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

Caliskan, Salim
Zahmakıran, Mehmet
Özkar, Saim
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 degrees 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 H-2 from the hydrolytic dehydrogenation of dimethylamine-borane with an initial TOF value of 500 h(-1) at 25 +/- 0.1 degrees 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 k(1)) and A + B -> 2B (rate constant k(2)), in which A is RuCl3 center dot 3H(2)O 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.


Üner, Deniz; GERSTEIN, BC; KING, TS (Elsevier BV, 1994-04-01)
The interaction of hydrogen on potassium promoted catalysts prepared by both sequential and co-impregnation methods was studied by proton NMR spectroscopy. Potassium addition decreased the amounts of both hydrogen adsorbed on the metal (site blocking) and the support hydroxyl groups. No evidence for a ruthenium-mediated (through-metal) electronic interaction between potassium species and adsorbed hydrogen was found. During catalyst preparation, potassium was incorporated on the support by an exchange with t...
Hydrogen adsorption on Co2+ - and Ni2+- exchanged -US-Y and -ZSM-5. A combined sorption, DR UV–Vis, synchrotron XRD and DFT study
Sarohan, Nurkan; Özbek, Murat Oluş; Kaya, Yasemin; Abdellatief, Mahmoud; İpek Torun, Bahar (2022-08-01)
Hydrogen adsorption on Co2+and Ni2+exchanged Ultrastable-Y (US–Y) and ZSM-5 are investigated experimentally at 298K and up to 50bar as well as theoretically. The experimentally calculated initial isosteric heat of H2adsorption values are between −28 and −32kJ/mol for Ni2+-ZSM-5, -16kJ/mol for Co2+-ZSM-5, -23kJ/mol for Ni2+-US-Y and −18kJ/mol for Co2+-US-Y. Due to the optimumheat of adsorptionvalues observed on Co2+and Ni2+exchanged US-Y and ZSM-5, a reversiblevolumetricH2storage capacity of 20g H2/L is achi...
Hydrogen sulfide determination by solid surface luminescence
Eroglu, AE; Volkan, Mürvet; Bayramh, E; Ataman, Osman Yavuz; Mark, HB (1996-07-01)
In the analytical system suggested, atmospheric hydrogen sulfide reacts with the surface of a filter paper treated with aqueous cadmium chloride and yields a luminescent species whose intensity can be correlated with the analyte concentration in ambient air. It was shown that the luminescent species are CdS solid particles which were formed in a well defined size. The paper luminescence was also tried on polymeric surfaces; polyethyleneoxide, polyvinyl alcohol, ethylcellulose and carboxymethylcellulose were...
Hydrogen generation from the methanolysis of ammonia borane catalyzed by in situ generated, polymer stabilized ruthenium(0) nanoclusters
Erdogan, Huriye; Metin, Onder; Özkar, Saim (2011-07-19)
Addressed herein is the detailed study on in situ generation of poly(N-vinyl-2-pyrrolidone) (PVP) stabilized ruthenium(0) nanoclusters and their catalysis in the methanolysis of ammonia borane (AB). PVP-stabilized ruthenium(0) nanoclusters with an average particle size of 2.4 +/- 1.2 nm were generated in situ from the reduction of ruthenium(III) chloride during the methanolysis of AB in the presence of PVP at room temperature. The nanoclusters were characterized by UV-vis spectroscopy, TEM, XRD, XPS and FTI...
Hydrogen generation from the hydrolysis of hydrazine-borane catalyzed by rhodium(0) nanoparticles supported on hydroxyapatite
Celik, Derya; Karahan, Senem; Zahmakiran, Mehmet; Özkar, Saim (2012-03-01)
Herein, we report the preparation and characterization of rhodium(0) nanoparticles supported on hydroxyapatite (Ca-10(OH)(2)(PO4)(6), HAP) and their catalytic use in the hydrolysis of hydrazine-borane, which attracts recent attention as promising hydrogen storage materials. Hydroxyapatite supported rhodium(0) nanoparticles were readily prepared by the hydrazine-borane reduction of rhodium(III)-exchanged hydroxyapatite in situ during the hydrolysis of hydrazine-borane at room temperature. Characterization of...
Citation Formats
S. Caliskan, M. Zahmakıran, F. DURAP, and S. Özkar, “Hydrogen liberation from the hydrolytic dehydrogenation of dimethylamine-borane at room temperature by using a novel ruthenium nanocatalyst,” DALTON TRANSACTIONS, pp. 4976–4984, 2012, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/40642.