Fabrication of Pd NPs/Mg–Al LDH via a facile one-step hydrothermal method as highly active and stable heterogeneous catalyst for Heck coupling reaction

A facile one-step hydrothermal approach was proposed to fabricate Pd nanoparticles decorated Mg–Al layered double hydroxide nanosheets (denoted as Pd NPs/Mg–Al LDH composite), wherein polyvinylpyrrolidone (PVP) functioned as both a reductant and stabilizer. The resulting samples were characterized by XRD, SEM, TEM, XPS and BET techniques. The effect of synthetic parameters during the hydrothermal reaction including PVP dosage and temperature on the size and distribution of Pd NPs was investigated in details. Pd nanoparticles with an average particle size of 3.6 nm were uniformly supported onto Mg–Al LDH nanosheets under the optimal conditions. The obtained Pd NPs/Mg–Al LDH composite could serve as an efficient heterogeneous catalyst for the Heck reaction between iodobenzene and methyl acrylate, achieving a high yield of 95.8% within 60 min at 100 °C. Furthermore, Pd NPs/Mg–Al LDH was highly stable and reused 6 times without significant loss of its catalytic activity.