Quantum-chemical investigation of mechanism of dehydroxylation of crystalline and amorphous aluminosilicates

Journal Article · Tue Jul 01 00:00:00 EDT 1986 · Kinet. Catal. (Engl. Transl.); (United States)

OSTI ID:7005316

Senchenya, I N; Chuvylkin, N D; Kazanskii, V B

Within the framework of the cluster approach and the semiempirical SCF MO LCAO method in the CNDO/BW valence approximation, possible pathways have been compared for the dehydroxylation of aluminosilicate systems. It has been shown that dehydroxylation as a result of splitting of a water molecule from an acidic bridge hydroxyl group and a more basic terminal group Al-OH is the most energyfavorable. Apparently, such a dehydroxylation pathway is primarily characteristic for amorphous aluminosilicates. Typical of crystalline aluminosilicates at moderate heat-treating temperature is dehydroxylation through splitting of a water molecule from an acidic bridge hydroxyl group and a neutral Si-OH group; at higher temperatures, there is a possible pathway of dehydroxylation of highsilica zeolites as a result of condensation of two acidic surface hydroxyls.

• Research Organization: N.D. Zelinskii Institute of Organic Chemistry, Acad. of Sci, Moscow
• OSTI ID: 7005316
• Journal Information: Kinet. Catal. (Engl. Transl.); (United States), Vol. 27:1,PT. 1
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
ALUMINIUM SILICATES
CATALYTIC EFFECTS
CHEMICAL REACTION KINETICS
HYDROXYL RADICALS
REMOVAL
BROENSTED ACIDS
CATALYSTS
ELECTRONIC STRUCTURE
LEWIS ACIDS
QUANTUM MECHANICS
SEPARATION PROCESSES
ZEOLITES
ALUMINIUM COMPOUNDS
HYDROGEN COMPOUNDS
INORGANIC ACIDS
INORGANIC ION EXCHANGERS
ION EXCHANGE MATERIALS
KINETICS
MATERIALS
MECHANICS
MINERALS
OXYGEN COMPOUNDS
RADICALS
REACTION KINETICS
SILICATES
SILICON COMPOUNDS
400201* - Chemical & Physicochemical Properties