Design and synthesis of Ni3ZnC0.7 catalyst derived from a bimetallic Ni/Zn metal-organic frameworks for efficient synthesis of 2-arylbenzimidazole

Abstract

Developing efficient bimetallic Ni/Zn metal organic frameworks (MOFs) derived Ni3ZnC0.7 alloy catalyst for cyclization reactions is highly anticipated. Bimetallic Ni/Zn-PTA MOFs with flower-like microspheres morphology was synthesized by using a facile hydrothermal method and used as a precursor for preparation of the catalyst. Then, a ZnO supported Ni-Ni3ZnC0.7 incorporated carbon catalyst (Ni-Ni3ZnC0.7/ZnO-C) was obtained by deriving from the Ni/Zn-PTA MOFs through one-step pyrolysis. The developed Ni-Ni3ZnC0.7/ZnO-C catalyst was used as a recoverable heterogeneous catalyst for synthesis of 2-arylbenzimidazoles by cyclization reaction of phenylmethanamines and 2-nitroanilines in good yields. Various characterizations (e.g. SEM/EDX, XRD, TEM, FT-IR, XPS and Raman) revealed that the catalyst exhibited good performance for cyclization reaction, which are ascribed to particular hierarchical structure, as well as synergistic effect between Ni and Ni3ZnC0.7. As a result, the Ni-Ni3ZnC0.7/ZnO-C catalyst showed excellent stability and activity for the condensation cyclization reaction. This bimetallic MOFs-derived Ni-Ni3ZnC0.7 catalyst opens up a potential way for fabricating other Carbon supported alloy catalysts in heterogeneous catalysis reactions.