Hydrogen Storage Materials Research Articles

Evaluating Diatomaceous Earth for Long-Term Use in Hydrogen Storage.

Efficient hydrogen storage is essential for its use as a sustainable energy carrier. Diatomaceous earth, a high-surface-area siliceous geomaterial, shows potential as a physisorption material for hydrogen storage. This study analyzes diatomaceous earth's long-term characteristics when subjected to high-pressure hydrogen injection. The diatomaceous earth was subjected to a hydrogen pressure of 1200 psi for a period of 80 days at room temperature. Neither notable morphological or mineralogical changes were observed. Nevertheless, there was a slight reduction in fine particles and a slight increase in larger particles. The Brunauer-Emmett-Teller (BET) surface area decreased slightly with a significant decrease in pore width. However, the hydrogen adsorption at 77 K temperature was increased significantly (45.5%) after the hydrogen storage test. Moreover, there was a delayed release of molecular water as the temperature increased. These changes suggest that a condensation reaction has occurred involving some of the opal-A silanol groups (Si-O-H), producing molecular water. Bonding through siloxane bridges (Si-O-Si) results in a significant decrease in pore width and increased hydrophobicity (i.e., the interaction between diatomaceous surface and H2 was increased), thereby enhancing hydrogen adsorption capacity. These findings indicate that diatomaceous earth holds promise as a material for hydrogen storage, with the potential for its hydrogen adsorption capacity to improve over time.

Hydrogen molecule adsorption on the MoSe2 and selected-elements (Ru, Os, Rh, Ir, N and P)-doped MoSe2 monolayers as hydrogen storage materials

Adsorption of hydrogen molecules onto the pristine MoSe2 monolayer and N-, P-, Ru-, Rh-, Os- and Ir-doped MoSe2 monolayer surfaces was investigated using periodic DFT method. Adsorption abilities of the pristine and MoSe2 doping derivatives on hydrogen molecule adsorptions are in order: Os–MoSe2 (ΔEads = −2.19 eV) > Ru–MoSe2 (ΔEads = −1.54 eV) > Ir–MoSe2 (ΔEads = −1.08 eV) > Rh–MoSe2 (ΔEads = −0.63 eV) > N–MoSe2 (ΔEads = −0.22 eV) > P–MoSe2 (ΔEads = −0.15 eV) > pristine MoSe2 (ΔEads = −0.06 eV). The adsorption energy of hydrogen onto the Os–MoSe2 surface, which is the most active derivative, stronger than the second most active, the Ru–MoSe2 by 0.65 eV (42%) was found. Nevertheless, all the MoSe2 doping derivatives utilized as hydrogen storage for energy storage purposes were suggested.

Structural-regulation of Laves phase high-entropy alloys to catalytically enhance hydrogen desorption from MgH2

Magnesium hydride (MgH2) is a promising hydrogen storage material, but slow hydrogen desorption kinetics and poor cycling stability still limit its development. Catalytic doping was demonstrated to provide effective solution for it. In this work, we develop novel Zr-based high-entropy alloys (HEAs) catalysts with different Laves phase structures to improve the hydrogen storage in MgH2. It was demonstrated that the catalyst grain size, defect density and lattice distortion have a great influence on the performance of HEAs catalysts. Specially, the C15 type Laves phase HEA exhibits a better catalytic effect than that of C14 type. The introduction of HEAs with "hydrogen pump" effect would shift the rate-limiting step of MgH2 hydrogen desorption from two-dimensional nucleation growth to two-dimension phase boundary migration, which makes it exhibit both great better hydrogen desorption kinetics enhanced by nine times and cycling stability with 92 % capacity retention after 30 cycles. This work not only highlights the impact of Laves phase crystal structure regulation on HEAs catalysts, but also provides insights into the design and development of HEAs catalysts to improve the hydrogen storage performance of MgH2.

