Al-TS-1的合成及催化氧化性能

Synthesis and catalytic oxidation performance of Al–TS‐1

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.

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.