Development of a polymer resin immobilized catalysts for the oxidative transformation of ethylbenzene

New copper, manganese and vanadium based heterogeneous catalysts have been developed by the immobilization of pyridyl benzimidazole onto the polymer support. The active catalysts were characterized using CHN, FT-IR, DRS, EPR, AAS and EDX techniques and successfully used for the oxidative transformation of ethyl benzene. Metal loading in mmol per gram of resin in different catalysts was found to be 0.94-1.34. The catalytic potential of the synthesized catalysts was evaluated for the oxidation of ethylbenzene using hydrogen peroxide and tert-butyl hydroperoxide as oxidant with undiminished efficiency profiles and good reusability (up to four cycles). Notably, no metal contamination in the final products was observed. The comparative evaluation revealed that the highest percentage conversion (82.8 %) and highest selectivity (82.5) for benzaldehyde formation was attained with manganese as catalyst using H2O2 as an oxidant. The mechanism of the oxidation of ethylbenzene in the presence of catalyst has also been proposed. The developed catalytic systems are operationally simple and environmentally clean.