Palladium metal nanoparticles fabricated and stabilized in microgels for reduction of nitrobenzene derivatives

• Published in: Inorganic chemistry communications 2025-02, Vol.172, p.113740, Article 113740
• Main Authors: Ahmad, Hafiz Adnan, Ahmad, Rida, Begum, Robina, Sadaf, Sonia, Farooqi, Zahoor H., Guan, Zheng-Hui
• Format: Article
• Language: English
• Subjects: Catalysis; Green chemistry; Microgel; N-isopropylmethacrylamide; Nitroarenes; Pd nanoparticles
• ISSN: 1387-7003
• DOI: 10.1016/j.inoche.2024.113740

[Display omitted] •Poly(N-isopropylmethacrylamide) microgels were prepared by free radical precipitation polymerization.•Microgels were used as micro-reactors for fabrication and stabilization of Pd nanoparticles.•A variety of highly toxic nitroarenes was converted into aryl amines using hybrid microgels.•Hybrid system is recyclable and gives excellent yield of the products. Poly(N-isopropylmethacrylamide) [p(NIPMAM)] microgel particles were synthesized from N-isopropylmethacrylamide and N, N′-methylenebisacrylamide crosslinker by precipitation polymerization method. The spherical shape Pd nanoparticles with a diameter of 4–8 nm were successfully fabricated within the dispersion of the polymer framework of microgel system by the in-situ reduction of [PdCl4]-2 in aqueous medium. Both pure [p(NIPMAM)] and hybrid (Pd-[p(NIPMAM)]) microgel systems were characterized by Fourier transformed infrared spectroscopy (FTIR), Transmission electron microscopy (TEM), Energy dispersive X-ray (EDX), Thermogravimetric analysis (TGA), UV–Visible spectroscopy (UV–Vis) and X-ray diffraction (XRD), to analyze the morphology and stability of the microgel particles. The catalytic potential of the hybrid microgel system was investigated by using the reductive transformation of nitroarenes into corresponding amines. The Pd-[p(NIPMAM)] microgel system reduced a series of nitroarenes with good to excellent yield (90–97 %) under environment friendly conditions. The hybrid catalyst system was found equally efficient to transform monocyclic, bicyclic, heterocyclic and poly substituted nitroarenes into the respective amines keeping many functionalities intact. The Pd-[p(NIPMAM)] catalyst is stable under air and below 300OC. Further, it can recycle numerous times without any notable loss in its catalytic potential.