Development Of Hydrogen Storage Materials Research Articles

An overview of TiFe alloys for hydrogen storage: Structure, processes, properties, and applications

Hydrogen-based energy systems offer potential solutions for replacing fossil fuels in the future. However, the practical utilization of hydrogen energy depends partly on safe and efficient hydrogen storage techniques. The development of hydrogen storage materials has attracted extensive interest for decades. Solid-state hydrogen storage systems based on metal hydride materials provide great promises for many applications. Recently, interest has been revived in TiFe alloys as a prime candidate for stationary hydrogen storage material. The advantages of TiFe alloys over some of the other solid metal hydrides include that it can hydrogenate and dehydrogenate at near room temperature under near atmospheric pressures and that it is a low-cost material because there are abundant supplies of Fe and Ti on the earth's crust. However, the TiFe alloy must be activated at relatively high temperatures (400–450 °C) and high pressure of hydrogen (65 bar) before it can be hydrogenated, which is a hindrance to the industrial-scale application of TiFe alloys. The materials science community on hydrogen storage materials has conducted and reported considerable amounts of studies on TiFe-based alloys. In this work, we provided a comprehensive review of TiFe-based alloys. The fundamentals and synthesis approaches of TiFe-based alloys were summarized. The activation properties of TiFe-based alloys including the understanding of the activation mechanisms and the methods for improving the activation kinetics were reviewed. Moreover, the cycle stability and anti-poisoning ability were discussed. Finally, the potential applications and the perspective of TiFe-based alloys were introduced.

DFT study of efficient hydrogen storage on B12@Ca14 cage

Hydrogen, as a zero-carbon energy carrier, has attracted considerable attention of scientific community. Therefore, the development of hydrogen storage materials has always been a hot topic. Currently, there have been numerous researches on hydrogen storage performance of boron nanostructures decorated by alkaline-Earth atoms. Here based on first-principles calculations, a core–shell B12@Ca14 structure with D 2h symmetry has been proposed. Surprisingly, 14 Ca atoms in the metal shell of the B12@Ca14 structure can form a good package for B12 core without aggregation, thus forming a novel hydrogen storage material with all-metal atomic shell, which also provides a new idea for the research of hydrogen storage materials. Molecular dynamics simulation and vibration frequency analysis have been revealed the thermodynamic and kinetic stability of the B12@Ca14 structure. The analysis of binary system illustrates that the structure can be used as a building block for nano-assembly. For the hydrogen storage performance of the structure, the research results show that the B12@Ca14 structure can adsorb about 75 H2 molecules, with a high hydrogen storage mass density of 18.0 wt%. What’s more, non-covalent interaction analysis verifies that H2 molecules are adsorbed by weak interactions.

The feasibility of a spillover mechanism in the field of hydrogen storage material

Hydrogen storage is required to make a breakthrough to commercializing hydrogen energy; however, the development of hydrogen storage material based on both physisorption and chemisorption faced their limit. To this end, researchers pay attention to applying the spillover mechanism to hydrogen storage, and a lot of research report the positive effect of the introduction of Pt to dissociate hydrogen molecule into porous material on hydrogen storage performance. Moreover, the mechanism of migration and adsorption of dissociated hydrogen from Pt is suggested, which is so-called spillover mechanism. However, some researchers raise doubt about the feasibility of the spillover mechanism in hydrogen storage. In this paper, we verify the effect of the introduction of Pt on hydrogen storage performance and discuss its feasibility.

Toward a Hydrogen Economy: Development of Heterogeneous Catalysts for Chemical Hydrogen Storage and Release Reactions

Chemical hydrogen storage and release processes are essential steps for the implementation of new energy vectors. In general, the individual reactions involved in such technologies need catalysts to allow discharging and recharging hydrogen in a stable and efficient manner. In recent years, the development of hydrogen storage materials and their use in renewable energy systems have experienced rapid growth. While many academic works in this area make use of homogeneous catalysts, there is the practical need for heterogeneous catalytic systems, which often can be more easily applied on a larger industrial scale. In this Review we highlight the present status of using heterogeneous materials as catalysts for both chemical hydrogen storage and release systems, providing detailed reaction parameters for practical demonstration. The pros and cons of the currently known systems and their differences relative to homogeneous catalysts are also explained and critically discussed.

