The catalytic evaluation of in situ grown Pd nanoparticles on the surface of Fe3O4@dextran particles in the p-nitrophenol reduction reaction

We report the catalytic activity evaluation of in situ grown Pd nanoparticles on the surface of superparamagnetic Fe3O4 particles coated with the natural polymer dextran, in the reduction of p-nitrophenol (Nip), in water, by sodium borohydride. The catalyst was fully characterized; its activity evaluated through kinetic studies and compared with recently reported catalysts using a new activity parameter. Applying a pseudo-monomolecular surface reaction approach, the reaction was also investigated by means of a theoretical adsorption model, which revealed that the reaction follows the Langmuir-Hinshelwood mechanism, where both molecules adsorb on the catalyst surface prior to undergoing a bimolecular reaction. Moreover, the catalyst could be reused five times without significant loss of Pd and with a high degree of Nip conversion.