Monodisperse nickel nanoparticles supported on SiO2 as an effective catalyst for the hydrolysis of ammonia-borane

Metin, Onder
Özkar, Saim
Sun, Shouheng
Monodisperse Ni nanoparticles (NPs) have been synthesized by the reduction of nickel(II) acetylacetonate with the borane-tributylamine complex in a mixture of oleylamine and oleic acid. These Ni NPs are an active catalyst for the hydrolysis of the ammonia-borane (AB, H3N center dot BH3) complex under ambient conditions and their activities are dependent on the chemical nature of the oxide support that they were deposited on. Among various oxides (SiO2, Al2O3, and CeO2) tested, SiO2 was found to enhance Ni NP catalytic activity due to the etching of the 3.2 nm Ni NPs giving Ni(II) ions and the subsequent reduction of Ni(II) that led to the formation of 1.6 nm Ni NPs on the SiO2 surface. The kinetics of the hydrolysis of AB catalyzed by Ni/SiO2 was shown to be dependent on catalyst and substrate concentration as well as temperature. The Ni/SiO2 catalyst has a turnover frequency (TOF) of 13.2 mol H-2 center dot(mol Ni)(-1) center dot min(-1)-the best ever reported for the hydrolysis of AB using a nickel catalyst, an activation energy of 34 kJ/mol +/- 2 kJ/mol and a total turnover number of 15,400 in the hydrolysis of AB. It is a promising candidate to replace noble metals for catalyzing AB hydrolysis and for hydrogen generation under ambient conditions.


Monodisperse Nickel Nanoparticles; and Their Catalysis in Hydrolytic Dehydrogenation of Ammonia Borane
Metin, Onder; Mazumder, Vismadeb; Özkar, Saim; Sun, Shouheng (2010-02-10)
Monodisperse nickel nanoparticles are prepared from the reduction of Ni(acac)(2) with borane tributylamine in the presence of oleylamine and oleic acid. Without any special treatment to remove the surfactants, the as-synthesized Ni nanoparticles supported on the Ketjen carbon support exhibit high catalytic activity in hydrogen generation from the hydrolysis of the ammonia-borane (H3NBH3) complex with a total turnover frequency value of 8.8 mol of H-2 center dot(mol of Ni)(-1).min(-1). Such catalysis based o...
Palladium(0) nanoparticles supported on silica-coated cobalt ferrite: A highly active, magnetically isolable and reusable catalyst for hydrolytic dehydrogenation of ammonia borane
Akbayrak, Serdar; KAYA, MURAT; Volkan, Mürvet; Özkar, Saim (Elsevier BV, 2014-04-05)
Palladium(0) nanoparticles supported on silica-coated cobalt ferrite (Pd(0)/SiO2-CoFe2O4) were in situ generated during the hydrolysis of ammonia borane, isolated from the reaction solution by using a permanent magnet and characterized by ICP-OES, XRD, TEM, TEM-EDX, XPS and the N-2 adsorption-desorption techniques. All the results reveal that well dispersed palladium(0) nanoparticles were successfully supported on silica coated cobalt ferrite and the resulting Pd(0)/SiO2-CoFe2O4 are highly active, magnetica...
Organosilanols as Catalysts in Asymmetric Aryl Transfer Reactions
Özçubukçu, Salih; BOLM, Carsten (American Chemical Society (ACS), 2005-03-01)
Various ferrocene-based organosilanols have been synthesized in four steps starting from achiral ferrocene carboxylic acid. Applying these novel planar-chiral ferrocenes as catalysts in asymmetric phenyl transfer reactions to substituted benzaldehydes afforded products with high enantiomeric excesses. The best result (91% ee) was achieved in the addition to p-chlorobenzaldehyde with organosilanol 2b, which has a tert-butyl substituent on the oxazoline ring and an isopropyl group on the silanol fragment.
Photoinduced Electron Transfer Reactions of Highly Conjugated Thiophenes for Initiation of Cationic Polymerization and Conjugated Polymer Formation
Aydogan, Binnur; Yağcı, Yusuf; Toppare, Levent Kamil; Jockusch, Steffen; Turro, Nicholas J. (2012-10-09)
Photoinduced electron transfer reactions of highly conjugated thiophene derivatives, 4,7-di(2,3-dihydrothieno[3,4-b] [1,4]dioxin-5-yl)benzo[1,2,5]thiadiazole (DTDT) and 5,8-bis(2,3-dihydrothieno[3,4-b][1,4]dioxin-5-yl)-2,3-di(thiophen-2-yl)quinoxaline (DTDQ), with diphenyl-iodonium hexafluorophosphate (Ph2I+PF6-) and triphenylsulfonium hexafluorophosphate (Ph3S+PF6-) were investigated by laser flash photolysis, fluorescence and phosphorescence spectroscopy, and polymerization studies. High fluorescence quan...
Poly(methyl methacrylate) nanocomposites involving aromatic diboronic acid
Goktas, Muberra; Hacaloğlu, Jale (2019-12-01)
In this work, poly(methyl methacrylate), PMMA, composites involving various amounts of aromatic diboronic acid, BDBA, in the absence and presence of organically modified montmorillonite, Cloisite 30B, C30B, were prepared and characterized by X-ray diffraction, transmission electron microscopy, thermogravimetry, and direct pyrolysis mass spectrometry analyses. Morphologic analyses indicated homogenous dispersion of additives in PMMA matrix. Increase in thermal stability of PMMA was observed as the amount of ...
Citation Formats
O. Metin, S. Özkar, and S. Sun, “Monodisperse nickel nanoparticles supported on SiO2 as an effective catalyst for the hydrolysis of ammonia-borane,” NANO RESEARCH, pp. 676–684, 2010, Accessed: 00, 2021. [Online]. Available: