Effect of Bases on Catalytic Properties of Cobalt-Nitrogen-Carbon Composites in Oxidative Esterification of Benzyl Alcohol with Methanol

The specific features of the low-temperature (60°C) oxidative esterification reaction of benzyl alcohol with methanol on cobalt-nitrogen-carbon heterogeneous catalyst produced by carbonization of a ZIF-67 metal-organic framework structure were examined. The optimal temperature range of pyrolysis for preparing high-activity catalyst samples was determined. The influence of bases, e.g., K₂CO₃, Na₂CO₃, triethylamine, para-dimethylaminopyridine, and other additives on the rate and selectivity of the catalytic reaction was investigated. The results showed that esterification occurs via the intermediate formation of benzaldehyde, which is rapidly transformed to methyl benzoate in the presence of a base. Specifically, to obtain a strong catalytic effect, it is sufficient to use it in amount of 5 mol.% relative to benzyl alcohol.Nitrogen bases, including paradimethylaminopyridine, are ineffective in the co-catalysis of the reaction. Potassium compounds exert the strongest promoting infl uence among the mineral basses studied.