Synthesis of ZSM-22 and Testing Its Catalytic Properties in the Ethylene Oxide Isomerization Reaction
- 2 Downloads
The influence of the key parameters of the synthesis of a TON-type zeolite (ZSM-22) with or without an organic structure-directing agent on its phase composition has been established. The optimal composition of the reaction mixture and the crystallization time of ZSM-22 in the presence of 1,6-diaminohexane under static conditions have been determined. The dynamics of the formation of an impurity ZSM-5 by cocrystallization during the synthesis with stirring has been revealed. For zeolite ZSM-22 synthesized using the template-free procedure, the most important factors affecting the crystallinity and the crystallization time are the synthesis temperature, the amount of seed, and agitation of the reaction mixture. The zeolites synthesized according to the both procedures have been examined in the reaction of isomerization of ethylene oxide to acetaldehyde. Zeolite ZSM-22 obtained without adding the template is not inferior in activity to the zeolite of the same structure prepared in the presence of 1,6-diaminohexane. Moreover, it exhibits higher selectivity of ethylene oxide conversion to acetaldehyde. The complete conversion of ethylene oxide has been observed on ZSM-22 zeolites of both types at a reaction temperature of 400°C, the selectivity of its conversion to acetaldehyde being at least 93%.
This work was performed as part of the state assignment of the Boreskov Institute of Catalysis of the Siberian Branch of the Russian Academy of Sciences.
- 3.H. Deldari, Appl. Catal., A 293, 1 (2005).Google Scholar
- 7.L. B. Young, CA Patent No. 1215082 (1986).Google Scholar
- 10.G. Kuhl, Verified Syntheses of Zeolitic Materials, Ed. by H. Robson (Elsevier, Amsterdam, 2001), 2nd Ed., p. 258.Google Scholar
- 13.D. Malish, T. Kobayashi, and T. Baba, Chem. Commun., 3303 (2007).Google Scholar
- 16.A. S. Kharitonov, V. S. Chernyavskii, L. V. Piryutko, et al., RU Patent No. 2600452 (2016).Google Scholar
- 20.J. P. Dever, K. F. George, W. C. Hoffman, and H. Soo, Ethylene Oxide, in Kirk–Othmer Encyclopedia of Chemical Technology, 5th Ed. (Wiley, New York, 2000), vol. 10, p. 639.Google Scholar