Metal-hydrogen Systems Research Articles

Co-Deposited Hydrogen in Electrodeposited Pd Films: Insights from High-Temperature Thermal Desorption Spectroscopy

Palladium (Pd) has been extensively studied for hydrogen absorption and desorption as a fundamental metal of the metal-hydrogen systems. When hydrogen is absorbed into bulk Pd under high pressure or via electrolytic charging, interstitial hydride α and β phases are formed. On the other hand, during Pd electrodeposition, hydrogen atoms are co-deposited in the Pd films, and not only the interstitial hydrides but also vacancy-hydrogen clusters and nanovoids containing molecular hydrogen are formed in the Pd films1). In this study, we will present the findings of Pd film analysis measured using high-temperature thermal desorption spectroscopy.An alkaline plating bath containing 0.03 M (M = mol dm-3) palladium chloride (Ⅱ), 0.50 M ammonium chloride, and 0.05 M citric acid was used for electrodeposition of the Pd films. The pH of the plating bath was adjusted to 8.3 with an aqueous ammonia solution. A stainless steel (SUS304) plate was used as a substrate from which the Pd films could be peeled off. A platinum plated titanium mesh was used as a counter electrode. The bath temperature was maintained at either 298 or 278 K. The electrodeposition was performed at a constant current density of 50 A m-2. Hydrogen desorption spectra of the Pd films were measured under ultra-high vacuum by increasing the temperature from 300 K to 1300 K and then holding at 1300 K for several hours.In the thermal desorption spectrum of hydrogen from the Pd film electrodeposited at 298 K, hydrogen desorption corresponding to the desorption of the interstitial hydrogen and break-up of vacancy-hydrogen clusters was observed at temperatures below 900 K1). Above 1100 K, significant hydrogen desorption which may be assigned to the desorption of molecular hydrogen from the nanovoids with grain growth and Pd evaporation was observed. The total amount of desorbed hydrogen from the Pd film was x = 6.5 × 10-2 of which 84% was molecular hydrogen in the nanovoids desorbed at temperatures above 1100 K. In the thermal desorption spectrum of the Pd film electrodeposited at 278 K, a pronounced peak ascribed to the desorption of interstitial hydrogen appeared at around 380 K, and x = 0.15 of which 68% was molecular hydrogen in the nanovoids desorbed at temperatures above 1100 K. These results show that the existing states and concentrations of co-deposited hydrogen depend on the deposition conditions of the Pd films.This work was supported by JSPS KAKENHI Grant Number JP22K04763.1) T. Hashimoto, T. Nakamura, N. Fukumuro, S. Yae, Mater. Trans., 64, 2466 (2023). DOI: 10.2320/matertrans.MT-M2023076

Size and shape dependence of hydrogen-induced phase transformation and sorption hysteresis in palladium nanoparticles

Abstract Phase transitions of metals in hydrogen environments are critically important for applications in energy storage, catalysis, and sensing. Nanostructured metallic particles can lead to faster charging and discharging kinetics, increased lifespan, and enhanced catalytic activities. However, establishing a direct causal link between nanoparticle structure and function remains challenging. In this work, we establish a computational framework to explore the atomic configuration of a metal-hydrogen (M-H) system when in equilibrium with a H environment. This approach combines Diffusive Molecular Dynamics with an iteration strategy, aiming to minimize the system's free energy and ensure uniform chemical potential across the system that matches that of the H environment. Applying this framework, we investigate H chemical potential-composition isotherms during the hydrogenation and dehydrogenation of palladium nanoparticles, ranging in size from $3.9$ nm to $15.6$ nm and featuring various shapes including cube, rhombic dodecahedron, octahedron, and sphere. Our findings reveal an abrupt phase transformation in all examined particles during both H loading and unloading processes, accompanied by a distinct hysteresis gap between absorption and desorption chemical potentials. Notably, as particle size increases, absorption chemical potential rises while desorption chemical potential declines, consequently widening the hysteresis gap across all shapes. Regarding shape effects, we observe that, at a given size, cubic particles exhibit the lowest absorption chemical potentials during H loading, whereas octahedral particles demonstrate the highest. Moreover, octahedral particles also exhibit the highest desorption chemical potentials during H unloading. These size and shape effects are elucidated by statistics of atomic volumetric strains resulting from specific facet orientations and inhomogeneous H distributions. Prior to phase transformation in absorption, a H-rich surface shell induces lattice expansion in the H-poor core, while before phase transformation in desorption, surface stress promotes lattice compression in the H-rich core. The magnitude of the volumetric strains correlates well with the size and shape dependence, underlining their pivotal role in the observed phenomena.

