Showing papers on "Hydrogen storage published in 2013"
TL;DR: In this paper, a state-of-the-art update on the most recent developments concerning the advanced heteroatom doping of carbon that goes beyond nitrogen is given, with respect to their boron-, sulphur-and phosphorus-doping.
Abstract: Heteroatom doped carbon materials represent one of the most prominent families of materials that are used in energy related applications, such as fuel cells, batteries, hydrogen storage or supercapacitors. While doping carbons with nitrogen atoms has experienced great progress throughout the past decades and yielded promising material concepts, also other doping candidates have gained the researchers' interest in the last few years. Boron is already relatively widely studied, and as its electronic situation is contrary to the one of nitrogen, codoping carbons with both heteroatoms can probably create synergistic effects. Sulphur and phosphorus have just recently entered the world of carbon synthesis, but already the first studies published prove their potential, especially as electrocatalysts in the cathodic compartment of fuel cells. Due to their size and their electronegativity being lower than those of carbon, structural distortions and changes of the charge densities are induced in the carbon materials. This article is to give a state of the art update on the most recent developments concerning the advanced heteroatom doping of carbon that goes beyond nitrogen. Doped carbon materials and their applications in energy devices are discussed with respect to their boron-, sulphur- and phosphorus-doping.
1,490 citations
TL;DR: In this paper, an overview of all systems including the current research and potential benefits and issue are provided in the present paper, and a lot of research is invested in finding a compact, safe, reliable, inexpensive and energy efficient method of H2 storage.
655 citations
TL;DR: An efficient low-temperature aqueous-phase methanol dehydrogenation process, which is facilitated by ruthenium complexes is described, which would make the delivery of hydrogen on mobile devices—and hence the use of meethanol as a practical hydrogen carrier—feasible.
Abstract: An efficient, low-temperature, aqueous-phase method of producing hydrogen gas from methanol using ruthenium complexes is described, which could make the transport of hydrogen — and hence its use for clean-energy generation — feasible. Hydrogen is readily converted into energy by PEM (proton-exchange membrane) fuel cells, but its inconvenience when it comes to transport and storage has limited interest in the 'hydrogen economy'. Methanol — 12.6% hydrogen and an easily handled liquid at room temperature — could be the answer to the problem. Matthias Beller and colleagues describe an efficient aqueous-phase methanol dehydrogenation process, catalysed by ruthenium complexes, that could form the basis of a practical hydrogen storage and delivery system. Importantly, because the reaction proceeds at 95 °C or below and at ambient pressures, it allows for the direct use of methanol in PEM fuel cells. Hydrogen produced from renewable resources is a promising potential source of clean energy. With the help of low-temperature proton-exchange membrane fuel cells, molecular hydrogen can be converted efficiently to produce electricity1,2,3,4,5. The implementation of sustainable hydrogen production and subsequent hydrogen conversion to energy is called “hydrogen economy”2. Unfortunately, its physical properties make the transport and handling of hydrogen gas difficult. To overcome this, methanol can be used as a material for the storage of hydrogen, because it is a liquid at room temperature and contains 12.6 per cent hydrogen. However, the state-of-the-art method for the production of hydrogen from methanol (methanol reforming) is conducted at high temperatures (over 200 degrees Celsius) and high pressures (25–50 bar), which limits its potential applications6,7,8. Here we describe an efficient low-temperature aqueous-phase methanol dehydrogenation process, which is facilitated by ruthenium complexes. Hydrogen generation by this method proceeds at 65–95 degrees Celsius and ambient pressure with excellent catalyst turnover frequencies (4,700 per hour) and turnover numbers (exceeding 350,000). This would make the delivery of hydrogen on mobile devices—and hence the use of methanol as a practical hydrogen carrier—feasible.
600 citations
TL;DR: In this paper, the authors summarize and compare recently reported routes for the preparation of nitrogen-containing porous carbon materials and the effect of nitrogen groups on its applications in adsorption, electrochemistry, catalysis/catalyst supports and hydrogen storage properties.
Abstract: Nitrogen-containing porous carbon materials are ubiquitous with a wide range of technologically important applications, including separation science, heterogeneous catalyst supports, water purification, electrochemistry, as well as the developing areas of energy generation and storage applications. To date, a variety of approaches has been developed and applied to introduce nitrogen into the carbon matrix. It is important and necessary to design and control a hierarchical porous structure and the surface chemical groups of nitrogen-containing porous carbons for their applications. In this work, we summarize and compare recently reported routes for the preparation of nitrogen-containing porous carbon materials and the effect of nitrogen groups on its applications in adsorption, electrochemistry, catalysis/catalyst supports and hydrogen storage properties.