Pd3P nanoparticles decorated P-doped graphene for high hydrogen storage capacity and stable hydrogen adsorption-desorption performance

The emergence of graphene provides a new research vector for the development of hydrogen storage materials. Herein, we firstly report a Pd3P nanoparticles decorated P-doped graphene material by a facile pyrolysis method for hydrogen storage. The size of Pd3P particles is distributed on the graphene surface uniformly in the range of 20–30 nm. It has a high gravimetric density of hydrogen storage of 3.66 wt% at mild conditions (298 K, 4 MPa). When the temperature drops to 253 K, the hydrogen storage capacity increases to 3.94 wt%; whereas at the pressure of 5.5 MPa and 298 K, the hydrogen storage capacity is up to 4.7 wt%. The Pd3P nanoparticles decorated P-doped graphene has both physical and chemical hydrogen adsorption mechanisms during the hydrogen storage process. The hydride produced by chemical adsorption remains stable even at 498 K, which is the main reason for 1.03 wt% of the capacity loss during the hydrogen adsorption-desorption cycle. After 4 cycles of hydrogen adsorption-desorption at 298 K and 4 MPa, the effective hydrogen storage capacity of Pd3P nanoparticles decorated P-doped graphene is 2.63 wt%, and the Pd3P nanoparticles on the graphene are evenly distributed with stable structure after cycles, which is conducive to the realization of reversible hydrogen storage.

Recent Progress Using Solid-State Materials for Hydrogen Storage: A Short Review

With the rapid growth in demand for effective and renewable energy, the hydrogen era has begun. To meet commercial requirements, efficient hydrogen storage techniques are required. So far, four techniques have been suggested for hydrogen storage: compressed storage, hydrogen liquefaction, chemical absorption, and physical adsorption. Currently, high-pressure compressed tanks are used in the industry; however, certain limitations such as high costs, safety concerns, undesirable amounts of occupied space, and low storage capacities are still challenges. Physical hydrogen adsorption is one of the most promising techniques; it uses porous adsorbents, which have material benefits such as low costs, high storage densities, and fast charging–discharging kinetics. During adsorption on material surfaces, hydrogen molecules weakly adsorb at the surface of adsorbents via long-range dispersion forces. The largest challenge in the hydrogen era is the development of progressive materials for efficient hydrogen storage. In designing efficient adsorbents, understanding interfacial interactions between hydrogen molecules and porous material surfaces is important. In this review, we briefly summarize a hydrogen storage technique based on US DOE classifications and examine hydrogen storage targets for feasible commercialization. We also address recent trends in the development of hydrogen storage materials. Lastly, we propose spillover mechanisms for efficient hydrogen storage using solid-state adsorbents.

Porous metal-organic frameworks for hydrogen storage.

The high gravimetric energy density and environmental benefits place hydrogen as a promising alternative to the widely used fossil fuels, which is however impeded by the lack of safe, energy-saving and cost-effective H2 storage systems. The use of solid adsorbents as candidate materials offers a less energy-intensive way of storing hydrogen. The exceptional diversity and tunability of the chemical composition, topological structure, and surface chemistry together with large surface area position porous metal-organic frameworks as promising hydrogen storage material candidates. In this review, we first introduce several classes of important metal-organic frameworks for hydrogen storage, and then highlight the progress associated with the key challenges to be addressed, including the improvement of hydrogen-framework interaction required for enhancing room-temperature hydrogen storage capacities, and the optimization/balance of both gravimetric and volumetric storage/working capacities. In particular, the strategies used to tune and enhance hydrogen binding energies have been comprehensively reviewed. Future development prospects and related challenges of using porous metal-organic frameworks as hydrogen storage materials are also outlined. This feature review provides a wide perspective and insightful thoughts and suggestions for hydrogen storage using metal-organic frameworks, and promotes the further development of hydrogen storage materials to realize a hydrogen economy.

