Selective oxidation of styrene using zeolite encapsulated manganese complexes

Abstract

Synthesis and characterization of zeolite encapsulated manganese(III) salen complexes have been studied and these catalysts used for the aerobic oxidation of styrene. The effect of solvent, conversion, product selectivity and turnover frequency on encapsulation have been investigated. Advantageously the major irreversible catalyst deactivation could be avoided by encapsulating the catalyst active species in the super cages of zeolite X. The catalyst could be recycled after washing by a suitable solvent such as acetone. The greater stability of the encapsulated catalyst is attributed to the suppression of dimeric and other polymeric oxo complexes of Mn due to geometric constraints on their formation on encapsulation in zeolites. The formation of phenyl acetaldehyde is suppressed on encapsulation.