Magnetically recoverable trimetallic CuCoFe nanoparticles supported on N-doped carbon derived from ZIF-67 as efficient catalysts for the C–N coupling and Biginelli reactions

Trimetallic copper-cobalt-iron nanoparticles supported on nitrogen-doped carbon (CuCoFe@N–C) were synthesized via the pyrolysis of Cu dopped ZIF-67/Fe3O4 composites, producing a magnetically recoverable catalyst with hierarchical micro and mesoporous structure. This work advances MOF-derived trimetallic catalysts by addressing key limitations of prior systems, such as poor metal dispersion and instability, through ZIF-67’s structural precision and Fe3O4’s dual role as a Fe precursor and magnetic support. Comprehensive characterization using FT-IR, XRD, BET, EDX, TGA, VSM, FE-SEM, TEM, ICP-OES, and XPS confirmed a robust N-doped carbon matrix with well-dispersed Cu, Co, and Fe active sites. CuCoFe@N–C exhibited exceptional catalytic performance in Ullmann C–N coupling (up to 94% yield, 110 °C, 12 h) and Biginelli multicomponent reactions (up to 95% yield, reflux, 30 min), surpassing monometallic (Cu@N–C, Co@N–C) and bimetallic analogs (CuCo@N–C, CoFe@N–C) due to synergistic metal interactions and hierarchical porosity enabling substrate accessibility. The catalyst maintained over 90% activity after five cycles with negligible metal leaching (< 0.5 ppm) as verified by ICP-OES and leaching tests, outperforming conventional trimetallic catalysts in stability and recyclability. This work highlights a straightforward and highly efficient approach to designing MOF-derived trimetallic catalysts for impactful, recyclable chemical transformations.