Physical properties of the XScH3 (X: Ca, and Mg) perovskite hydrides and their hydrogen storage applications

We conducted a comprehensive investigation into the structural, mechanical, electronic, magnetic, thermodynamic, optical, and hydrogen storage properties of the novel XScH3 (X: Ca and Mg) perovskite hydrides by using density functional theory (DFT). Our calculations of the cohesive energy and elastic constants demonstrated that XScH3 compounds exhibit both thermal and mechanical stability. The metallic nature of current materials is based on the investigation of the electronic band structure and total density states. The analysis of Pugh's ratio (B/G) indicated that these hydrides were ductile materials. Furthermore, it was found that their bonding type was primarily ionic. These substances have been classified as conductors with antiferromagnetic qualities in terms of their magnetic properties. Furthermore, these materials exhibited promising effects on optical properties such as conductivity, absorption, dielectric function, and refractive index. Our predictions revealed that CaScH3 was found to be optically superior hydride. The dynamic stability of these crystals was assessed by analyzing their phonon dispersion curves and by molecular dynamics simulations. Additionally, we studied their thermal properties, including heat capacity, entropy, energy, and free energy, as functions of temperature. Furthermore, our study investigated the hydrogen storage capacity of XScH3 compounds, with CaScH3 and MgScH3, demonstrating hydrogen storage capacities of 3.43 wt% and 4.18 wt%, respectively. This study marks the first exploration of XScH3 perovskite hydrides and offers new options for hydrogen storage materials.

Innovative Design of Solid-State Hydrogen Storage and Proton Exchange Membrane Fuel Cell Coupling System with Enhanced Cold Start Control Strategy

This paper presents an innovative thermally coupled system architecture with a parallel coolant-heated metal hydride tank (MHT) designed to satisfy the hydrogen supply requirements of proton exchange membrane fuel cell s(PEMFCs). This design solves a problem by revolutionising the cold start capability of PEMFCs at low temperatures. During the design process, LaNi5 was selected as the hydrogen storage material, with thermodynamic and kinetic properties matching the PEMFC operating conditions. Afterwards, the MHT and thermal management subsystem were customised to integrate with the 70 kW PEMFC system to ensure optimal performance. Given the limitations of conventional high-pressure gaseous hydrogen storage for cold starting, this paper provides insights into the challenges faced by the PEMFC-MH system and proposes an innovative cold start methodology that combines internal self-heating and externally assisted preheating techniques, aiming to optimise cold start time, energy consumption, and hydrogen utilisation. The results show that the PEMFC-MH system utilises the heat generated during hydrogen absorption by the MHT to preheat the PEMFC stack, and the cold start time is only 101 s, which is 59.3% shorter compared to that of the conventional method. Meanwhile, the cold start energy consumption is reduced by 62.4%, achieving a significant improvement in energy efficiency. In conclusion, this paper presents a PEMFC-MH system design that achieves significant progress in terms of time saving, energy consumption, and hydrogen utilisation.

Current Research Status on The Production, Storage, And Application of Hydrogen Energy

With the development of society, the demand for energy has significantly increased, and the hydrogen energy industry is an important engine for optimizing energy structure and promoting the transformation of traditional energy. Hydrogen energy is a clean and renewable energy source with abundant sources. The unit mass of hydrogen contains a large amount of energy and can be applied in a wide range of fields. Therefore, analyzing and comparing the hydrogen energy industry chain will contribute to the healthy development of the hydrogen energy industry. This article first investigates the initial stage of development, current situation, and policies of hydrogen energy in China, Japan, and the United States, in order to gain a deeper understanding of the research status and planning of hydrogen energy in different countries. Secondly, the current mature hydrogen production methods (reforming hydrogen, electrolysis hydrogen) and hydrogen storage methods (high-pressure hydrogen storage, solid-state material hydrogen storage, organic liquid hydrogen storage materials) Hydrogen application are analyzed, and their advantages are proposed. Finally, based on research analysis, the future hydrogen energy market is introduced. This research result also provides certain reference value for enterprises that need to transform and enter the hydrogen energy field.

