One-step synthesis of nitriles by the dehydrogenation–amination of fatty primary alcohols over Cu/m-ZrO2

:•Nitriles were synthesized with fatty primary alcohols and NH3 over Cu/m-ZrO2.•It is obviously influenced by the C2-substitution of fatty primary alcohols.•A substantial amount of Cu species over m-ZrO2 is in highly dispersed CuO.•Aldehyde generation is an important step in the reaction mechanism.

An effective method for one-step synthesis of nitriles employing C2–C8 fatty primary alcohols and ammonia over 5%Cu/m-ZrO2 has been found. The conversion of alcohols and selectivity of nitriles obtained are > 96 and > 87 wt.%, respectively, and are obviously influenced by the C2-substitution rather than the chain length of fatty primary alcohols. Cu/m-ZrO2 was characterized by XRD, H2-TPR, CO2-TPD and NH3-TPD. It is revealed that a substantial amount of Cu species over m-ZrO2 is in highly dispersed CuO. A plausible mechanism is proposed and supported by different experiments, and aldehyde generation is an important step in the reaction mechanism.

Graphical abstractCu/m-ZrO2 is an effective catalyst for one-step synthesis of fatty nitriles employing the C2–C8 primary fatty alcohols. Firstly, alcohols are dehydrogenated to produce corresponding aldehydes over Cu0 active site. Subsequently, the aldehydes react with ammonia rapidly to produce imines through nucleophilic addition and intermolecular dehydration. Then the imines are dehydrogenated to produce corresponding nitriles.Figure optionsDownload full-size imageDownload as PowerPoint slide