Hydrogen Adsorption Properties of Carbon Nanotubes and Platinum Nanoparticles from a New Ammonium-Ethylimidazolium Chloroplatinate Salt

Self-supporting membranes built entirely of carbon nanotubes have been prepared by wet methods and characterized by Raman spectroscopy. The membranes are used as supports for the electrodeposition of Pt nanoparticles without the use of additional additives and/or stabilizers. The Pt precursor is an ad hoc synthesized ammonium-ethylimidazolium chloroplatinate(IV) salt, [NH3(CH2)2MIM)][PtCl6]. The Pt complex was characterized using NMR spectroscopy, XRD, ESI-MS, and FTIR spectroscopy. The interaction between the Pt-carbon nanotubes nanocomposites and hydrogen is analyzed using electrochemical and quartz microbalance measurements under near-ambient conditions. The contribution of the Pt phase to the hydrogen adsorption on nanotube is found and explained by a kinetic model that takes into account a spillover event. Such a phenomenon may be exploited conveniently for catalysis and electrocatalysis applications in which the hybrid systems could act as a hydrogen transfer agent in specific hydrogenation reactions. Adsorption advantage: Self-supporting membranes of carbon nanotubes are prepared and used as supports for the electrodeposition of Pt nanoparticles by using an ad hoc synthetized ammonium-ethylimidazolium chloroplatinate(IV) salt as Pt precursor. The hydrogen adsorption on Pt-carbon nanotubes nanocomposites is studied experimentally by electrochemical and quartz microbalance measurements and explained by a kinetic model that takes into account a spillover event.