title: Environmentally benign heterogeneous nano-particle catalysts: synthesis, characterization and catalytic activity of 4-nitrophenol.
abstract: Pollution free catalyst is an attractive area of current interest. The p-Aminophenol is one of the most significant catalyst, because it involves the manufacture of various pharmaceuticals. Crosslinked poly(styrene)-co-poly(4-vinylimidazole) (PSPVIM) was prepared by varying the crosslinked monomer ratio as 2% and 10% respectively. The 2 (w%) of DVB, 25 (w%) of N-VIm as functional monomer and 73 (w%) of styrene as support monomer as organic phase and gelatin, boric acid and polyvinyl alcohol as aqueous phase was used to prepare cross-linked poly(styrene)-co-poly(N-vinyl imidazole) (PVIM) beads (Type-I). Similarly, Type II beads were also prepared by fixing the 10% as a cross linking ratio (DVB). The immobilization of Ag NPs onto the PS-VIm polymer matrix was performed using AgNO3 as a metal precursor solution. The k(obs) determined from UV-Vis results, reveals that the degree of reduction of 4-nitrophenol using Type-I catalysts is more effective than Type-II catalyst due to lower immobilization of AgNPs at higher cross-linked bead matrix. It was found that on increasing the amount of catalyst i.e., type-I PS-PVIm-AgNPs, the rate constant also increases. Therefore, PS-PVIm-AgNPs (Type-I) heterogeneous catalyst is superior for the reduction of 4-NP.
authors.affiliation: Department of Physical Chemistry, School of Chemical Sciences, University of Madras, Chennai 600025, India.
authors.forename: Eagambaram
authors.initials: E
authors.lastname: Murugan
authors.forename: J Nimita
authors.initials: JN
authors.lastname: Jebaranjitham
mesh_terms: D002384:Catalysis; D003460:Crystallization / Q000379:methods*; D004777:Environment; D046911:Macromolecular Substances / Q000737:chemistry; D008422:Materials Testing; D008968:Molecular Conformation; D049329:Nanostructures / Q000737:chemistry* / Q000648:ultrastructure*; D036103:Nanotechnology / Q000379:methods*; D009596:Nitrophenols / Q000737:chemistry*; D010316:Particle Size; D013499:Surface Properties
chemical_list: D046911:Macromolecular Substances; D009596:Nitrophenols; C024836:4-nitrophenol