Metal nanoparticle preparation within modifiable p(4-VP) microgels and their use in hydrogen production from NaBH4 hydrolysis

Composite poly(4-vinyl pyridine)-silica (p(4-VP)-Si) nanoparticles were synthesized, employing trimethoxy vinyl silane (TMVS) as silica forming agent using ethylene glycol dimethacrylate (EGDMA) as the cross-linker, and ammonium persulfate (APS) as the initiator in an oil-in-water micro emulsion system. Porous p(4-VP) nanoparticles were generated from p(4-VP)-Si by treatment with hydrofluoric acid (HF). The size of p(4-VP)-based particles ranged between 300 and 500 nm. The porous p(4-VP) particles have a surface area of 42.26 m(2)/g. We also report preparation of various metal nanoparticles, such as Co and Ni, inside bare p(4-VP), p(4-VP)-Si and porous p(4-VP) nanoparticles by absorption from the corresponding metal ions aqueous solution and then reduction with NaBH4. Atomic Absorption Spectroscopy (AAS) was used to determine the metal particle content of the p(4-VP)-based nanoparticles. The hydrogen production rate of Co-containing p(4-VP) was found to be superior to Ni-containing p(4-VP) under the same conditions. Cobalt-containing p(4-VP)-Si and porous p(4-VP) microgel composites can generate hydrogen faster than Co-containing p(4-VP). Moreover, p(4-VP)-based microgels showed seven fold hydrogen production rate, and almost five fold turn over frequency (TOF) than p(AMPS) microgels in terms of catalytic performances reported earlier. Copyright (C) 2013, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.