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.