Synthesis of a novel palladium nano-catalyst supported on Zn-Al layered double hydroxide containing schiff base and investigation of its catalytic activity.

In this study, a newly nanocatalyst with an economical, environmental, moisture and air-stable features was developed through immobilization of palladium nanoparticles on Schiff base-functionalized Zn-Al layered double hydroxide. The structure of nanocatalyst which was named Pd NPs@ZnAl LDH-Sch was fully studied by several techniques including FT-IR, TEM, EDS, FE-SEM, XPS, TG and, XRD. The catalytic potential of Pd NPs@ZnAl LDH-Sch nanocatalyst was then evaluated in the aryl halides cyanations for the fabrication of various benzonitriles using K4[Fe(CN)6]. These tests indicated that Pd NPs@ZnAl LDH-Sch nanocatalyst was tolerant against various functional groups, and the desired benzonitrile products were acquired with good to high yields within 2 h. Leaching test revealed that Pd NPs@ZnAl LDH-Sch acts heterogeneously in the reactions. Because of its heterogeneous manner, Pd NPs@ZnAl LDH-Sch was readily recovered via simple filtration and reused up to 11 successive runs by protecting its stability/durability. Moreover, it was found that the synthesized Pd NPs@ZnAl LDH-Sch nanocatalyst shows a better performance in the aryl halide cyanations than other reported catalysts.