The use of poly(vinyl phosphonic acid) microgels for the preparation of inherently magnetic Co metal catalyst particles in hydrogen production

ŞAHİNER N., SAGBAS S.

JOURNAL OF POWER SOURCES, vol.246, pp.55-62, 2014 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 246
  • Publication Date: 2014
  • Doi Number: 10.1016/j.jpowsour.2013.07.043
  • Journal Name: JOURNAL OF POWER SOURCES
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.55-62
  • Keywords: Hydrogel-composite, Porous poly(vinyl phosphonic acid) microgel reactors, Nanogel composites, Hydrogen production, NI NANOPARTICLE PREPARATION, SODIUM-BOROHYDRIDE, GENERATION, HYDROLYSIS, NANOCOMPOSITE, NANOGELS, NICKEL, COBALT
  • Çanakkale Onsekiz Mart University Affiliated: No

Abstract

Novel poly(vinyl phosphonic acid) (p(VPA)) micro particle and composite p(VPA)-silica micro particle hydrogels are synthesized using a micro-emulsion polymerization technique. Porous p(VPA) particles are generated after removal of silica particles upon treatment of composite p(VPA) with 0.5 M NaOH solution. Bare, composite with silica, and porous p(VPA) micro particle hydrogels are used as templates and as reactors. Metal nanoparticles, Co, Ni, and Cu are generated in situ inside these hydrogels by chemical reduction of the absorbed metal ions with a reducing agent such as sodium boron hydride (NaBH4), and are used as catalyst in hydrogen production by hydrolysis of NaBH4 in a basic medium and ammonia borane (AB). The effects of reloaded metal ions, the reaction temperature, the porosity, the reusability, and the type of metal (Co, Ni, Cu) are investigated. The activation energy for hydrolysis of NaBH4, and AB by p(VPA)-Co is 28.02 and 25.51 kJ mol(-1), respectively. The mass susceptibility measurements of composite p(VPA)-Co microgel is found as ferromagnetic. It is found that p(VPA) microgels provided better catalytic performance in comparison to macro p(VPA) hydrogels due to improved properties such as higher surface area, pore structure, and inherently magnetic behavior after multiple loadings-reduction of Co(II) from aqueous medium. (C) 2013 Elsevier B.V. All rights reserved.