方法具有简单、低能耗的特点,其在制备高水热稳定的有序硅基介孔材料上有很好的潜在应用价值.
A simple solvent thermal aftertreatment method was proposed to effectively improve the hydrothermal stability of SBA-15 mesoporous materials.SBA-15 materials were treated with cyclohexane, toluene and n-butanol and other organic solvents in airtight containers of 157 and 190 ° C respectively After 6-24h, they showed good hydrothermal stability, and they were still well-ordered mesoporous structure with specific surface area up to 192-281m2 / g after treated with 100% steam at 800 ℃ for 12h. , And the sample hydrothermally treated with cyclohexane at 190 ° C for 24 h showed the best hydrothermal stability.The solvent heat treatment can significantly improve the Si-OH (Si (OH) 2) and Si (OSi) 3OH structures in the pore walls of the material The formation of a stable Si (OSi) 4 structure can effectively reduce the defects of the pore wall of the SBA-15 material, thereby remarkably improving the hydrothermal stability of the mesoporous material. This enhancement of thermal stability is closely related to the nature of the solvent used, the treatment temperature and the type of SBA-15 precursors, of which the best stability is obtained when the roasted SBA-15 material is treated with a low-boiling non-polar solvent The effect of this method is simple, low energy consumption, its preparation of high water thermal stability The orderly silicon-based mesoporous materials have good potential applications.