Development of Ca–Mg–H2–ZrCl4 composite for hydrogen storage applications

Both CaH2 and MgH2 are good candidate for the development of hydrogen storage materials because of their high hydrogen storage capacity. However, both the hydrides are quite stable thermodynamically and required high temperature for hydrogen sorption process. The MgH2–CaH2 composite could show the favourable hydrogen sorption reaction because of Ca–Mg intermetallic formation. The idea motivated to perform the experiments starting with these metal hydrides. It has been found that the hydrogen sorption reaction kinetics improved substantially. The dihydrogen product has shown a few intermetallic of magnesium and calcium. The hydrogen sorption temperature and pressure of the alloy was remarkably improved by the doping with ZrCl4 as a catalyst. The activation energy and the thermodynamic parameters of un-catalyzed and catalyzed alloy were studied. Present studied indicated that the CaH2–MgH2–ZrCl4 could be a potential candidate for the mobile hydrogen storage system.

De-hybridization effect of transition metal catalysts on AlH4-based hydrogen storage materials

Understanding the microscopic impact of catalysis on the de-hydrogenation process of hydrides is crucial for the development of hydrogen storage materials. In this paper, density functional theory calculations are employed to study the adsorption and dissociation of the AlH4 cluster, which is the building block of many complex hydrides, on a series of transition metal surfaces. We find that the hybrid bonding of the AlH4 cluster is weakened when adsorption on metal surfaces and the Al–H bonds are stretched accordingly. This de-hybridization effect enhances from Sc to Ni in correlation with the work function. Based on the results, we predict Ni to be the most effective transition metal in lowering the de-hydrogenation barrier of AlH4-based hydrides. Detail electronic structure analysis show that the de-hybridization effect mainly resulted from the charge transfer between metals surface and AlH4 clusters. Our results provide deep insight into improving the properties of hydrogen storage materials.

Hydrous Hydrazine Decomposition for Hydrogen Production Using of Ir/CeO2: Effect of Reaction Parameters on the Activity.

In the present work, an Ir/CeO2 catalyst was prepared by the deposition–precipitation method and tested in the decomposition of hydrazine hydrate to hydrogen, which is very important in the development of hydrogen storage materials for fuel cells. The catalyst was characterised using different techniques, i.e., X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), scanning electron microscopy (SEM) equipped with X-ray detector (EDX) and inductively coupled plasma—mass spectroscopy (ICP-MS). The effect of reaction conditions on the activity and selectivity of the material was evaluated in this study, modifying parameters such as temperature, the mass of the catalyst, stirring speed and concentration of base in order to find the optimal conditions of reaction, which allow performing the test in a kinetically limited regime.

Theoretical Framework for Encapsulation of Inorganic B12N12 Nanoclusters with Alkaline Earth Metals for Efficient Hydrogen Adsorption: A Step Forward toward Hydrogen Storage Materials

