Activated carbon supported Co1.5PW12O40 as efficient catalyst for the production of 1, 2 cyclohexane diol by oxidation of cyclohexene with H2O2 in the presence of CO2

Abstract

Vicinal diols are important building blocks for chemicals and pharmaceuticals. Currently, they are produced from olefins using solvents and harmful oxidants unfavorable from an environmental and economic point of view. This work lies on the synthesis of 1,2 cyclohexane diol from cyclohexene by a green route. To achieve it, a series of Cobalt Keggin heteropolyanion salt (Co1.5PW12O40) loaded on activated carbon with different contents was prepared, characterized and tested for the synthesis of diol. The effect of various parameters such as reaction temperature, reaction time and CO2 pressure on the reaction was studied. The effect of reaction temperature in the range 60-80 °C showed that high temperatures favor diol formation while low temperatures favor cyclohexanone and a segmented concave Arrhenius graph was observed. The results of this work showed that oxidation by H2O2 in the presence of CO2 is an efficient oxidant system for the production of 1.2 cyclohexane diol over carbon activated carbon supported Co1.5PW12O40. Thanks to CO2 as a soft oxidizing agent, a conversion of 96.9% and a selectivity in 1, 2 cyclohexane diol of 64.2% was obtained. This simple, safe and environmentally method could be an alternative green route for vicinal diols production from alkenes.

Keywords

• cyclohexene dihydroxylation
• carbon dioxide
• hydrogen peroxide
• polyoxometalates
• activated carbon