Magnetically separable rhodium nanoparticles as catalysts for releasing hydrogen from the hydrolysis of ammonia borane

2019-10-01
Tonbul, Yalcin
Akbayrak, Serdar
Özkar, Saim
Magnetically separable catalysts attract considerable attention in catalysis due to their facile separation from the reaction medium. This propensity is crucial for efficient multiple use of precious noble metal nanoparticles in catalysis. In fact, the isolation of catalysts from the reaction medium by filtration and washing results usually in the loss of huge amount of activity in the subsequent run of catalysis. Although many transition metal nanoparticle catalysts have been reported for the H-2 generation from the hydrolysis of ammonia borane, there is no study reporting the magnetically separable rhodium based catalysts for the hydrolytic dehydrogenation of ammonia borane. Here, we report the preparation of rhodium(0) nanoparticles supported on the surface of Fe3O4 and CoFe2O4 magnetic nanopowders as the first example of magnetically separable rhodium nanocatalysts. The resulting magnetically separable Rh-0/Fe3O4 and Rh-0/CoFe2O4 nanoparticles are highly active, long-lived and reusable catalysts in H-2 generation from the hydrolysis of ammonia borane providing a turnover frequency value of 273 and 720 min(-1), respectively, at 25.0 +/- 0.1 degrees C. These magnetically separable catalysts show high reusability and long-term stability in the hydrolysis reaction. They retain their complete initial activity even after the 5th use releasing exactly 3.0 equivalent H-2 gas per mole of ammonia borane. The long-term stability tests show that Rh-0/Fe3O4 and Rh-0/CoFe2O4 nanoparticles provide a total turnover number of 125,000 and 245,000, respectively, in releasing H-2 from the hydrolysis of ammonia borane at room temperature. The long term stability and reusability of magnetically separable Rh-0/Fe3O4 and Rh-0/CoFe2O4 nanopartides make them attractive catalysts for hydrogen generation in fuel cell applications.
JOURNAL OF COLLOID AND INTERFACE SCIENCE

Suggestions

Voltammetric and drift spectroscopy investigation in dithiophosphinate-chalcopyrite system
Guler, T; Hicyilmaz, C; Gokagac, G; Ekmekci, Z (Elsevier BV, 2004-11-01)
The mechanism of dithiophosphinate (DTPI) adsorption on chalcopyrite was investigated by diffuse reflectance Fourier transformation (DRIFT) spectroscopy and by cyclic voltammetry (CV) at various pHs. CV experiments showed that the redox reactions occurred at a certain degree of irreversibility on the chalcopyrite surface in the absence of a collector due to preferential dissolution of iron ions in slightly acid solution and irreversible surface coverage by iron oxyhydroxides in neutral and alkaline solution...
Nanozirconia supported ruthenium(0) nanoparticles: Highly active and reusable catalyst in hydrolytic dehydrogenation of ammonia borane
Tonbul, Yalcin; AKBAYRAK, SERDAR; Özkar, Saim (Elsevier BV, 2018-03-01)
Nanozirconia supported ruthenium(0) nanoparticles (Ru-0/ZrO2) were prepared by impregnation of ruthenium(III) cations on the surface of zirconia followed by their reduction with sodium borohydride at room temperature. Ru-0/ZrO2 was isolated from the reaction solution by centrifugation and characterized by ICP-OES, XRD, TEM, SEM EDS and XPS techniques. All the results reveal that ruthenium(0) nanoparticles were successfully supported on zirconia and the resulting Ru-0/ZrO2 is a highly active and reusable cat...
Electrosynthesis of polyfuran in acetonitrile-boron trifluoride-ethyl ether mixture and its device application
Tirkeş, Süha; Önal, Ahmet Muhtar (Wiley, 2007-01-15)
Electrochemical polymerization of furan was achieved in acetonitrile/boron trifluoride/ethyl ether (CH3 CN/BF3/EE) mixture in the presence of tetrabutylammonium tetrafluoroborate via constant potential electrolysis at 1.4 V versus Ag/AgCl. Electrochemical behavior of furan was investigated in the same solvent mixture of varying ratios, utilizing cyclic voltammetry. Free-standing polyfuran (PFu) films were obtained in CH3CN/BF3/EE mixture (2/4/4; v/v/v) and characterized using FTIR spectroscopic technique. S...
Electrochemical polymerization of 9-fluorenecarboxylic acid and its electrochromic device application
Bezgin, Buket; CİHANER, ATİLLA; Önal, Ahmet Muhtar (Elsevier BV, 2008-09-01)
Poly(9-fluorenecarboxylic acid) (PFCA) was synthesized by electrochemical oxidation of 9-fluorenecarboxylic acid (FCA) using a mixture of nitromethane and boron trifluoride diethyl etherate as the solvent and tetrabutylammonium tetrafluoroborate as the supporting electrolyte. An insoluble and conducting brownish-orange film was deposited on the electrode surface, both during repetitive cycling and constant potential electrolysis at 1.15 V. Characterization of the polymer film has been carried out using Four...
NH3 and H2S adsorption on Au3Pt3 cluster studied by a first principles calculation
Akturk, Olcay Uzengi; Tomak, Mehmet (Elsevier BV, 2010-07-01)
The equilibrium atomic structures of the Au3Pt3 cluster and NH3, H2S molecules are determined by Density Functional Theory calculations. The adsorption of NH3 and H2S molecules on Au3Pt3 cluster is then studied. The energy levels and the corresponding charge densities, adsorption energies, charge transfer and magnetization are calculated for different adsorption sites. We find that the adsorption generally modifies the structure of the Au3Pt3 cluster and the adsorbate. There exists strong interaction betwee...
Citation Formats
Y. Tonbul, S. Akbayrak, and S. Özkar, “Magnetically separable rhodium nanoparticles as catalysts for releasing hydrogen from the hydrolysis of ammonia borane,” JOURNAL OF COLLOID AND INTERFACE SCIENCE, pp. 581–587, 2019, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/44621.