Solvent‐Free Synthesized Zeolites NaA‐Supported Binary Nickel‐Silver Nanoparticles and Their Use as an Efficient Catalyst for Hydrodechlorination of 2,4‐Dichlorophenol

Abstract

Using a solvent‐free method, zeolite NaA was synthesized from raw kaolin, collected from Binh Duong, Vietnam. The synthesis involved thermal hydration under an alkaline solution. The catalysts based on binary nickel‐silver nanoparticles were prepared through in situ reduction of metal salts in aqueous zeolitic suspension using sodium borohydride as a reducing agent. The catalysts were fully characterized by various techniques such as X‐ray diffraction (XRD), Fourier transform infrared (FT‐IR), scanning electron microscopy (SEM), energy‐dispersive X‐ray (EDX), transmission electron microscopy (TEM), and Brunauer–Emmett–Teller (BET). The physicochemical properties of these catalysts were studied in detail, in which the formation of body‐centered cubic crystal zeolite NaA (1‐2 μm) containing the spherical shape of metallic nanoparticles with a particle size around 8–20 nm was observed. The hydrodechlorination of 2,4‐dichlorophenol was performed to confirm the high catalytic activity and stability of the 10%NiAg/ZA catalyst. The results showed that the catalyst achieved over 91% conversion initially and 73% conversion after five re‐uses.