纳米介孔分子筛Sm-MCM的合成与表征

Characterization and Synthesis of Nanosized Mesoporous Molecular Sieve Sm-MCM

利用有机相-水相界面共沉淀溶胶支持自组装方法制备了颗粒大小约为10～15 nm稀土嵌入纳米介孔分子筛Sm-MGM(1:10).其BET比表面积、孔容和孔径分别为621 m2·g-1,1.25 cm3·g-1和8.0 nm.稀土掺杂能改善纳米分子筛的尺寸.29Si-MAS NMR分析测试出样品的波谱峰-44,-58,-67,-76,-89,-107,-110 ppm,分别对应七个不同化学环境q0,q1,q2,q3,Q2,Q3,Q4[(SiO)4-nSi-(O-Sm-)n(n=4,3,2,1),(SiO)4-mSi-(OH)m(m=2,1,0)].表明稀土元素已嵌入分子筛的骨架.不同的样品的巨大比表面积和大的孔容比表明分子筛为典型的介孔结构,也说明这些介孔物质材料在800℃的高温下有非常好的热稳定性.把硅胶基质介孔分子筛的红外吸收峰970 cm-1归属为硅羟基的扭曲振动.Sm-MCM的发射光谱归属于Sm3+离子的4L17/2→6Hn/2(n=11,13,15)跃迁发射.

The nanosized Sm-MCM （1： 10） mesoporous molecular sieve was synthesized by means of sol-gel- assisted self-assembly at the interface of non-aqueous and aqueous phase with hydrolyzation reaction routine under basic conditions at room temperature. The HRTEM image shows that the samples have uniform particles with a dia-meter of 10 ～ 15 nm. The BET surface area, porosity and pore-size of Sm-MCM （ 1： 10） are 621m^2·g^-1,1.25cm^3·g^-1,and 8nm.That results of ^29Si-MAS NMR show that q^0,q^1,q^2,q^3,Q^2,Q^3,Q^4[ （SiO）4-nSi-（O-Sm-）n（n = 4,3,2 ,1）, （SiO）4-mSi-（OH）m（m = 2,1,0） ] at -44, -58, -67, -76, -89, -107, -110 ppm, respectively, proves that the ion of Sm^3＋ has incorporated the framework of Si-O. The FTIR results show that the peaks near 970 cm^ -1 are assigned to the deformation vibration of silanol group. The as-product is calcined at 800℃ and the mesoporous material possess enormous specific areas and large porosity, it shows that the mesoporous material is uhrastable. The emission spectra of Sm-MCM, vesting 4 6 in the transitions ^4L17/2→^6 Hn/2 （ n = 11,13,15 ） of Sm^3 ＋ ion, show that samarium ion exists in special chemical environment of Sm-MCM.