The increasing demand for energy storage materials has gained considerable attention of scientific community toward the development of hydrogen storage materials. Hydrogen has become more important, as it not only works efficiently in different processes but is also used as an alternative energy resource whenever it is combined with a cell technology like fuel cell. Herein, efforts are being made to develop efficient hydrogen storage materials based on alkaline earth metal (beryllium, magnesium, and calcium)-encapsulated B12N12 nanocages. Quantum chemical calculations were performed using density functional theory (DFT) and time-dependent DFT at B3LYP/6-31G(d,p) and CAM-B3LYP/6-311+G(d,p) levels of theory for all the studied systems. The adsorption energies of Be-B12N12, Mg-B12N12, and Ca-B12N12 systems suggested that Mg and Ca are not fitted accurately in the cavity of nanocages because of their large size. However, H2 adsorbed efficiently on the metal-encapsulated systems with high adsorption energy values. Furthermore, dipole moment and QNBO (Charges-Natural Bond Orbital) calculations suggested that a greater charge separation is seen in H2-adsorbed metal-encapsulated systems. The molecular electrostatic potential analysis also unveiled the different charge sites in the studied systems and also demonstrated the charge separation upon hydrogen adsorption on metal-encapsulated systems. Partial density of states analysis was performed in the support of frontier molecular orbital distribution that indicates the narrow highest occupied molecular orbital-lowest unoccupied molecular orbital energy gap in hydrogen-adsorbed metal-encapsulated systems. Results of all analyses and global descriptions of reactivity suggested that the designed H2-adsorbed metal-encapsulated B12N12 systems are efficient systems for designing future hydrogen storage materials. Thus, these novel kinds of systems for efficient hydrogen storage purposes have been recommended.

Adsorption equilibrium and charge/discharge characteristics of hydrogen on MOFs

For obtaining relevant information about the development of hydrogen storage materials from metal organic frameworks (MOFs), MIL-101(Cr) was selected and synthesized for analyzing the adsorption equilibrium and characteristics of charge and discharge. The specific surface area, pore size distribution (PSD) of the sample were determined by 77.15 K nitrogen adsorption data. Isotherms of hydrogen adsorption on the sample were volumetrically measured at 77.15 K and 87.15 K, 0–100 KPa and 0–6 MPa. Henry law constants and Toth equation were respectively used to determine the isosteric heat of adsorption. A 3.2 L conformable vessel, which can meet the fuel consumption of 7.5 kW PEMFC under typical working condition for about 10 min, was designed and undergone charge and discharge tests at ambient temperature and 77.15 K under the flow rate 10–50 L·min−1. Results show that the limit isosteric heat of adsorption on the sample is 7.368 kJ·mol−1, while the mean Isosteric heat determined by the Toth potential function is 2.925 kJ·mol−1. Results also reveal that, at 77.15 K, the ratio of hydrogen released is 80%, 79.4%, 77.2% and 76.1% at the flow rate of 20–50 L·min−1; while at 301.15 K, the ratio is 85.1%, 85.0% and 82.3% with corresponding flow rate 10–30 L·min−1. It suggests that the storage amount and the characteristics of charge/discharge on hydrogen-MIL-101(Cr) system at cryogenic temperature can meet the fuel requirements of the fuel cell.

Recent Developments of Effective Catalysts for Hydrogen Storage Technology Using N-Ethylcarbazole

Hydrogen energy is considered to be a desired energy storage carrier because of its high-energy density, extensive sources, and is environmentally friendly. The development of hydrogen storage material, especially liquid organic hydrogen carrier (LOHC), has drawn intensive attention to address the problem of hydrogen utilization. Hydrogen carrier is a material that can reversibly absorb and release hydrogen using catalysts at elevated temperature, in which LOHC mainly relies on the covalent bonding of hydrogen during storage to facilitate long-distance transportation and treatment. In this review, the chemical properties and state-of-the-art of LOHCs were investigated and discussed. It reviews the latest research progress with regard to liquid organic hydrogen storage materials, namely N-ethylcarbazole, and the recent progress in the preparation of efficient catalysts for N-ethylcarbazole dehydrogenation by using metal multiphase catalysts supported by carbon–nitrogen materials is expounded. Several approaches have been considered to obtain efficient catalysts such as increasing the surface area of the support, optimizing particle size, and enhancing the porous structure of the support. This review provides a new direction for the research of hydrogen storage materials and considerations for follow-up research.

