Оксид фторида алюминия (AlFO)

Description

Aluminum fluoride oxide (AlOF) is an inorganic compound of aluminum, fluorine and oxygen, gross formula AlFO, CAS 13596-12-8. It belongs to the class of aluminum fluoride-oxide materials - intermediate in composition between aluminum fluoride (AlF3) and aluminum oxide (Al2O3), combining Lewis and Brønsted acid sites, due to which the material is in demand in heterogeneous catalysis.

Basic Attributes

• CAS No: 13596-12-8
• Chemical Formula: AlFO
• English name: Aluminum fluoride oxide (AlFO)
• Molecular Weight: 61.9793412
• Exact weight: 64.9983
• EU number: 237-036-3
• DSSTox ID: DTXSID1065550
• PSA specifications: 17.1
• XLogP3: -2.7773

Scope of application

Aluminum fluoride oxide materials are produced, in particular, by the sol-gel method from aluminum alkoxides and fluorine sources, which gives controlled porosity and particle uniformity, which is in demand in industrial catalysis.

• catalyst and catalyst carrier in chlorofluorination and dehydrofluorination reactions in the production of organofluorine compounds
• acid catalyst with controlled ratio of Lewis and Brønsted sites for organic synthesis
• intermediate product during the transition from aluminum fluoride to aluminum oxide in technological processes of fluoride metallurgy
• raw materials for the production of specialized fluoride ceramics

Mechanism of action

Unlike pure aluminum oxide, where the acid sites are predominantly of the Lewis type, the replacement of some oxygen atoms with fluorine in the AlOF structure creates additional Brønsted acid sites due to the polarization of aluminum-oxygen bonds by neighboring fluorine atoms. This combination of two types of acidity increases the catalytic activity of the material in reactions that require both activation of the substrate by coordination (Lewis centers) and proton transfer (Brønsted centers) - in particular, in reactions of substitution of chlorine for fluorine in organofluorine synthesis.

Storage and transportation

Store in a dry, well-ventilated area in a tightly closed container, away from moisture - the hydrolytic instability of aluminum fluoride oxide compounds requires protecting the product from contact with atmospheric moisture at all stages of storage and transportation.

Methods of obtaining

One of the main ways to synthesize the material is through the sol-gel process: aluminum alkoxide, such as isopropoxide or sec-butoxide, is subjected to controlled hydrolysis and polycondensation in the presence of a source of fluoride ions, which makes it possible to control the pore size and particle uniformity of the finished product - parameters that directly affect its catalytic activity and selectivity in industrial processes.

Place among aluminum fluoride oxide materials

The ratio of fluorine to oxygen in the AlFO structure can be varied widely during synthesis, yielding a series of materials from almost pure alumina to compositions approaching aluminum fluoride; Each point in this series is distinguished by its balance of Lewis and Brønsted acid sites and, accordingly, by its optimal area of ​​catalytic application.