Papers by Keyword: NaBH₄

Abstract: The result of burning hydrogen which is environmentally friendly makes hydrogen as a very attractive fuel. Hydrogen storage is interesting research material. One alternative to hydrogen storage is a metal-hydride as NaBH₄. In this paper, the catalyst for hydrogen production from storage, namely The result of burning hydrogen, which is environmentally friendly, makes hydrogen a desirable fuel. Hydrogen storage is exciting research material. One alternative to hydrogen storage is a metal-hydride as NaBH₄. In this paper, the catalyst for hydrogen production from storage, namely NaBH₄, was synthesized by electrochemical. Ni-B catalyst with hydroxyapatite as catalyst support was prepared by electrochemical. Ni-B/HA catalyst was synthesized at various current densities (namely 67, 133, and 200 mA/cm²) and various electrolysis times (namely 30, 60, and 90 minutes). The resulting catalysts were analyzed by XRD and used as the catalyst for hydrogen production from the hydrolysis reaction of NaBH₄. The fastest hydrogen production was obtained using a catalyst generated at 133 mA/cm² and an electrolysis time of 60 minutes. The reaction rate equation for the hydrolysis of NaBH₄ has a first-order reaction to the concentration of NaBH₄. The resulting reaction rate constant ranged from 233.33 mL/g/min to 861.11 mL/g/min. The relationship between reaction temperature and reaction rate constant can be expressed by the equation k = 2.2x10⁶exp (5534/T).

Abstract: The aldehydes and ketones can be reduced readily by NaBH4 without any modification. NaBH4 can not reduce esters and their derivatives under ambient conditions, reflux and standing overn ight are necessary. However, the activity of NaBH4 can be enhanced by CeCl3.7H2O. In this article, a general, highly efficient and mild methodology for obtaining alcohol compounds by reduction of the corresponding esters with NaBH4 in the presence of a catalytic amount of CeCl3.7H2O in water is described.

Abstract: Magnetic nickel nanoparticles are prepared by NaBH₄ reducing agent in AOT reverse microemulsion, the influence of water content on the morphology and magnetic properties of nickel nanoparticles are investigated by TEM study, size distribution, XRD characterization and magnetization curves. The results show that spherical and polydispered particles are obtained in microemulsion. The dimension and polydispersity of particles increased with the increasing of water content. Magnetization curves clearly indicate a ferromagnetic behavior with high coercivity values. At water content of W₀=41.7, the product has a high saturated magnetization 70.68 emu/g with its residual magnetizations 28.02 emu/g, higher than the sample obtained at water content of W₀=13.9.

Abstract: Interest in hydrogen as a future energy carrier in mobile applications has led to a strong increase in research on the structural properties of complex alkali metal and alkaline earth hydrides, with the aim to find structural phases with higher hydrogen densities. This contribution reviews recent work on the structural properties and phase diagrams of these complex hydrides under elevated pressures, an area where rapid progress has been made over the last few years. The materials discussed in greatest detail are LiAlH4, NaAlH4, Li3AlH6, Na3AlH6, LiBH4, NaBH4, and KBH4. All of these have been studied under high pressure by various methods such as X-ray or neutron scattering, Raman spectroscopy, differential thermal analysis or thermal conductivity measurements in order to find information on their structural phase diagrams. Based mainly on experimental studies, preliminary or partial phase diagrams are also given for six of these materials. In addition to this information, data are provided also on experimental results for a number of other complex hydrides, and theoretical predictions of new phases and structures under high pressures are reviewed for several materials not yet studied experimentally under high pressure.