Pilot Studies On Extra-large Pore Zeolite CTUT-1 With Novel Structure

The synthesis of pure-silica zeolite CTUT-1 and high-silica B-CTUT-1 using polyethylene glycol complex as template is first reported in this paper. The features as to its structure , shape, adsorption, stability are characterized by XRD, TEM, SEM, N2 adsorption, IR, TG-DTA. Results show that CTUT-1 is probably a kind of novel ultra-large pore zeolite and B-CTUT-1 possesses weak acidity. The factors such as polymerization degree of PEG, PEG concentration, crystallization time, alkali amount, water amount, silica amount, boron amount et al. are investigated and the proper phase area is obtained.Based on the crown ether -like behavior characteristics of PEG, supra molecular -templating mechanism model is established by using the modern supra molecular chemistry theory and method. The supra molecular -templating mechanism is verified by studying relations between polymerization degree and concentration of PEG and its complexation ability, IR comparison between PEG and CTUT-1 sample as well as feed order . The supra molecular -templating mechanism is applied to explain experimental phenomena.Methods such as (1) synthesis from dense solution, (2) synthesis in alcoholic systems, (3) systhesis in the presence of F ,(4) solid silicon source technique ,(5) addition of nuclearion suppressor are used to synthesize CTUT-1 large crystal. Resultes show that (3) is most effective while (2) can not produce CTUT-1 phase, which are explained by crystallization process theory combined with supra molecular -templating machanism.