Catalytic reduction of 4-nitrophenol to 4-aminophenol using an efficient Pd nanoparticles

Abstract

Highly stable catalytically active polyvinyl alcohol supported Pd nanoparticles (Pd NPs) are synthesized and used as catalysts in reduction of 4-nitrophenol in aqueous phase by sodium borohydride as reducing agent. The as—synthesized Pd NPs are characterized with the help of UV—vis. absorption spectroscopy, X—ray diffraction (XRD), transmission electron microscopy (TEM). The TEM and high resolution TEM images reveal that the synthesized Pd NPs are mostly global shaped with mean radius of c.a. 2.1 nm. The progress of the reaction is conveniently monitored by UV—vis. spectroscopy. The rate constant of the pseudo—first—order reaction increases with temperature up to 318 K. The rate constant and the activation energy for the reduction of 4-nitrophenol by using Pd nanoparticles were found as 0.013 s−1 and 14.12 kJ mol−1 respectively at 318 K. The as-prepared Pd NPs are stable, easy to prepare, cost effective and have significant efficiency for reduction of 4—nitrophenol in green protocol.