Conversion of CH and Hydrogen Storage via Reactions with MgH-12Ni.

The main key to the future transition to a hydrogen economy society is the development of hydrogen production and storage methods. Hydrogen energy is the energy produced via the reaction of hydrogen with oxygen, producing only water as a by-product. Hydrogen energy is considered one of the potential substitutes to overcome the growing global energy demand and global warming.

Three Methods for Application of Data from a Volumetric Method to the Kissinger Equation to Obtain Activation Energy.

Thermal analysis methods have been used in many reports to determine the activation energy for hydride decomposition (dehydrogenation). In our preceding work, we showed that the dehydrogenation rate of Mg-5Ni samples obeyed the first-order law, and the Kissinger equation could thus be used to determine the activation energy. In the present work, we obtained the activation energy for dehydrogenation by applying data from a volumetric method to the Kissinger equation.

Improvement in Hydriding and Dehydriding Features of Mg-TaF-VCl Alloy by Adding Ni and x wt% MgH (x = 1, 5, and 10) Together with TaF and VCl.

In our previous work, TaF and VCl were added to Mg, leading to the preparation of samples with good hydriding and dehydriding properties. In this work, Ni was added together with TaF and VCl to increase the reaction rates with hydrogen and the hydrogen-storage capacity of Mg. The addition of Ni together with TaF and VCl improved the hydriding and dehydriding properties of the TaF and VCl-added Mg.

Study on the Variation in Microstructure of a Ferritic Stainless Steel with Surface Roughness and Thermal Cycling in Air.

A ferritic stainless steel, Crofer 22 APU, is one of candidates for metallic interconnects of solid oxide fuel cells. Ferritic stainless steel Crofer 22 APU specimens with different surface roughnesses were prepared by grinding with SiC powder papers of various grits and were then thermally cycled. Polished Crofer 22 APU specimens after one thermal cycle and five thermal cycles had relatively straight oxide layers with similar thicknesses of 30 m, suggesting that after one cycle (total oxygen exposure time of 100 h at 1073 K), the oxidation does not progress.

Development of Magnesium-Based Material with Hydrogen-Storage Capacity of 7 wt.

TiCl₃ was chosen as an additive to increase hydriding and dehydriding rates of Mg. In our previous works, we found that the optimum percentage of additives that improved the hydriding and dehydriding features of Mg was approximately ten. Specimens consisting of 90 wt% Mg and 10 wt% TiCl₃ (named Mg-10TiCl₃) were prepared by high-energy ball milling in hydrogen.

Amelioration of Hydrogen Uptake and Release Features of Magnesium Adding a Polymer Polyvinylidene Fluoride via Milling in Hydrogen in a Planetary Ball Mill.

In the present study, a polymer polyvinylidene fluoride (PVDF) was chosen as an adding material to ameliorate hydrogen uptake and release features of Mg. Samples with a composition of 95 wt.% Mg+5 wt.

Rate-Controlling Steps for the Hydriding Reaction of the Intermetallic Compound Mg₂Ni.

Mg₂Ni samples were prepared by sintering a pelletized mixture under an argon atmosphere in a stainless steel crucible at 823 K. The XRD pattern of the prepared Mg₂Ni sample showed a well crystallized Mg₂Ni phase. The hydriding and dehydriding properties of the prepared samples were examined at 518-593 K under relatively low hydrogen pressures of 3-7 bar H₂.

Increasing the Hydrogenation and Dehydrogenation Rates of Magnesium by Incorporating CMC(Na) (Carboxymethylcellulose-Sodium Salt) and Nickel.

Samples with compositions of 95 wt% Mg + 5 wt% CMC(Na) [carboxymethylcellulose, sodium salt, {CHO₂(OH)(C₂H₂O₃Na)}] [named Mg-5CMC(Na)] and 90 wt% Mg + 10 wt% CMC(Na) [named Mg-10CMC(Na)] were prepared via milling in hydrogen (hydride-forming milling). Mg-5CMC(Na) and Mg-10CMC(Na) had very high hydrogenation rates but low dehydrogenation rates. Adding Ni to Mg is known to increase the hydrogenation and dehydrogenation rates of Mg.

Hydrogenation and Dehydrogenation Behaviors of Mg₂Ni Synthesized by Sintering Pelletized Mixtures Under an Ar Atmosphere.

A Mg₂Ni intermetallic compound was synthesized by sintering under an argon atmosphere in a stainless steel crucible at 823 K. The hydrogenation and dehydrogenation features of the synthesized samples were investigated. Hydrogenation and dehydrogenation behaviors of Mg₂Ni were plotted using the Johnson-Mehl equation for the nucleation and growth mechanism.

Improvement in the Hydrogen-Storage Characteristics of Magnesium Hydride by Grinding with Sodium Alanate and Transition Metals in a Hydrogen Atmosphere.

In this work, MgH2 was used as a starting material instead of Mg. The sample was prepared by grinding MgH2 with sodium alanate and transition metals in a hydrogen atmosphere. Its hydriding and dehydriding properties were measured followed by X-ray diffraction (XRD) analyses and observations of its microstructure.

Development of an Mg-Based Alloy with High Hydriding and Dehydriding Rates and Large Hydrogen Storage Capacity by Adding TaF.

A sample with a composition of 95 wt% Mg + 5 wt% TaF5 (named Mg-5TaF5) was prepared by reactive mechanical grinding. The activation of Mg-5TaF5 was not necessary, and Mg-5TaF5 had an effective hydrogen storage capacity (the quantity of hydrogen absorbed for 60 min) larger than 5 wt%. At the first cycle (n = 1), the sample absorbed 4.

Hydrogen-Storage Properties of Ni and LiBH4-Added MgH2.

In this work, MgH2 was employed as a starting material instead of Mg used in our previous work. Ni and LiBH4, which can absorb 18.4 wt% of hydrogen, were added.

Enhancement of the Hydrogen-Storage Properties of MgH2 by the Addition of Ni, NaAlH4, Ti, and CNT via Reactive Mechanical Grinding.

MgH2 was used as the starting material in this study. A sample with the composition of 84 wt% MgH2 + 10 wt% Ni + 2 wt% NaAlH4 + 2 wt% Ti + 2 wt% CNT (named MgH2-10Ni-2NaAIH4-2Ti-2CNT) was prepared by the reactive mechanical grinding. Hydriding and dehydriding property measurements, X-ray diffraction (XRD) analyses, and microstructural observations were then performed.