Highly Basic and Dipolar Layered Double Hydroxides Enhance Catalysis of Cyanoethylation of Alcohols

Abstract

Layered double hydroxides (LDH), magnesium–aluminum–carbonates and magnesium–gallium–aluminum–carbonates, were synthesized by sol–gel incorporating during synthesis a part of aluminum as (AlF6)3− blocks in order to incorporate F− as a part of brucite-like layers and not as compensating anions. Structural, textural and surface properties of resulting fluorinated were characterized. Particularly, presence the fluorine as a part of brucite-like layers influenced directly polarity and hydrogen bonding acceptor character at surface of materials. These modifications at surface of LDH greatly changed their catalytic properties. Cyanoethylation reaction between acrylonitrile and methanol was catalyzed by both fluorine-free and fluorinated LDH, pointing out a clear influence of fluorine on the conversion and rate reaction.