表面富钛TS-1分子筛的表征与评价

CHARACTERIZATION AND EVALUATION OF TS-1 WITH ENRICHED Ti SPECIES ON ITS SURFACE

钛硅分子筛(TS-1)是MFI结构的含Ti杂原子分子筛,可与低浓度H2O2一起催化氧化多种有机物。将活性中心Ti分布在TS-1分子筛的表面,则有利于减少扩散的影响。制备了表面富钛TS-1分子筛,采用XRD、XRF、SEM、TEM、FT-IR等手段对其进行了表征。结果表明,制备所得表面富钛TS-1分子筛的Ti在TS-1分子筛表面的径向分布具有中间少边沿多的性质,其他物化性质则与常规TS-1分子筛相近。通过催化反应发现表面富钛TS-1分子筛有反应诱导期更短的突出特点,有较好的应用前景。

Titanium silicalite （TS-1） is a molecular sieve with MFI topological structure, in which small numbers of tetrahedral Si atoms are substituted by Ti atoms in a purely siliceous framework. TS-1 can catalyze numbers of selective oxidation reactions of organic reactants with H2O2 as oxidant and possess remarkable activity and selectivity for partial hydrocarbon oxidation.TS-1 has been used as a highly-efficient heterogeneous catalyst for selective oxidation of industrially important organic compounds. If active site of Ti species can be dispersed in the surface, the influence on the diffusion may be decreased. The ST-1 with enriched Ti species on its surface was prepared and characterized by means of XRD, XRF, SEM, TEM, FT-IR. As shown from the characterization by instruments, the Ti species in ST-1 with enriched mainly on its surface, not in the center of ST-1, and other physicochemical analogue to that of routine ST-1. The results of catalytic reaction indicated that Ti species were properties were induction period was shortened sharply, and is applicable in industry potentially.