Continuous preparation of a nickel-based catalyst via membrane dispersion microreactor and its application in the hydrogenation of 4,4’-dinitrodiphenyl ether

Abstract

4,4’-Diaminodiphenyl ether (ODA) is a key monomer in the synthesis of polyimides and possesses significant application value. However, conventional synthesis methods suffer from notable shortcomings, such as reliance on expensive noble metal catalysts or the requirements for harsh reaction conditions and discontinuous preparation processes when using non-noble metal catalysts. Herein, we employed a dual-membrane micro-dispersion reactor system and low-cost hydrated sodium silicate as the silicon source to achieve green, continuous, and highly efficient synthesis of a bimetallic Ni–Co supported catalyst. The reactor enables precise microscale mixing and mass transfer control, significantly optimizing the catalyst preparation process. Structural characterization results indicated uniform dispersion of metal nanoparticles and strong interactions between the active components and the support, leading to a remarkable enhancement in catalytic performance. In the liquid-phase hydrogenation of 4,4’-dinitrodiphenyl ether (DNDPE) to ODA, the catalyst exhibited excellent activity and stability. The target product yield reached 99.25%, and no significant loss of activity was observed after five consecutive reaction cycles, demonstrating the outstanding process intensification and controllability offered by the dual-membrane micro-dispersion reactor in continuous-flow synthesis.

Graphical abstract