Predicting the hydrogen release ability of [formula omitted]-based mixtures by ensemble machine learning

The prediction of hydrogen release ability is indispensable to evaluating hydrogen storage performance of LiBH4-based mixtures before experimentation. To achieve this goal, ensemble machine learning is employed to automatically infer the relationship between factors (i.e., sample preparation, mixing conditions and operational variables) and target (H2 release amount), providing exceptional insight into hydrogen release ability. Specifically, the importance ranking of major variables for the hydrogen release of LiBH4 has been proposed for the first time based on the constructed uni-component catalysts database. We train our developed EoE model on 2,071 uni-component catalysts data and attempt to predict the hydrogen release amounts of LiBH4 doping with the unseen bi-component catalysts. The appealing results demonstrate the effectiveness and robustness of EoE. The procedure established in this study presents a novel approach for accelerating the research and development of hydrogen storage materials over various catalysts.

Low-cost CuNi-CeO2/rGO as an efficient catalyst for hydrolysis of ammonia borane and tandem reduction of 4-nitrophenol

Low-cost metallic nanoparticles as catalysts with good performance are highly desired for the development of hydrogen storage materials. In this work, ceria-doped CuNi nanoparticles were successfully immobilized on the surfaces of reduced graphene oxide (rGO) by a simple co-reduction approach in aqueous solution at room temperature, characterized by ICP-OES, XRD, TEM, SEM-EDS and XPS techniques. The as-synthesized CuNi-CeO2/rGO nanocomposites with various metal contents had been employed as heterogeneous catalysts for the hydrolytic dehydrogenation of ammonia borane (NH3BH3, AB) under mild conditions. The optimal catalyst of Cu0.8Ni0.2-CeO2/rGO with CeO2 content of 13.9 mol% exhibited an excellent catalytic activity with the exceedingly high TOF value of 34.4·molH2·molcatalyst−1·min−1 at 298 K. The apparent activation energy was calculated to be 19.1 kJ mol−1, even lower than most of noble-metal-based catalysts for AB dehydrogenation. The detailed kinetics of AB hydrolysis catalyzed by Cu0.8Ni0.2-CeO2/rGO had been investigated on different concentrations of catalyst, substrate and temperatures. Moreover, the obtained in situ hydrogen from AB hydrolysis can be further applied to reduce 4-nitrophenol with a high TOF value of 8.1 min−1 at room temperature. The high catalytic activity of Cu0.8Ni0.2-CeO2/rGO would be contributed to the small size of CuNi-CeO2 NPs, metal-metal synergy, and the metal-support interaction.

Iron Catalyzed Dehydrocoupling of Amine- and Phosphine-Boranes.

Catalytic dehydrocoupling methodologies, whereby dihydrogen is released from a substrate (or intermolecularly from two substrates) is a mild and efficient method to construct main group element‐main group element bonds, the products of which can be used in advanced materials, and also for the development of hydrogen storage materials. With growing interest in the potential of compounds such as ammonia‐borane to act as hydrogen storage materials which contain a high weight% of H2, along with the current heightened interest in base metal catalyzed processes, this review covers recent developments in amine and phosphine dehydrocoupling catalyzed by iron complexes. The complexes employed, products formed and mechanistic proposals will be discussed.

(Invited) An Overview of the Hydrogen Materials - Advanced Research Consortium (HyMARC), a DOE Energy Materials Network Consortium, to Accelerate Development of Hydrogen Storage Materials