Dual-phase nano-glass-hydrides overcome the strength-ductility trade-off and magnetocaloric bottlenecks of rare earth based amorphous alloys

Metal-hydrogen systems have attracted intense interest for diverse energy-related applications. However, metals usually reduce their ductility after hydrogenation. Here, we show that hydrogen can take the form of nano-sized ordered hydrides (NOH) homogeneously dispersed in a stable glassy shell, leading to remarkable enhancement in both strength and ductility. The yield strength is enhanced by 44% and the plastic strain is substantially improved from almost zero to over 70%, which is attributed to the created NOH and their interplay with the glassy shell. Moreover, the hydride-glass composite GdCoAlH possesses a giant magnetic entropy change (−ΔSM) of 18.7 J kg−1K−1 under a field change of 5 T, which is 105.5% larger than the hydrogen-free sample and is the largest value among amorphous alloys and related composites. The prominent ΔSM-ductility combination overcomes the bottlenecks of amorphous alloys as magnetic refrigerants. These results provide a promising strategy for property breakthrough of structural-functional alloys.

Phase transformation in the palladium hydrogen system: Effects of boundary conditions on phase stabilities

Different elastic constraint conditions affect the phase stabilities of metal-hydrogen systems. This is studied considering the free energy density within a chemo-mechanically coupled approach with linear elastic deformations and homogeneous concentrations. Utilizing the palladium-hydrogen alloy as a model system, the effects of various mechanical constraints in 1D, 2D and 3D are investigated. These constraints change occurring mechanical deformations and strongly influence the systems chemical potential compared to the unconstrained system. With increasing dimensionality of the constraints, large compressive mechanical stresses occur, which destabilize the hydride phase. This yields a reduced critical temperature of hydride formation. Spinodal and equilibrium miscibility gaps of the system are deduced as a function of the boundary conditions. Notably, the critical temperature of the ideal palladium-hydrogen system with 2D constraints is predicted to be ▪, revealing a driving force for hydride formation at room temperature even under these constraints.

Isotope engineering achieved by local coordination design in Ti-Pd co-doped ZrCo-based alloys

Deuterium/Tritium (D/T) handling in defined proportions are pivotal to maintain steady-state operation for fusion reactors. However, the hydrogen isotope effect in metal-hydrogen systems always disturbs precise D/T ratio control. Here, we reveal the dominance of kinetic isotope effect during desorption. To reconcile the thermodynamic stability and isotope effect, we demonstrate a quantitative indicator of Tgap and further a local coordination design strategy that comprises thermodynamic destabilization with vibration enhancement of interstitial isotopes for isotope engineering. Based on theoretical screening analysis, an optimized Ti-Pd co-doped Zr0.8Ti0.2Co0.8Pd0.2 alloy is designed and prepared. Compared to ZrCo alloy, the optimal alloy enables consistent isotope delivery together with a three-fold lower Tgap, a five-fold lower energy barrier difference, a one-third lower isotopic composition deviation during desorption and an over two-fold higher cycling capacity. This work provides insights into the interaction between alloy and hydrogen isotopes, thus opening up feasible approaches to support high-performance fusion reactors.

State-of-the-Art and Progress in Metal-Hydrogen Systems

Hydrogen is heralded as a future global energy carrier [...]

Structures of LaH10, EuH9, and UH8 superhydrides rationalized by electron counting and Jahn-Teller distortions in a covalent cluster model.

The superconducting hydrides LaH10, EuH9 and UH8 are studied using chemically intuitive bonding analysis of periodic and molecular models. We find trends in the crystallographic and electronic structures of the materials by focusing on chemically meaningful building blocks in the predicted H sublattices. Atomic charge calculations, using two complementary techniques, allow us to assign oxidation states to the metals and divide the H sublattice into neutral and anionic components. Cubic [H8]q- clusters are an important structural motif, and molecular orbital analysis of this cluster in isolation shows the crystal structures to be consistent with our oxidation state assignments. Crystal orbital Hamilton population analysis confirms the applicability of the cluster model to the periodic electronic structure. A Jahn-Teller distortion predicted by MO analysis rationalises the distortion observed in a prior study of EuH9. The impact of this distortion on superconductivity is determined, and implications for crystal structure prediction in other metal-hydrogen systems are discussed. Additionally, the performance of electronic structure analysis methods at high pressures are tested and recommendations for future studies are given. These results demonstrate the value of simple bonding models in rationalizing chemical structures under extreme conditions.