596 citations
TL;DR: On-going efforts and studies on functionalized and nanostructured graphene for hydrogen storage are reviewed and possible developments for efficient storage/release of hydrogen under ambient conditions are suggested.
Abstract: Hydrogen-based fuel cells are promising solutions for the efficient and clean delivery of electricity. Since hydrogen is an energy carrier, a key step for the development of a reliable hydrogen-based technology requires solving the issue of storage and transport of hydrogen. Several proposals based on the design of advanced materials such as metal hydrides and carbon structures have been made to overcome the limitations of the conventional solution of compressing or liquefying hydrogen in tanks. Nevertheless none of these systems are currently offering the required performances in terms of hydrogen storage capacity and control of adsorption/desorption processes. Therefore the problem of hydrogen storage remains so far unsolved and it continues to represent a significant bottleneck to the advancement and proliferation of fuel cell and hydrogen technologies. Recently, however, several studies on graphene, the one-atom-thick membrane of carbon atoms packed in a honeycomb lattice, have highlighted the potentialities of this material for hydrogen storage and raise new hopes for the development of an efficient solid-state hydrogen storage device. Here we review on-going efforts and studies on functionalized and nanostructured graphene for hydrogen storage and suggest possible developments for efficient storage/release of hydrogen under ambient conditions.
438 citations
TL;DR: New technology for hydrogen storage broadly covers new technology, ranging from physical media involving solid adsorbents, to chemical materials including metal hydrides, ammonia borane and liquid precursors such as alcohols and formic acid.
389 citations
TL;DR: Using density functional calculations, this work systematically investigated the hydrogen storage properties of the two-dimensional Ti2C phase, which is a representative of the recently synthesized MXene materials and confirmed the hydrogen molecules bound by Kubas-type interaction can be adsorbed and released reversibly under ambient conditions.
Abstract: Searching for reversible hydrogen storage materials operated under ambient conditions is a big challenge for material scientists and chemists. In this work, using density functional calculations, we systematically investigated the hydrogen storage properties of the two-dimensional (2D) Ti2C phase, which is a representative of the recently synthesized MXene materials ( ACS Nano 2012 , 6 , 1322 ). As a constituent element of 2D Ti2C phase, the Ti atoms are fastened tightly by the strong Ti-C covalent bonds, and thus the long-standing clustering problem of transition metal does not exist. Combining with the calculated binding energy of 0.272 eV, ab initio molecular dynamic simulations confirmed the hydrogen molecules (3.4 wt % hydrogen storage capacity) bound by Kubas-type interaction can be adsorbed and released reversibly under ambient conditions. Meanwhile, the hydrogen storage properties of the other two MXene phases (Sc2C and V2C) were also evaluated, and the results were similar to those of Ti2C. Therefore, the MXene family including more than 20 members was expected to be a good candidate for reversible hydrogen storage materials under ambient conditions.
365 citations
344 citations
TL;DR: In this article, the use of milling tools for tuning the microstructure of metals to modify their hydrogenation properties is discussed, and more specialised techniques such as solid/liquid based methods are mentioned along with the common characteristics of mechanochemistry as a way of synthesizing hydrogen storage materials.
332 citations
TL;DR: In this paper, recent progress towards porous carbon-based materials for hydrogen storage is analyzed and reviewed, and strategies for effectively controlling the hydrogen storage capacity and tuning the hydrogen adsorption enthalpy for porous carbon materials via appropriate manipulation of surface area, pore volume and pore size are discussed in detail.
Abstract: The development of highly efficient hydrogen storage materials is one of the main challenges that must be tackled in a widely expected hydrogen economy. Physisorption in porous materials with high surface areas and chemisorption in hydrides are the two main options for solid state hydrogen storage, and both options possess their inherent advantages and drawbacks. In this work, recent progress towards porous carbon-based materials for hydrogen storage is analyzed and reviewed. The hydrogen storage performance of plain porous carbons, metal-supported porous carbons and porous carbons confined hydrides is summarized. Some strategies for effectively controlling the hydrogen storage capacity and tuning the hydrogen adsorption enthalpy for porous carbon materials via appropriate manipulation of surface area, pore volume and pore size are discussed in detail. The new development of porous carbon-based materials for hydrogen storage is particularly emphasized.
