Liquid-phase oxidation process using titanosilicate catalysts with mordenite structure.

使用具有丝光沸石结构的钛硅酸盐催化剂的液相氧化过程。

基本信息

批准号：
07555248
负责人：
YASHIMA Tatsuaki
金额：
$ 6.4万
依托单位：
TOKYO INSTITUTE OF TECHNOLOGY
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (A)
财政年份：
1995
资助国家：
日本
起止时间：
1995 至 1997
项目状态：
已结题

项目摘要

Titanosilicate with mordenite structure was prepared by Atom-planting method using dealuminated mordenite and TiCl_4. A strong absorption at 220 nm in UV spectra indicated tetrahedral coordination of Ti species. An absorption band also appeared at 963 cm^<-1> in IR spectra. Its absorbance was in proportion to the concentration of Ti. This was an evidence of framework incorporation of all the Ti species. A TiCl_4 reacts with a defect site, hydroxyl nest, to form four Ti-O-Si bonds.Liquid-phase hydroxylation of toluene with hydrogen peroxide was carried out on titanosilicate. Cresol isomers were produced with selectivity higher than 99%. Turnover number (TON) increased with increasing hydrophobisity of catalyst by dealumination. Benzene, ethylbenzene and cumene gave almost the same TON as toluene, while TON in the hydroxylation of t-butylbenzene was much lower. On MFI-type titanosilicate, however, only benzene was reacted with the same TON ; the others showed much less reactivity. It was revealed that titanosilicate with mordenite structure is effective catalyst for the hydroxylation of large aromatic molecules compared with that with MFI structure. The framework Ti species in titanosilicate catalyzes ammoximation of ketones with ammonia and hydrogen peroxide, because absorbance of the 963 cm^<-1> IR band was in proportion to the reaction rate of ammoximation. Dealumination of the parent mordenite caused the increase in oxime selectivity as well as activity through the increase in hydrophobic nature of the catalyst.

以脱铝丝光沸石和TiCl_4为原料，采用原子注入法制备了丝光沸石结构的钛硅酸盐。紫外光谱中 220 nm 处的强吸收表明 Ti 物种的四面体配位。在IR光谱中，吸收带也出现在963cm ^ -1 处。其吸光度与Ti的浓度成正比。这是所有钛物质骨架合并的证据。 TiCl_4与缺陷位点羟基巢反应形成四个Ti-O-Si键。甲苯与过氧化氢对钛硅酸盐进行液相羟基化反应。甲酚异构体的选择性高于99%。周转数（TON）随着脱铝催化剂疏水性的增加而增加。苯、乙苯和枯烯的 TON 几乎与甲苯相同，而叔丁基苯羟基化的 TON 则低得多。然而，在 MFI 型钛硅酸盐上，只有苯与相同的 TON 发生反应；其他人的反应要少得多。结果表明，与MFI结构的钛硅酸盐相比，丝光沸石结构的钛硅酸盐是大芳香族分子羟基化的有效催化剂。钛硅酸盐中的骨架Ti物种催化酮与氨和过氧化氢的氨肟化，因为963cm ^ -1 IR波段的吸光度与氨肟化的反应速率成正比。母体丝光沸石的脱铝通过催化剂疏水性的增加导致肟选择性以及活性的增加。