Tuning the hydrogen storage properties of Ti-V-Nb-Cr alloys by controlling the Cr/(TiVNb) ratio

This work presents an effective way to tune the thermodynamic properties of hydrogen absorption/desorption of body-centered multicomponent alloys (BCC-MCAs). A two-fold computational design was applied to screen the (TiVNb)100−xCrx system. First, the calculation of phase diagrams (CALPHAD) approach was used, aiming to BCC alloys. Secondly, a modeling was employed to predict the thermodynamics of the metal-hydrogen systems. The (TiVNb)100−xCrx alloys with x = 30, 35 and 40 were produced by arc-melting. The (TiVNb)70Cr30 and (TiVNb)65Cr35 alloys crystallize as a major BCC phase, while the (TiVNb)60Cr40 is composed mainly of a C15 Laves-type phase. The CALPHAD approach well predicted this tendency. The BCC (TiVNb)70Cr30 and (TiVNb)65Cr35 alloys absorb a large amount of hydrogen up to 2 H/M forming a dihydride. On the contrary, the (TiVNb)60Cr40 alloy displays a reduced capacity due to the low hydrogen uptake of the C15 phase. The thermodynamic of hydrogen absorption/desorption of BCC-MCAs was experimentally investigated via the acquisition of pressure-composition-temperature (PCT) diagrams. The experimental values are in good agreement with the modeling, confirming the accuracy of the computational approach. Moreover, it was demonstrated that increasing Cr content up to 35 at.% significantly impacts the thermodynamic properties, enabling reversible hydrogen absorption/desorption (for H/M ≈ 1) at room temperature.

Positron Annihilation Spectroscopy Complex for Structural Defect Analysis in Metal-Hydrogen Systems.

The current work is devoted to developing a system for the complex research of metal–hydrogen systems, including in an in situ mode. The system consists of a controlled gas reactor with a unique reaction chamber, a radioisotope positron source, and a positron annihilation spectroscopy complex. The use of the system enables in situ investigation of the defect structure of solids in hydrogen sorption–desorption processes at temperatures up to 900 °C and pressures up to 50 bar. Experimental investigations of magnesium and magnesium hydride during thermal annealing were carried out to approve the possibilities of the developed complex. It was shown that one cycle of magnesium hydrogenation–dehydrogenation resulted in the accumulation of irreversible hydrogen-induced defects. The defect structure investigation of the magnesium–hydrogen system by positron annihilation techniques was supplemented with a comprehensive study by scanning electron microscopy, X-ray diffraction analysis, and hydrogen sorption–desorption studies.

High-pressure synthesis of superconducting clathratelike YH4

Pursuing room-temperature superconductors has been a major theme in physics and material sciences since the discovery of superconductivity in 1911. In light of the tremendous progress that has been made in hydrogen-based superconductors with record ${T}_{c}\ensuremath{\sim}260\phantom{\rule{0.16em}{0ex}}\mathrm{K}$ in binary fcc $\mathrm{La}{\mathrm{H}}_{10}$, it is natural to explore more similar phases in hydrogen-rich materials. Y and La are conventionally grouped together with the lanthanide elements due to the similarities in their outer electron configurations and properties. The yttrium-hydrogen system is the most attractive candidate with high ${T}_{c}$ among all binary metal-hydrogen systems theoretically studied so far. Here we report the synthesis of the $I4/mmm\text{\ensuremath{-}}\mathrm{Y}{\mathrm{H}}_{4}$ phase and determine its superconducting transition with maximum ${T}_{c}\ensuremath{\sim}88\phantom{\rule{0.16em}{0ex}}\mathrm{K}$ at 155 GPa. The decrease in critical temperature under an external magnetic field suggests the upper critical magnetic field of about 14--22 T at megabar pressures consistent with theoretical data. By making the overlapping analysis, we elucidate that the stabilization of clathrate structures through Y atoms and the high-frequency hydrogen sublattice vibrations contribute effectively to strong electron-phonon coupling and therefore high-temperature superconductivity in the $I4/mmm\text{\ensuremath{-}}\mathrm{Y}{\mathrm{H}}_{4}$ and $Im\overline{3}m\text{\ensuremath{-}}\mathrm{Y}{\mathrm{H}}_{6}$ phases.

Characterization of LiBH4–MgH2 Reactive Hydride Composite System with Scattering and Imaging Methods Using Neutron and Synchrotron Radiation

Reversible solid‐state hydrogen storage in metal hydrides is a key technology for pollution‐free energy conversion systems. Herein, the LiBH2–MgH2 composite system with and without ScCl3 additive is investigated using synchrotron‐ and neutron‐radiation‐based probing methods that can be applied to characterize such lightweight metal–hydrogen systems from nanoscopic levels up to macroscopic scale. Combining the results of neutron‐ and photon‐based methods allows a complementary insight into reaction paths and mechanisms, complex interactions between the hydride matrix and additive, hydrogen distribution, material transport, structural changes, and phase separation in the hydride matrix. The gained knowledge is of great importance for development and optimization of such novel metal‐hydride‐based hydrogen storage systems with respect to future applications.

Hydrogen Transportation Behaviour of V-Ni Solid Solution: A First-Principles Investigation.

Hydrogen embrittlement causes deterioration of materials used in metal–hydrogen systems. Alloying is a good option for overcoming this issue. In the present work, first-principles calculations were performed to systematically study the effects of adding Ni on the stability, dissolution, trapping, and diffusion behaviour of interstitial/vacancy H atoms of pure V. The results of lattice dynamics and solution energy analyses showed that the V–Ni solid solutions are dynamically and thermodynamically stable, and adding Ni to pure V can reduce the structural stability of various VHx phases and enhance their resistance to H embrittlement. H atoms preferentially occupy the characteristic tetrahedral interstitial site (TIS) and the octahedral interstitial site (OIS), which are composed by different metal atoms, and rapidly diffuse along both the energetically favourable TIS → TIS and OIS → OIS paths. The trapping energy of monovacancy H atoms revealed that Ni addition could help minimise the H trapping ability of the vacancies and suppress the retention of H in V. Monovacancy defects block the diffusion of H atoms more than the interstitials, as determined from the calculated H-diffusion barrier energy data, whereas Ni doping contributes negligibly toward improving the H-diffusion coefficient.

Dependence of NiTi hydride stability by co-substitution by (Zr,Mg) onto Ti and (Cr,Cu) onto Ni: first-principles study

ABSTRACT The thermodynamics of hydride formation is one of the most important properties of the metal-hydrogen system, and states its potential for further uptake. For this reason, much research is focused on the use of first principle calculations as a predictive tool in the study of hydride stability. In this paper, First-principles density functional calculations were performed to predict the effect of co-substitution in NiTiH, Ti by Mg and Zr (x = 0.125, 0.25 and 0.375), as well as Ni by Cu and Cr (y = 0.125). Structural, thermodynamic stability and electronic properties were investigated. The formation enthalpy when Ti is substituted either by Mg or Zr with respect to their content is calculated and compared to the host NiTiH; it is found that the hydride stability decreases as Mg content increases while it increases when Zr content increases. The substitution of Ni by Cu destabilises the hydride while the stability of the hydride is enhanced when Ni is substituted by Cr. The simultaneous substitution of Ti by Mg (x = 0.375) and Ni by Cu (y = 0.125), leads to considerable destabilisation and an increase in cell volume of the hydride. The corresponding Ni0.875Cu0.125Ti0.625Mg0.375 compound is identified with optimum characteristics among the considered compositions, thereby can be considered as potential material for hydrogen storage.

Hydrogen as a probe for defects in materials: Isotherms and related microstructures of palladium-hydrogen thin films

Metal-hydrogen systems offer grand opportunities for studies on fundamental aspects of alloy thermodynamics. Palladium-hydrogen (Pd-H) thin films of nano crystalline, multi-oriented and epitaxial microstructures, electrolytically charged with hydrogen, serve as model systems. In these films thermodynamics of hydrogen absorption is modified by interface effects related to mechanical stress and to microstructural defects. Since in this respect hydrogen can be utilized to reveal the microstructural constituents of the films, we aim to investigate the distribution of sites (DOS) hydrogen occupies in the films’ solid solution regime. A σDOS model is proposed, taking the measured substrate-induced stress contribution to the chemical potential into account. This enables the determination of the different sites’ volume fractions and of pure site energy distributions by fitting measured isotherms. Interstitial sites, grain/domain boundary sites and deep traps are distinguished. Dislocations and vacancies are shown to have a minor impact on the films’ trapping of hydrogen atoms, while deep traps are related to the films’ surface. Enhanced binding energies in nano crystalline films can be ascribed to the tensile strain effect of grain boundaries acting on the grains. Measured surface trapping energies fit to the respective bulk values, while the trapping of hydrogen in grain/domain boundaries of the films is significantly increased. This can be interpreted with different grain/domain boundary structures. Different from octahedral interstitial site occupation, tetrahedral site occupation is suggested for grain/domain boundaries of the films.

Ultra-precision measurement of hydrogen storage capacity in metal nanoparticles using quartz crystal at low temperature and high hydrogen pressure

Hydrogen is the most abundant element in the known universe, and in a climate where the scarcity of resources is at the forefront of our minds, its value as an energy source that produces zero carbon emissions cannot be overestimated. The potential of hydrogen has caught the attention of scientists worldwide, with several candidates so far being uncovered to fulfil the role of supplying or storing hydrogen as a compressed or liquified gas. Of these candidates, metal alloys have proven to be promising options, although there is still much work to be carried out in this area in terms of operability and economic value. At Kyushu University's Department of Applied Quantum Physics, Assistant Professor Yuji Inagaki and Associate Professor Tatsuya Kawae are focused on detecting and measuring hydrogen absorption in metals. In doing so, they are also investigating fundamental properties of hydrogen-related phenomena, such as superconductivity with potential high-Tc in hydrogen-rich materials and quantum tunneling of hydrogen in metals. Their research has prompted the development of novel techniques and real-time measurement of hydrogen absorption, resulting in very real progress towards realising a world in which the metal-hydrogen system plays an essential role in reducing environmental loading.

A Heterothermic Kinetic Model of Hydrogen Absorption in Metals with Subsurface Transport

A versatile numerical model for hydrogen absorption into metals was developed. Our model addresses the kinetics of surface adsorption, subsurface transport (which plays an important role for metals with active surfaces), and bulk diffusion processes. This model can allow researchers to perform simulations for various conditions, such as different material species, dimensions, structures, and operating conditions. Furthermore, our calculation scheme reflects the relationship between the temperature changes in metals caused by the heat of adsorption and absorption and the temperature-dependent kinetic parameters for simulation precision purposes. We demonstrated the numerical fitting of the experimental data for various Pd temperatures and sizes, with a single set of kinetic parameters, to determine the unknown kinetic constants. Using the developed model and determined kinetic constants, the transitions of the rate-determining steps on the conditions of metal-hydrogen systems are systematically analyzed. Conventionally, the temperature change of metals during hydrogen adsorption and absorption has not been a favorable phenomenon because it can cause errors when numerically estimating the hydrogen absorption rates. However, by our calculation scheme, the experimental data obtained under temperature changing conditions can be positively used for parameter fitting to efficiently and accurately determine the kinetic constants of the absorption process, even from a small number of experimental runs. In addition, we defined an effectiveness factor as the ratio between the actual absorption rate and the virtually calculated non-bulk-diffusion-controlled rate, to evaluate the quantitative influence of each individual transport process on the overall absorption process. Our model and calculation scheme may be a useful tool for designing high-performance hydrogen storage systems.

A phase-field model for hydride formation in polycrystalline metals: Application to δ-hydride in zirconium alloys

We report a phase-field model for simulating metal hydride formation involving large volume expansion in single- and polycrystals. As an example, we consider δ-hydride formation in α-zirconium (Zr), which involves both displacive crystallographic structural change and hydrogen diffusion process. Thermodynamic Gibbs energy functions are extracted from the available thermodynamic database based on the sublattice model for the interstitial solid solutions. Solute-grain boundary interactions and inhomogeneous elasticity of polycrystals are taken into consideration within the context of diffuse-interface description. The stress-free transformation strains of multiple variants for hcp-Zr (α) to fcc-hydride (δ) transformation are derived based on the well-established orientation relationship between the α and δ phases as well as the corresponding temperature-dependent lattice parameters. In particular, to account for the large volume expansion, we introduced the mixed interfacial coherency concept between those phases—basal planes are coherent and prismatic planes are semi-coherent in computing the strain energy contribution to the thermodynamics. We analyzed the morphological characteristics of hydrides involving multiple structural variants and their interactions with grain boundaries. Moreover, our simulation study allows for the exploration of the possible hydride re-orientation mechanisms when precipitating under applied tensile load, taking into account the variation in the interfacial coherency between hydrides and matrix, their elastic interactions with the applied stress, as well as their morphology-dependent interactions with grain boundaries. The phase-field model presented here is generally applicable to hydride formation in any binary metal–hydrogen systems.