The DOE launched the Hydrogen Materials – Advance Research Consortium (HyMARC) to address the key barriers impeding the development of hydrogen storage materials that meet the demands of transportation applications. The consortium is composed of a national laboratory core team, and individual materials development projects selected from academia, industry and other Federally Funded Research and Development Centers. The goal of the DOE Hydrogen Storage Program is to enable the widespread commercialization of hydrogen and fuel cell technologies through the development of advanced hydrogen storage technologies that meet the onboard storage demands. Commercial fuel cell electric vehicles are being released today that use high-pressure 700 bar hydrogen storage onboard, and the hydrogen fuel infrastructure is being installed to support fast fueling of 700 bar onboard hydrogen storage. The high-pressure tanks are significantly more expensive, larger and heavier than conventional gasoline or diesel fuel tanks. Additionally high pressure delivery to the vehicle adds significantly to the cost of fuel and creates reliability issues at the station. Materials-based storage offers an opportunity to enable storage at high density in a compact container at lower pressures, providing the potential to decrease the cost of the onboard hydrogen storage system and the fueling infrastructure. The HyMARC national laboratory core team, composed of Sandia (SNL) - lead, Lawrence Livermore (LLNL), and Lawrence Berkeley National Laboratories (LBNL), is tasked with carrying out foundational research to understand the interaction of hydrogen with materials in relation to the formation and release of hydrogen from hydrogen storage materials. This effort includes the development of computational material design tools, synthetic and characterization methodologies, and online databases of hydrogen storage materials properties and computational data that will accelerate materials discovery and development for on-board hydrogen storage applications. Individual materials development projects are selected to work with the national laboratory core team to apply the tools and accelerate the development of materials tailored to meet the needs for transportation hydrogen storage applications.

Recent progress in hydrogen-rich materials from the perspective of bonding flexibility of hydrogen

The bonding flexibility of hydrogen is a source of various interesting functionalities in hydrides. Here, we illustrate the benefits of this flexibility through several selected examples of recent progress in the development of hydrogen storage materials. From the viewpoint of electronegativity, we discuss the diverse cohesion and materials science underlying the bonding flexibility of hydrogen in hydrides.

Thermodynamic modelling of Mg(BH4)2

Application of the Calphad method to the description of thermodynamic properties in complex borohydride-based systems may allow a faster development of hydrogen storage materials. It is, however, limited by the low number of available thermodynamic description for borohydrides in thermodynamic databases. In the present work, a Calphad assessment of Mg(BH4)2 has been performed, considering available thermodynamic data. DFT calculations have been performed in order to provide missing thermodynamic data and to calculate the relative stability of the α, β and γ polymorphs. Experimental results have been compared detecting inconsistencies between them.The database obtained has been used to estimate driving forces for several dehydrogenation reactions. The dehydrogenation reaction leading to the formation of MgB2 and gaseous hydrogen is the most favoured thermodynamically, even if at low temperatures the formation of MgB12H12 is competitive. On the contrary, positive driving forces have been calculated for the decomposition into B2H6 and Mg(B3H8)2.

Accelerating the Understanding and Development of Hydrogen Storage Materials: A Review of the Five-Year Efforts of the Three DOE Hydrogen Storage Materials Centers of Excellence

A technical review of the progress achieved in hydrogen storage materials development through the U.S. Department of Energy’s (DOE) Fuel Cell Technologies Office and the three Hydrogen Storage Materials Centers of Excellence (CoEs), which ran from 2005 to 2010 is presented. The three CoEs were created to develop reversible metal hydrides, chemical hydrogen storage materials, and high-specific-surface-area (SSA) hydrogen sorbents. For each CoE, the approach taken is specified, key outcomes and accomplishments identified, and recommendations for future work are suggested. The Metal Hydride Center of Excellence addresses work on destabilized hydrides, including the LiBH/Mg2NiH4 system, borohydrides, amides, and alanes; and compares the best materials to DOE targets. The Chemical Hydrogen Storage Center of Excellence discusses the classes of materials studied for chemical hydrogen storage, focusing on ammonia borane and examines the progress in developing efficient regeneration schemes. The Hydrogen Sorption Center of Excellence describes the progress in developing high-SSA sorbents and pathways for developing improved materials capable of achieving DOE targets. The phenomenon of spillover is also observed and its importance to ensuring improved measurements is discussed. Through the five-year effort of the Hydrogen Storage Materials Centers of Excellence, significant progress was achieved in developing and understanding hydrogen storage materials.