In order to investigate the rules on preparation of titanium silicalite （TS-1） the ^1H →^13C CP/ MAS NMR spectrometers were applied to track the function of template TPAOH in the process of crystallization of titan...In order to investigate the rules on preparation of titanium silicalite （TS-1） the ^1H →^13C CP/ MAS NMR spectrometers were applied to track the function of template TPAOH in the process of crystallization of titanium silicalite. The research results revealed that at the initial stage of crystallization the TPA＋ ions acting as the template could predominantly absorb the polymers of negatively charged silicatitania sol and the interactions between silica sol and titania sol could gradually lead to the formation of tiny crystal nuclei that could slowly grow up to form molecular sieves. Upon investigating the course of crystallization of titanium silicalite the ^1H →^13C CP/MAS NMR spectrometers were applied to effectively enhance the resolution of 29Si signals in the titanium silicalite. Study results have shown that during the formation of tiny crystal nuclei upon interaction between titania sol and silica sol the influence of titania sol on the silica sol was insignificant. However, when tiny crystal nuclei broke out into molecular sieves the titania sol could enter the zeolite framework that could apparently impose an enhanced effect on the silica sol.展开更多
In order to investigate the rules on formation of zeolite during crystallization of titanium silicalite zeolite (TS-1) the X-ray diffractometry and Foulier transform infra-red spectrometry were applied to track the pr...In order to investigate the rules on formation of zeolite during crystallization of titanium silicalite zeolite (TS-1) the X-ray diffractometry and Foulier transform infra-red spectrometry were applied to track the process of crystallization of titanium silicalite zeolite. The research results revealed that at the initial stage of crystallization the interactions between silica gel and titania gel in the polymer blend could gradually lead to the formation of tiny crystal nuclei with complicated structure that could slowly grow up to form molecular sieves. Quite different from the conventional zeolites that use the acid sites as the catalytically active centers, the oxidative reactivity of the titanium silicalite zeolite was not proportional to its crystallinity and is associated with the oxidative centers of titanium contained in the zeolite.展开更多
文摘In order to investigate the rules on preparation of titanium silicalite （TS-1） the ^1H →^13C CP/ MAS NMR spectrometers were applied to track the function of template TPAOH in the process of crystallization of titanium silicalite. The research results revealed that at the initial stage of crystallization the TPA＋ ions acting as the template could predominantly absorb the polymers of negatively charged silicatitania sol and the interactions between silica sol and titania sol could gradually lead to the formation of tiny crystal nuclei that could slowly grow up to form molecular sieves. Upon investigating the course of crystallization of titanium silicalite the ^1H →^13C CP/MAS NMR spectrometers were applied to effectively enhance the resolution of 29Si signals in the titanium silicalite. Study results have shown that during the formation of tiny crystal nuclei upon interaction between titania sol and silica sol the influence of titania sol on the silica sol was insignificant. However, when tiny crystal nuclei broke out into molecular sieves the titania sol could enter the zeolite framework that could apparently impose an enhanced effect on the silica sol.
基金supported by the NationalScience Foundation of China(2006CB202508)wewould like to extend our heartfelt thanks to the RIPP’s labo-ratories engaging in XRD and FT-IR analyses for theirenergetical support and warm assistance provided to thisresearch work.
文摘In order to investigate the rules on formation of zeolite during crystallization of titanium silicalite zeolite (TS-1) the X-ray diffractometry and Foulier transform infra-red spectrometry were applied to track the process of crystallization of titanium silicalite zeolite. The research results revealed that at the initial stage of crystallization the interactions between silica gel and titania gel in the polymer blend could gradually lead to the formation of tiny crystal nuclei with complicated structure that could slowly grow up to form molecular sieves. Quite different from the conventional zeolites that use the acid sites as the catalytically active centers, the oxidative reactivity of the titanium silicalite zeolite was not proportional to its crystallinity and is associated with the oxidative centers of titanium contained in the zeolite.
