Al-TS-1的合成及催化氧化性能

系统研究了Al掺杂TS-1(Al-TS-1)分子筛的合成及其催化氧化性能,采用X射线衍射、紫外-可见光谱、电感耦合等离子体发射光谱、扫描电镜、²⁷Al和²⁹Si固体核磁共振等手段对Al-TS-1样品进行了表征.结果表明,在合成过程中,Al的引入会影响TS-1中骨架Ti的形成,但当Al含量低于一定值(Al/Si≤0.005)时,其影响很小.Al-TS-1中骨架Al和骨架Ti均不对其相应的酸催化和催化氧化作用产生影响.骨架Al抑制了Al-TS-1在碱性应用体系中的与Ti相邻Si的溶脱,从而保护了骨架Ti活性中心.

Synthesis and catalytic oxidation performance of Al-TS-1

The preparation of titanium silicalite-1 (TS-1) containing Al (Al-TS-1) and its catalytic oxidation properties were investigated systematically. The features of Al-TS-1 were characterized using X-ray diffraction, ultraviolet-visible spectroscopy, inductively coupled plasma atomic emission spectroscopy, ²⁷Al magic-angle spinning and ²⁹Si magic-angle spinning nuclear magnetic resonance spectroscopies, and scanning electron microscopy. The results showed that incorporation of Al into the TS-1 framework influences the amount of framework Ti in Al-TS-1. However, when the Al/Si ratio is lower than 0.005, the amount of framework Ti in Al-TS-1 is hardly affected. Neither the Al centers nor the Ti centers in the Al-TS-1 framework influence the acidic catalytic and catalytic oxidation performance. Al in the Al-TS-1 framework suppressed desilication of silica species adjacent to framework Ti species in Al-TS-1 in a basic catalytic system, so Ti active sites in the Al-TS-1 framework could be protected.