Fabrication of Pd Nanoparticles Embedded C@Fe₃O₄ Core–Shell Hybrid Nanospheres: An Efficient Catalyst for Cyanation in Aryl Halides

Isolated chemical reactors were fabricated by integrating catalytically active sites (Pd) with magnetic functionality (Fe3O4) along with carbon while preserving the constituents functional properties to realize the structure-property relationship of Pd by comparing the catalytic activity of spherical Pd NPs with cubical Pd NPs for cyanation in aryl halides using K4[Fe(CN)6] as a green cyanating agent to yield corresponding nitriles. The superior catalytic reactivity of the cubical Pd NPs is attributed to the larger number of {100} surface facets. The TEM images of reused catalyst shows the change in structure from cubical to spherical nanoparticles, attributed to the efficient leaching susceptibility of Pd {100} surface facets. The cubical Pd NPs on carbon@Fe3O4 is attractive in view of its high catalytic efficiency, easy synthesis, magnetic separability, environmental friendliness, high stability, gram scale applicability, and reusability.