The interaction of formaldehyde molecules with Co 2+ ions in CoZSM-5 zeolites of various compositions containing various proportions between Co 2+ in exchange positions and in oxide-like clusters, as well as the transformation of formaldehyde sorbed in zeolites was followed by IR spectroscopy. The i
Base catalysis on zeolites in the formaldehyde—dimethylamine transformations
✍ Scribed by V.N. Romannikov
- Publisher
- Elsevier Science
- Year
- 1995
- Tongue
- English
- Weight
- 536 KB
- Volume
- 98
- Category
- Article
- ISSN
- 1381-1169
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✦ Synopsis
The character of catalytic transformations in the 'dimethylamine-formaldehyde-water' system was studied using ZSM-5 and Beta zeolites as catalysts, in which the concentration of strong protic centers has been varied by the chemical modification. It is shown that both the acidity of the zeolite and reaction temperature determine the direction of the transformation in the system. The decrease of these both parameters results in the growth of N,N-dimethylformamide yield, while the increase of the acidity of the zeolite and reaction temperature leads to considerable predominance of 1,3,5triazine derivative in the products. The possibility of the creation of basic catalytic sites by the weak interaction of dimethylamine molecules with low-acidic zeolite during the reaction is supposed to be a key factor, which determines the prevalent transformation route in the system.
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