Photocatalytic Oxidative Esterification of Benzaldehyde with the Participation of Crystalline Carbon Nitride
摘要
It has been established that crystalline carbon nitride obtained by heat treatment of g-C3N4 in molten KCl and LiCl salts exhibits photocatalytic activity in the oxidative esterification of benzaldehyde in methanol and ethanol solutions. The reaction proceeds only in the presence of palladium ions, which are reduced with the alcohols in situ, and acid, which promote benzaldehyde acetalization. A probable mechanism of the photocatalytic process is proposed, which involves the oxidation of acetal by a superoxide ion radical, the subsequent interaction of the formed acetal radical with an oxygen molecule, the formation of a tickle organic peroxide and its fragmentation according to the Russell mechanism with the formation of benzoate.