Amination of Cyclohexanol over a Ni‐Based Catalyst – Part II: Catalyst Stability and Reaction Pathway

Abstract

AbstractNi‐based catalysts present a highly interesting performance for the reductive amination of cyclohexanol (CHOL). The stability of a commercial Ni‐based catalyst was evaluated and a high stability over the tested time‐on‐stream (TOS) was observed. The reaction network was evaluated by analysis of selectivity profiles as a function of CHOL conversion. The formation of cyclohexylamine (CHA) was found to be consistent with the proposed borrowing hydrogen method (BHM). The formation of heavy‐end (HE) by‐products also follows the BHM pathway as parallel reaction. The effect of individual molar proportions of NH3 and H2 was evaluated. It was found that when H2 is present in a high excess, side reactions were favored, but its presence is mandatory towards keeping the catalyst active.