Synthesis and activity evaluation of a FeCl2-promoted palladium hollow nano-sphere heterogeneous catalyst in Mizoroki–Heck coupling reactions

Abstract

A high-active, high-quality, and high-yield hollow Pd–PVP–Fe (palladium–poly(N-vinylpyrrolidone)–iron) nano-sphere catalyst with cubic structure was synthesized via a cheap method without using any support. This catalyst exhibited excellent catalytic activity in the Mizoroki–Heck reactions of less reactive chlorobenzene and some aryl bromides with n-butyl acrylate. The catalyst was fully characterized using SEM (scanning electron microscopy), EDX (energy dispersive X-ray spectroscopy), TEM (transmission electron microscopy), HRTEM (high resolution TEM), SAED (selected area electron diffraction) pattern, XRD (X-ray diffraction spectroscopy), FT-IR (Fourier transform infrared spectrophotometry), UV–Vis Spectrophotometry, Zeta sizer, and AAS (atomic absorption spectrometry). Effects of FeCl2·4H2O and PVP concentrations as well as their compatibility with palladium in the catalytic system were investigated. The catalytic property of the catalyst can be controlled by adjusting the proportion of Fe0, Pd0, and PVP concentration. The reused catalyst showed excellent activity as well as negligible leaching of the metal nanostructures into solution from the catalyst system.