Dual catalytic function of the task-specific ionic liquid: Green oxidation of cyclohexene to adipic acid using 30% H2O2

The sole industrial process which currently used for adipic acid production is nitric acid oxidation of either cyclohexanol or cyclohexanol/cyclohexanone mixture. Emission of greenhouse nitrous oxide (N2O) gas from this process strongly contributes to global warming, resulting in acid rain and ozone depletion. Herein, we report a catalytic application of a novel dual task-specific ionic liquid (an ionic liquid with two catalytic functions) for oxidation of cyclohexene to adipic acid using 30% hydrogen peroxide. The catalyst showed desirable activity toward oxidation of cyclohexene and some cyclic olefins to produce their corresponding dicarboxylic acids.

Graphical abstractFigure optionsDownload full-size imageDownload as PowerPoint slideHighlights► We synthesized a novel ionic liquid with two catalytic functions. ► This dual task-specific ionic liquid provides WO42- and –SO3H species. ► The catalyst is efficient for oxidation of cyclohexene to adipic acid.