Green Synthesis and Characterization of Zeolite X-Palladium Nanoparticles as a Suitable Catalyst for Suzuki Coupling Reaction

Zeolites are nanoporous crystalline materials with a uniform pore size distribution on a molecular scale and with high thermal, mechanical and chemical stability [1]. Zeolites have shown their potential for several emerging applications, with exciting examples appeared in the field of heterogeneous catalysis, ion-exchange, adsorptive separation, storage and biomedical-related applications. Ultrasonic wave is a type of mechanical energy, distinguished by vibrations with a frequency greater than 20 kHz. When the ultrasonic wave interacts with a liquid, local high pressures and high temperatures are generated. There are many reports about the use of ultrasound as source energy in the synthesis of micrometer sized molecular sieves [2]. The palladium-catalyzed Suzuki coupling reaction between an aryl halide and a phenylboronic acid has been among the most powerful tools for constructing C-S, C-N and C-C bonds in organic synthesis [3]. Because biaryl moieties are used as the building block of a wide range of pharmaceuticals, herbicides, natural products, polymers, and etc [4]. In this study, a simple and green energy method, sonochemical, was applied to synthesis of zeolite X-palladium nanoparticles. The advantages of this method are applying green energy, short time synthesis, and creating regular zeolite. The structure and properties of zeolite X-palladium nanoparticles were characterized by various techniques. To investigate the performance of zeolite X-palladium nanoparticles, it was used in Suzuki coupling reaction as catalyst. The zeolite X-palladium nanoparticles showed high activity in carbon-carbon coupling reaction, and, interestingly, fluorobenzene could react with phenylboronic acid in presence of this catalyst.