Reductive amination of cyclohexanone in the presence of cyclohexanol over zeolites Hβ and HY

Reductive amination of a mixture of cyclohexanone/cyclohexanol in varying proportions has been carried out in the gas phase over zeolites Hβ and HY. The products identified were cyclohexylamine, N-cyclohexylcyclohexanimine, 2-cyclohexen-1-ylcyclohexanone and 2-cyclohexylcyclohexanone. The product distribution during the experiments indicates that cyclohexanol does not undergo reductive amination over acid catalysts; it only forms a condensation product with cyclohexanone. The reaction rates were obtained from experimental data and fit to a kinetic model derived for this reaction. The fits show that this reaction follows a Langmuir–Hinshelwood pathway by the adsorption of both cyclohexanone and the NH3 on the surface of the zeolite.

Graphical abstractReductive amination of a mixture of cyclohexanone/cyclohexanol in varying proportions has been carried out in gas phase over zeolites Hβ and HY. The product distribution during the experiments indicates that cyclohexanol does not undergo reductive amination over acid catalysts; it only forms a condensation product with cyclohexanone. Kinetic studies during the reaction show that this reaction follows a Langmuir–Hinshelwood pathway by the adsorption of both cyclohexanone and the NH3 on the surface of the zeolite. The active sites for this reaction are postulated to be the weak and moderate acid sites and not the strong acid sites on these zeolites.Figure optionsDownload full-size imageDownload high-quality image (92 K)Download as PowerPoint slide