KIT-1介孔分子筛的化学修饰及吸附性能

介孔分子筛MCM-41具有较大、可调的孔径和较高的比表面积，其骨架组成具有较强的可调变性．为该材料的应用提供了很大的空间。但全硅MCM-41分子筛在潮湿空气中，即使在室温条件下也会发生水解反应，使其介孔结构遭到破坏。前人已针对MCM-41分子筛稳定性不足的问题相继合成了稳定性较高的介孔分子筛KIT-1,

Chemical Modification and Adsorption of the Pure Silica Mesoporous Molecular Sieve KIT-1

The pure silica mesoporous molecular sieve (KIT-1) was chemically modified using both organic and inorganic precursors and characterized using FTIR, XRD, MAS NMR, TG-DSC and physical adsorption-desorption of nitrogen. Experimental results showed that the original mesoporous structure of the samples remained after modification. The IR and MAS NMR spectra demonstrated that the organic groups (-Si(CH₃)₃ and -OCH₂CH₃) had successfully grafted onto the inter-surface of KIT-1 and inorganic atoms(Al, Si) attached at silicon atoms located in the hydrophobic part of the surface of KIT-1, but the grafted samples showed a lower BET surface area ,pore volume and smaller pore size. Modification using trimethylchlorosilane(TMCS) and TEOS was found to result in a significant loss in porosity. The surface property of samples was measured through adsorption capacity for the vapour of water or toluene. The modification samples show a higher adsorption capacity to toluene as compared to the parent KIT-1. The hydrophobicity of the sample modified by TMCS is much higher than other modified samples. Chemical modifications can greatly improve the hydrothermal stability of KIT-1 material because of the changed surface property.