Malus domestica Mediated Synthesis of Palladium Nanoparticles and Investigation of Their Catalytic Activity Towards the Suzuki Coupling Reactions

Synthesis of nanoparticles through green methods is considered to be more eco-friendly and facile as compared to conventional physical and chemical methods. In this work, an environmental friendly method to synthesize palladium nanoparticles (Pd-NPs) by using a fruit extract has been reported. This extract obtained from Malus domestica (apple); acted as a source of reducing agent and functioned as a capping agent as well. The Pd-NPs were monitored and characterized by ultraviolet-visible (UV-Vis) spectroscopy; powder X-rays diffraction (XRD), scanning electron microscopy (SEM) and Fourier-transform infra-red (FT-IR) spectroscopy. FT-IR spectra revealed the presence of abundant amounts of ascorbic acid in the fruit extract which is assumed to reduce the Palladium chloride to Pd-NPs. XRD results confirmed the crystalline nature of Pd-NPs (JCPDS: No. 05-0681, space group: Fm3m (225)). These nanoparticles were further investigated for their catalytic activity towards the Suzuki coupling reactions where by employing only 2 mol% of the catalyst loading these Pd-NPs demonstrated excellent catalytic activity. Progress and completion of reactions were monitored by gas chromatography (GC) while products formed were characterized by gas chromatography-mass spectrometry (GC-MS), FT-IR as well as from their melting points data. Pd-NPs showed excellent catalytic activity; thereby suggesting their potential and scope for various other catalytic transformations.