Evaluating hydrogen storage potential of NaNbO3-xHx: DFT-based approach

Alternative energy carrier materials are needed since non-renewable energy resources are diminishing at a fast rate. Increasingly, hydrogen storage has gained popularity as a clean energy source. For the first time, NaNbO3-xHx has been explored computationally as a potential material for hydrogen storage using the GGA-PBE approach as implemented in the CASTEP code. Structural, elastic, mechanical, electronic, and optical characteristics have been investigated to evaluate the suitability of the proposed material for hydrogen storage applications. All H-incorporated concentrations are thermodynamical and energetically stable and can be synthesized. Structural parameters vary with varying hydrogen concentrations; however, against each hydrogen concentration, the material maintains cubical geometry. The NaNbO2.7H0.3 show the highest (742.92 GPa) bulk modulus, while NaNbH3 stands with the lowest (52.48 GPa) among all. Standardizing the Poisson ratio reveals a brittle nature except for the X=0.3 composition. With increasing H-incorporation in the structure, the band gap increases (1.624 eV » 2.505 eV) and also causes electronic nature shifting (p-type → n-type); however, the band gap remains indirect over different symmetry points in BZ. Hence, have the potential for numerous optoelectronic applications. Furthermore, optical parameters, dielectric constant, refractive index, extinction coefficient, reflectivity, absorption coefficients, and loss functions are analyzed, which reveal the potential for numerous optoelectronic applications. Hydrogen storage capacity achieved up to 2.48 %, allowing this material to be utilized in energy storage systems.

A novel carbon-induced-porosity mechanism for improved cycling stability of magnesium hydride

MgH2 has been extensively studied as one of the most ideal solid hydrogen storage materials. Nevertheless, rapid capacity decay and sluggish hydrogen storage kinetics hamper its practical application. Herein, a Ni/C nano-catalyst doped MgH2 (MgH2Ni/C) shows an improved hydrogen absorption kinetics with largely reduced activation energy. Particularly, the MgH2Ni/C displays remarkable cycling stability, which maintains a high capacity of 6.01 wt% (98.8 % of initial capacity) even after 50 full hydrogen ab/desorption cycles, while the undoped MgH2 counterpart retains only 85.2 % of its initial capacity. Detailed microstructure characterizations clearly reveal that particle sintering/growth accounts primarily for the deterioration of cycling performance of undoped MgH2. By comparison, MgH2Ni/C can maintain a stable particle size with a growing porous structure during long-term cycling, which effectively increases the specific surface of the particles. A novel carbon-induced-porosity stabilization mechanism is proposed, which can stabilize the proportion of rapid hydrogen absorption process, thus dominating the excellent cycling performance of MgH2Ni/C. This study provides new insights into the cycling stability mechanism of carbon-containing Mg-based hydrogen storage materials, thus promoting their practical applications.

Preliminary experimental studies into the storage capacity of cryogenic hydrogen in aerogel blanket materials

The abundance and diversity of hydrogen applications necessitates continued and accelerated research into advanced storage technologies. Traditionally, hydrogen has been stored as either a high-pressure, warm gas; or a low-pressure, cryogenic liquid. Methods such as cryo-supercritical and cryo-adsorbed have been explored, but are not yet mainstream. Cryo-adsorbed is attractive because higher storage densities at higher temperatures than liquid may be achieved. Recently NASA, in partnership with Eta Space, Southwest Research Institute, the University of Central Florida, and Air Liquide, have been exploring the use of inexpensive, commercially available silica aerogel blanket materials for cryo-adsorbed hydrogen storage. Unlike most adsorbents, aerogel blanket is not a powder, but a robust, composite material that can be formed into complex shapes to aid in more efficient storage system designs, and has already been proven to uptake large quantities of fluids such as nitrogen and oxygen. Recent experimental efforts into the uptake of low-pressure hydrogen gas at 77 K, and liquid hydrogen at normal boiling point (NBP) will be discussed. Although preliminary in nature, the test results are promising, showing up to a 49% increase in storage density at 77 K over the gas alone, and greater than a one-to-one volume equivalency with NBP LH2.

Improved dehydrogenation performance of LiAlH4 doped with BaMnO3

Due to its high gravimetric capacity of hydrogen (10.5 wt%), LiAlH4 has been regarded as a promising material for solid-state hydrogen storage material for onboard usage. However, high decomposition temperature, poor kinetics and irreversibility retard its application. To counter this problem, various weight percentages of BaMnO3 are introduced into the LiAlH4 system as an additive in this work. As a result, the starting hydrogen release of LiAlH4 was reduced to 109−115 °C and the second desorption temperature occurred at around 134−158 °C, much lower than pure LiAlH4. The isothermal desorption kinetics also proved that faster desorption kinetics can be observed at 90 °C for 80 min. About 2.00−2.60 wt% of H2 could be desorbed by the composite, whereas only <1.00 wt% of H2 was desorbed by undoped LiAlH4. Additionally, adding BaMnO3 reduced the activation energies by 30 kJ/mol for the first stages and 34 kJ/mol for the second stages. Based on the X-ray diffraction result, the active species formed of MnO2 and Ba or Ba−containing materials are believed to be responsible for the noticeable enhancement in the desorption properties of LiAlH4.

HYDROGEN SORPTION IMPROVEMENT OF NaAlH4 CATALYSED BY K2 SiF6 FOR SOLID STATE HYDROGEN STORAGE

Sodium alanate (NaAlH4) has been recognised as a complex metal hydride that is frequently used as a hydrogen storage material. However, dealing with its poor kinetic characteristics and high decomposition temperatures becomes challenging. This research added potassium hexafluorosilicate (K2SiF6) as a catalyst to reduce the dehydrogenation temperature and improve sorption kinetics compared to the undoped NaAlH4. The dehydrogenation temperature of the NaAlH4 composite with 10 wt.% K2SiF6 addition was determined to be 145°C, a decrease of about 31% compared to 210°C for the undoped NaAlH4. The 10 wt.% K2SiF6-added NaAlH4 samples released roughly 1.77 wt.% hydrogen at 200°C after 60 minutes of dehydrogenation, representing faster dehydrogenation kinetics, but the milled NaAlH4 only produced around 1.39 wt.% of hydrogen. According to Kissinger’s analysis, the apparent activation energy, Ea for the decomposition of NaAlH4 was 87.74 kJ/mol in 1st stage and for NaAlH4 10 wt.% K2SiF6 composite, lowered by 30.45 kJ/mol or 25.8% than as-milled NaAlH4 (118.19 kJ/mol). The enhancement of the dehydrogenation performance of the NaAlH4-K2SiF6 composite can be attributed to the formation of the new phases of KAlF4. These findings might alter the reaction pathway of the composite system and improve its thermodynamic properties. The improvement of dehydrogenation performance and the discovery of the role played by KAlF4 in the dehydrogenation process of the NaAlH4-K2SiF6 composite give us valuable insights for developing and optimising future hydrogen storage materials.

Magnesium Magic: State-of-the-Art Nanocrystalline Materials Paving the Way for Hydrogen Storage.

Hydrogen has been regarded as a promising alternative to traditional fossil fuels, presenting itself as a viable and environmentally friendly energy choice. The design and fabrication of highly efficient hydrogen storage materials is crucial to the wide utilization of hydrogen-based technologies. Magnesium-based nanocrystalline materials have received significant interest in the field of hydrogen storage due to their remarkable hydrogen storage capabilities and release efficiency. This review emphasizes on the most useful techniques including vapor deposition, sol-gel synthesis, electrochemical deposition, magnetron sputtering, and template-assisted approaches used for the fabrication of Magnesium-based nanocrystalline hydrogen storage materials (Mg-NHSMs), stressing their advantages, limitations, and recent advancements. These cutting-edge techniques demonstrate their significance in offering useful insights into the performance of Mg-NHSMs. Further, this review describes various applications of Mg-NHSMs. In addition, this review highlights the conclusion and future perspectives on the improvement of magnesium based nanocrystalline materials for efficient hydrogen storage.

Materials for green hydrogen production, storage, and conversion

Materials for green hydrogen production, storage, and conversion

Ultrafine nickel-rhodium nanoparticles anchored on two-dimensional vanadium carbide for high performance hydrous hydrazine decomposition at mild conditions

The development of heterogeneous supported nanocatalysts with a high kinetics combined with low cost is off importance but remains still challenged for hydrazine hydrate served as a promising hydrogen storage material. Herein, by virtue of surficial functional groups, ultrafine NiRh NPs were monodispersed on the two-dimensional V2C surface via a conventional wet chemical co-reduction. The optimized NiRh/V2C system demonstrates an excellent catalytic performance toward selectively catalyzing dehydrogenation of hydrazine hydrate, affording 100% H2 selectivity with the turnover frequency (TOF) value of 987.5 h−1 at 323 K. Such an enhancement is mainly attributed to synergistic effect of nanosystem, which will optimize local surface energy and promote electron transfer in NiRh/V2C system, thereby improving the kinetic selectivity of catalytic hydrazine hydrate decomposition. This work has provided a facile strategy for developing nanocatalysts with high kinetics that could enable huge industrial applications in the future.

Zero-emission hydrogen production by CH4 pyrolysis over Ni/Ferrierite catalyst: Examination of the deactivated catalysts for electrical conductivity and H2 storage properties

An economic route for the generation of hydrogen and utilization of carbon nanofibers (CNFs) was achieved by CH4 cracking over 20 wt%Ni/FER catalyst. The deactivated catalyst demonstrated electrical conductivity and hydrogen storage properties. TEM images displayed open mouths of CNFs and XRF data showed nearly 70% of nickel was recovered from the deactivated catalyst. Impedance studies of the CNFs exhibit prominence as battery electrodes due to their significant conductivity in the presence of nickel. While the hydrogen storage capacity was around 0.151 mmol (gcat)−1 of H2 on the obtained CNFs, it was increased to 0.361 mmol (gcat)−1 upon Ni recovery from the CNFs. A seven-fold increase in the H2 storage of ∼0.862 mmol (gcat)−1 was obtained upon Li doping, exhibiting its distinct property as a hydrogen storage material. The fresh, reduced, used, and deactivated catalysts were characterized by BET-SA, H2-TPR, XRD, Raman spectroscopy, TEM, and H2 pulse chemisorption and Ni/FER was established as an economically viable catalyst for high rates of H2 and CNF production.

Hydrogen release of NaBH4 below 60 °C with binary eutectic mixture of xylitol and erythritol additive

NaBH4 was widely regarded as a low-cost hydrogen storage material due to its high-weight hydrogen capacity of approximately 10.8% (mass) and high volumetric hydrogen capacity of around 115 g·L–1. However, it exhibits strong stability and requires temperatures above 500 °C for hydrogen release in practical applications. In this study, two polyhydric alcohols xylitol and erythritol (XE) were prepared as a binary eutectic sugar alcohol through a grinding-melting method. This binary eutectic sugar alcohol was used as a proton-hydrogen carrier to destabilize NaBH4. The 19NaBH4-16XE composite material prepared by ball milling could start releasing hydrogen at 57.5 °C, and the total hydrogen release can reach over 88.8% (4.45% (mass)) of the theoretical capacity. When the 19NaBH4-16XE composite was pressed into solid blocks, the volumetric hydrogen capacity of the block-shaped composite could reach 67.2 g·L–1. By controlling the temperature, the hydrogen desorption capacity of the NaBH4-XE composite material was controllable, which has great potential for achieving solid-state hydrogen production from NaBH4.

Experimental Investigation of Phase Equilibria in the Ti-Cr-V System at 1000–1200 °C

Ti-Cr-V-based alloys have been utilized across various domains, including aerospace structural and functional materials and hydrogen storage materials. Investigating the phase relations in the Ti-Cr-V system is significant in supporting the material design for these applications. In the present work, the isothermal sections at 1000, 1100, and 1200 °C for the Ti-Cr-V system were precisely determined through a systematic investigation using scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), and X-ray diffraction (XRD). The phase region of Cr2Ti was entirely elucidated for the first time. As the temperature decreased from 1200 to 1000 °C, the V solubility range of Cr2Ti increased from 5.3 wt.% to 10.0 wt.%, while the Ti solubility range essentially remained constant at approximately 31.0–33.9 wt.%. In addition, it was suggested that the stable structure of Cr2Ti was C36 at 1200 °C and C15 at 1000 and 1100 °C. The present work will support thermodynamic re-assessment research.

Sc-Modified C3N4 Nanotubes for High-Capacity Hydrogen Storage: A Theoretical Prediction.

Utilizing hydrogen as a viable substitute for fossil fuels requires the exploration of hydrogen storage materials with high capacity, high quality, and effective reversibility at room temperature. In this study, the stability and capacity for hydrogen storage in the Sc-modified C3N4 nanotube are thoroughly examined through the application of density functional theory (DFT). Our finding indicates that a strong coupling between the Sc-3d orbitals and N-2p orbitals stabilizes the Sc-modified C3N4 nanotube at a high temperature (500 K), and the high migration barrier (5.10 eV) between adjacent Sc atoms prevents the creation of metal clusters. Particularly, it has been found that each Sc-modified C3N4 nanotube is capable of adsorbing up to nine H2 molecules, and the gravimetric hydrogen storage density is calculated to be 7.29 wt%. It reveals an average adsorption energy of -0.20 eV, with an estimated average desorption temperature of 258 K. This shows that a Sc-modified C3N4 nanotube can store hydrogen at low temperatures and harness it at room temperature, which will reduce energy consumption and protect the system from high desorption temperatures. Moreover, charge donation and reverse transfer from the Sc-3d orbital to the H-1s orbital suggest the presence of the Kubas effect between the Sc-modified C3N4 nanotube and H2 molecules. We draw the conclusion that a Sc-modified C3N4 nanotube exhibits exceptional potential as a stable and efficient hydrogen storage substrate.

Amorphous mixed transition metal oxides: A novel catalyst for boosting dehydrogenation of MgH2

Magnesium hydride (MgH2) has been recognized as a promising hydrogen storage material. However, the sluggish hydrogen desorption kinetics is one of the main factors hindering its practical applications. To enhance the dehydrogenation kinetics of MgH2, an amorphous mixed TiO2-ZrO2-V2O5 catalyst is synthesized in this work. After adding the as-synthesized catalyst into MgH2 by ball milling, the dehydrogenation activation energy can be decreased to 65.7 kJ mol−1. Meanwhile, the catalyzed MgH2 shows excellent cycling stability after fifty hydrogen absorption-desorption cycles. The significant improvement of hydrogen desorption kinetics is attributed to the synergistic effect of abundant oxygen vacancies and in situ formed multivalent species in the catalyst. This highlights the importance of designing and synthesizing efficient catalysts for dehydrogenation of MgH2.

Heteroatom sulfur exploration for enhancing MgH2 dehydrogenation: A theoretical and experimental analysis

High operating temperatures and sluggish kinetics constrain the commercial application of magnesium-based hydrogen storage materials. To overcome these drawbacks, this work investigates heteroatom sulfur as a catalyst to improve the dehydrogenation of MgH2 using density functional theory (DFT) and experimental validation. Heteroatom sulfur can influence the dehydrogenation of MgH2 by modulating interfacial carbon-magnesium interactions and substituting surface hydrogen sites. In particular, DFT calculations reveal that sulfur functional groups facilitate charge transfer and significantly reduce the energy barrier of MgH2 by 0.32 eV–1.59 eV. Substitution of sulfur atoms at surface hydrogen sites of MgH2 notably improves dehydrogenation by weakening the Mg–H bond and enabling a sulfur-assisted two-step dehydrogenation mechanism. Experimental results further confirm these theoretical findings. The MgH2/900C–20SO2 sample exhibits that the peak dehydrogenation temperature and the onset dehydrogenation temperature were 19.8 °C and 64 °C lower than that of pure MgH2, and a significant reduction in activation energy from 134.52 kJ mol−1 to 92.12 kJ mol−1. This research provides a comprehensive understanding of the catalytic effects of heteroatom sulfur on MgH2 and offers crucial theoretical and practical insights for the development of more efficient magnesium-based hydrogen storage systems.