Silica embedded cobalt(0) nanoclusters: Efficient, stable and cost effective catalyst for hydrogen generation from the hydrolysis of ammonia borane

2011-09-01
Metin, Onder
Dinc, Melek
Eren, Zeynep Seda
Özkar, Saim
Show full item record
Creative Commons License
This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.
139
views
0
downloads
Cobalt(0) nanoclusters embedded in silica (Co@SiO2) were prepared by a facile two-step procedure. In the first step, the hydrogenphosphate anion (HPO42-) stabilized cobalt(0) nanoclusters were in situ generated from the reduction of cobalt(II) chloride during the hydrolysis of sodium borohydride (NaBH4) in the presence of stabilizer. Next, HPO42- anion-stabilized cobalt(0) nanoclusters were embedded in silica formed by in situ hydrolysis and condensation of tetraethylorthosilicate added as ethanol solution. Co@SiO2 can be separated from the solution by vacuum filtration and characterized by UV-Vis electronic absorption spectroscopy, TEM, SEM-EDX, ATR-IR and ICP-OES techniques. Co@SiO2 are found to be highly active and stable catalysts in the hydrolysis of ammonia borane (AB) even at low cobalt concentration and room temperature. They provide an initial turnover frequency of 13.3 min(-1) and 24,400 total turnovers over 52 h in the hydrolysis of AB at 25.0 +/- 0.5 degrees C. Moreover, Co@SiO2 retain 72% and 74% of the initial activity after ten runs recyclability and five cycles reusability test in the hydrolysis of AB, respectively. The kinetics of hydrogen generation from the hydrolysis of AB catalyzed by Co@SiO2 was studied depending on the catalyst concentration, substrate concentration, and temperature. The activation parameters of this catalytic reaction were also determined from the evaluation of the kinetic data. Copyright (C) 2011, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.
Ammonia borane, Hydrogen generation, Cobalt nanoclusters, Silica embedded, Catalyst, Hydrolysis
https://hdl.handle.net/11511/62925
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
Department of Chemistry, Article

Suggestions

Zeolite confined palladium(0) nanoclusters as effective and reusable catalyst for hydrogen generation from the hydrolysis of ammonia-borane
Rakap, Murat; Özkar, Saim (2010-02-01)
Zeolite confined palladium(0) nanoclusters were prepared by a two step procedure: incorporation of Pd2+ ions into the zeolite-Y by ion-exchange followed by the reduction of Pd2+ ions in the supercages of zeolite-Y with sodium borohydride at room temperature. Zeolite confined palladium(0) nanoclusters are stable enough to be isolated as solid materials and characterized by ICP-OES, XRD, HRTEM, SEM, X-ray photoelectron spectroscopy and N-2 adsorption technique. These nanoclusters are isolable, redispersible a...
Palladium(0) nanoparticles supported on ceria: Highly active and reusable catalyst in hydrogen generation from the hydrolysis of ammonia borane
Tonbul, Yalcin; Akbayrak, Serdar; Özkar, Saim (2016-07-13)
Palladium(0) nanoparticles supported on nanoceria (Pd-0/CeO2) were prepared by the impregnation of palladium(II) ions on the surface of ceria followed by their reduction with sodium borohydride in aqueous solution at room temperature. Pd-0/CeO2 were isolated from the reaction solution by centrifugation and characterized by ICP-OES, XRD, TEM, SEM-EDS and XPS techniques. All the results reveal that palladium(0) nanoparticles were uniformly dispersed on ceria and the resulting Pd-0/CeO2 are highly active and r...
Palladium(0) nanoparticles supported on polydopamine coated Fe3O4 as magnetically isolable, highly active and reusable catalysts for hydrolytic dehydrogenation of ammonia borane
Manna, Joydev; Akbayrak, Serdar; Özkar, Saim (2016-01-01)
Magnetic ferrite nanopowders were coated with polydopamine which is inert against the hydrolysis of ammonia borane. Coating of ferrite powders was achieved by pH-induced self-polymerization of dopamine hydrochloride at room temperature. Palladium(0) nanoparticles supported on polydopamine coated ferrite (Pd-0/PDA-Fe3O4) were prepared by impregnation of palladium(II) ions on the surface of PDA-Fe3O4 followed by their reduction with sodium borohydride in aqueous solution at room temperature. Magnetically isol...
Poly(4-styrenesulfonic acid-co-maleic acid) stabilized cobalt(0) nanoparticles: A cost-effective and magnetically recoverable catalyst in hydrogen generation from the hydrolysis of hydrazine borane
Karahan, Senem; Özkar, Saim (2015-02-09)
Herein, we report the in situ generation, isolation and characterization of cobalt(0) nanoparticles, stabilized by poly(4-styrenesulfonic acid-co-maleic acid), PSSMA, and their catalytic activity in the hydrolysis of hydrazine borane (HB). Cobalt(0) nanoparticles having average particle size of 3.1 +/- 0.5 nm were prepared by in situ reduction of cobalt(II) chloride in aqueous solution of hydrazine borane in the presence of PSSMA, isolated magnetically from the catalytic reaction solution using a magnet, an...
Nanoalumina supported palladium(0) nanoparticle catalyst for releasing H-2 from dimethylamine borane
KARABOĞA, SEDA; Özkar, Saim (2019-09-01)
Palladium(II) 2,4-pentanedionate, impregnated on alumina nanopowder, was reduced by dimethylamine borane (DMAB) forming Pd(0) nanoparticles (NPs) at room temperature. Pd(0) NPs could be isolated from solution and characterized by ATR-IR, UV-vis, XRD, SEM, TEM, XPS and BET. The results obtained from TEM images reveal the formation of palladium(0) nanoparticles on gamma-alumina, having a mean particle size of 7.1 +/- 2.6 nm. Alumina supported Pd(0) NPs with various metal loadings were employed as catalyst in ...
Citation Formats
O. Metin, M. Dinc, Z. S. Eren, and S. Özkar, “Silica embedded cobalt(0) nanoclusters: Efficient, stable and cost effective catalyst for hydrogen generation from the hydrolysis of ammonia borane,” INTERNATIONAL JOURNAL OF HYDROGEN ENERGY, pp. 11528–11535, 2011, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/62925.
METU IIS - Integrated Information Service open@metu.edu.tr