Jump to main content
Jump to site search

Issue 16, 2012
Previous Article Next Article

Hydrogen liberation from the hydrolytic dehydrogenation of dimethylamine–borane at room temperature by using a novel ruthenium nanocatalyst

Author affiliations

Abstract

Herein we report the discovery of an in situ generated, highly active nanocatalyst for the room temperature dehydrogenation of dimethylamine–borane in water. The new catalyst system consisting of ruthenium(0) nanoparticles stabilized by the hydrogenphosphate anion can readily and reproducibly be formed under in situ conditions from the dimethylamine–borane reduction of a ruthenium(III) precatalyst in tetrabutylammonium dihydrogenphosphate solution at 25 ± 0.1 °C. These new water dispersible ruthenium nanoparticles were characterized by using a combination of advanced analytical techniques. The results show the formation of well-dispersed ruthenium(0) nanoparticles of 2.9 ± 0.9 nm size stabilized by the hydrogenphosphate anion in aqueous solution. The resulting ruthenium(0) nanoparticles act as a highly active catalyst in the generation of 3.0 equiv. of H2 from the hydrolytic dehydrogenation of dimethylamine–borane with an initial TOF value of 500 h−1 at 25 ± 0.1 °C. Moreover, they provide exceptional catalytic lifetime (TTO = 11 600) in the same reaction at room temperature. The work reported here also includes the following results; (i) monitoring the formation kinetics of the in situ generated ruthenium nanoparticles, by using the hydrogen generation from the hydrolytic dehydrogenation of dimethylamine–borane as a catalytic reporter reaction, shows that sigmoidal kinetics of catalyst formation and concomitant dehydrogenation fits well to the two-step, slow nucleation and then autocatalytic surface growth mechanism, A → B (rate constant k1) and A + B → 2B (rate constant k2), in which A is RuCl3·3H2O and B is the growing, catalytically active Ru(0)n nanoclusters. (ii) Hg(0) poisoning coupled with activity measurements after solution infiltration demonstrates that the in situ generated ruthenium(0) nanoparticles act as a kinetically competent heterogeneous catalyst in hydrogen generation from the hydrolytic dehydrogenation of dimethylamine–borane. (iii) A compilation of kinetic data depending on the temperature and catalyst concentration is used to determine the dependency of reaction rate on catalyst concentration and the activation energy of the reaction, respectively.

Graphical abstract: Hydrogen liberation from the hydrolytic dehydrogenation of dimethylamine–borane at room temperature by using a novel ruthenium nanocatalyst

Back to tab navigation

Supplementary files

Publication details

The article was received on 06 Jan 2012, accepted on 15 Feb 2012 and first published on 15 Feb 2012


Article type: Paper
DOI: 10.1039/C2DT00042C
Citation: Dalton Trans., 2012,41, 4976-4984
  •   Request permissions

    Hydrogen liberation from the hydrolytic dehydrogenation of dimethylamine–borane at room temperature by using a novel ruthenium nanocatalyst

    S. Caliskan, M. Zahmakiran, F. Durap and S. Özkar, Dalton Trans., 2012, 41, 4976
    DOI: 10.1039/C2DT00042C

Search articles by author

Spotlight

Advertisements