Structural Phase Transitions in Niobium Hydrogen Thin Films: Mechanical Stress, Phase Equilibria and Critical Temperatures.

Metal-hydrogen (M-H) systems offer grand opportunities for studies on fundamental aspects of thermodynamics and kinetics. When the system size is reduced to the nanoscale, microstructural defects as well as mechanical stress affect the systems' properties. This is contemplated for the model system of epitaxial niobium-hydrogen (Nb-H) thin films. Hydrogen absorption in metals commonly leads to lattice expansion which is hindered when the metal adheres to a flat rigid substrate. Consequently, high mechanical stress of about -10 GPa for 1 H/Nb are predicted, in theory. However, metals cannot yield such high stresses and respond with plastic deformation, commonly limiting measured stresses to -2 to -3 GPa for 100 nm Nb-H films. It will be shown that the coherency state changes with film thickness reduction, shifting the onset of plastic deformation to larger hydrogen concentrations. Below critical film thicknesses, plastic deformation is fully absent. The system then behaves purely elastic and ultra-high stress of about -10 (±2) GPa can be obtained. Arising stress controls the phase stability of M-H systems, and the coherency state strongly affects the nucleation and growth dynamics of the phase transition. In case of Nb-H thin films of less than 8 nm thickness the common phase transformation from the α-phase solid solution to the hydride phase is completely suppressed at 300 K. Related effects can be utilised to optimise metal-hydrides used in applications.

Features of Studying Atomic Hydrogen – Metal Systems

All the main areas of energy development suggest or are already implementing the use of metal-hydrogen systems. For nuclear energy, this is associated with the creation of thermostable moderators and special-purpose construction materials, for thermonuclear energy, with the behavior of the so-called first wall of fusion reactors, for hydrogen energy — storage, transportation and extraction of hydrogen. Hydrogen is the most effective moderator of fast and thermal neutrons, especially at high volumetric concentrations of hydrogen atoms in the material, i.e. at a high value of the ratio of the number of hydrogen atoms to the number of metal atoms, taking into account the heat resistance of the hydride. This paper discusses the modern methods of experimental studies of heterogeneous reactions, the topochemistry of metal – hydrogen reactions, the dependence of the interaction rate on pressure and temperature, models of surface processes occurring during the interaction of hydrogen with metal. Methods for determining the probability of adsorption of hydrogen on a metal surface, methods for measuring the activation energy of dissociation of a hydrogen molecule on a surface are also discussed. The paper describes the fea-tures of the preparation of the reactor, experimental samples and the method of their study in the study of atomic hydrogen-metal systems, the method of plasma-chemical thermogravimetry used to study heterogeneous reactions occurring in a hydrogen plasma electrodeless discharge. In order to study the mechanism of interaction of hydrogen with hydride-forming metals, a kinetic method of research is proposed. The essence of the kinetic method is that the elimination of the limiting influence of surface and diffusion processes on the rate of hydride formation using atomic hydrogen and metal foil makes it possible to directly record the formation of the corresponding phases using hydro-gen-metal kinetic curves, and also study the effect of various parameters on the rate of interaction and the formation of hydride phases.

Simulation of hydrogen thermal desorption and stability titanium hydrides TiHx

Hydrogen behavior in metals and alloys is of great importance since the hydrogen-metal systems used for absorption of nuclear radiation in thermonuclear energy production. Titanium hydride (TiH2) employed widely as a material for hydrogen storage due to its high capacity for hydrogen isotopes.The hydrogen thermal desorption of titanium hydrides with different concentrations is studied by density functional theory methods for determining the cohesion energy of H in TiHx as a function of the hydrogen concentration, and stability TiHx sample with high-level H is determined. For macro-kinetic simulation of hydrogen behavior in TiHx we use the open hydrodynamic package OpenFOAM. Using such simulations, we can model the hydrogen thermal desorption under the action of an ion beam.