Poly(2-aminoethyl methacrylate) based microgels catalyst system to be used in hydrolysis and methanolysis of NaBH4 for H2 generation

Abstract

The poly(2-aminoethyl methacrylate) (p(AEM)) microgels were synthesized by microemulsion polymerization technique and used for in situ metal nanoparticle preparation to render as p(AEM)-M (M: Co or Ni) microgel composites and were used in p(AEM) based poly ionic liquid (PIL) microgels. Next, these p(AEM)) based microgel materials were used as catalysts for hydrogen (H2) production from both hydrolysis and methanolysis reactions of sodium borohydride (NaBH4). It was found that the catalytic hydrolysis of the NaBH4 reaction, catalyzed by p(AEM)-Co microgel composite was completed in 140 min, whereas the methanolysis of NaBH4 methanolysis catalyzed by the PIL of p(AEM)+Cl− microgels was completed in 5 min both with 250 ± 2 mL H2 production. Furthermore, p(AEM)-Co microgel composite catalysts maintained 80% catalytic activity after 5 consecutive uses in NaBH4 hydrolysis. On the other hand, p(AEM)+Cl− microgels were found to afford more than 50% catalytic activity even after 20 repetitive use in NaBH4 methanolysis due to superior regeneration ability. Moreover, activation energy values for p(AEM)-Co microgel composites catalyzed NaBH4 hydrolysis reaction were calculated as 38.9 kJ/mol in comparison to 37.3 kJ/mol activation energy of p(AEM)+Cl− microgel catalyzed methanolysis reaction.