310 citations
TL;DR: A novel BN material (i.e., porous microbelts), with the highest specific surface area ever reported for any BN system, is obtained through one-step template-free reaction of a boron acid-melamine precursor with ammonia.
Abstract: Layered boron nitrides (BNs) are usually viewed as excellent protective coatings and reinforcing materials due to their chemical inertness and high mechanical strength. However, the attention paid to their potential applications in gas sorption, especially in case of hydrogen, has obviously been insufficient. Herein, a novel BN material (i.e., porous microbelts), with the highest specific surface area ever reported for any BN system, up to 1488 m2 g–1, is obtained through one-step template-free reaction of a boron acid–melamine precursor with ammonia. Comprehensive high-resolution transmission electron microscopy, X-ray diffraction, and Raman characterizations all confirm that the obtained BN phase is partially disordered, shows an enlarged average spacing between adjacent (0002) layers (d0002 = 0.38 nm, compared to normal 0.33 nm for a bulk layered BN), and belongs to an intermediate state between hexagonal (h-BN) and amorphous (a-BN) phases. By changing the synthesis temperatures, the textures of obtain...
22 Nov 2013
TL;DR: In this paper, the reactivity of the Zn(+2) salt in the growth solution can also markedly affect the size and the morphology of ZIF-8 particles Small Zif-8 nanocrystals with diameters varying between ca 50 and 200 nm were obtained with reactive zinc salts.
Abstract: Metal organic frameworks (MOFs) are porous crystalline materials composed of metal ions or clusters of metal ions coordinated with organic linkers (such as terephthalic acid, 1,3,5-benzenetricarboxylic acid, or imidazoles) MOFs exhibit tunable structures, low density, ultrahigh surface area and have various potential applications in catalysis, hydrogen storage, and adsorption/separation of liquid or gaseous mixtures Among the MOFs structures, the zeolitic imidazolate frameworks (ZIFs) have recently attracted considerable attention In these materials, metal atoms such as Zn2+ are linked through N atoms by the ditopic 2-methylimidazolate ligand to form neutral frameworks ZIF-8 has a sodalite zeolite-type topology with cages of 116 A and pores of 34 A in diameter ZIF-8 are characterized by high thermal stability (550 oC in N2), large surface area (BET: 1630 m2/g) and high resistance to various solvents Concerning ZIF-8 chemical properties, these materials can successfully be used for hydrogen, carbon dioxide and iodide storage, Knoevenagel condensations, cycloadditions, oxidations, trans-esterification, and Friedel-Crafts alkylations Variations of synthetic parameters (solvent, concentration, temperature, time, molar ratio of reactants) are commonly used to manipulate the morphology and size of ZIF-8 crystals In this work, we demonstrate that the reactivity of the Zn(+2) salt in the growth solution can also markedly affect the size and the morphology of ZIF-8 particles Small ZIF-8 nanocrystals with diameters varying between ca 50 and 200 nm were obtained with reactive zinc salts like Zn(acac)2, Zn(NO3)2, ZnSO4 or Zn(ClO4)2 The use of ZnCl2, Zn(OAc)2 or ZnI2 afforded crystals with sizes varying between ca 350 and 650 nm Finally, the low reactive ZnBr2 was found to generate microsized crystals These significant changes in particle size induced distinctive changes in adsorption properties as demonstrated by BET measurements but also in the catalytic performances of ZIF-8 crystals in a Knoevenagel condensation used as model The small sized crystals produced from Zn(NO3)2 exhibit the highest surface area and the best catalytic activity
TL;DR: In this article, the composites based on Cu-BTC and graphene layers were prepared with different percentages of graphene oxide (GO) through characterization analyses and gas adsorption experiments, and they found that the nanosized and well-dispersed Cu- BTC induced by the incorporation of GO greatly improved the carbon dioxide capture and hydrogen storage performance of composites.
Abstract: Various MOFs with tailored nanoporosities have recently been developed as potential storage media for CO2 and H2. The composites based on Cu-BTC and graphene layers were prepared with different percentages of graphene oxide (GO). Through the characterization analyses and gas adsorption experiments, we found that the nanosized and well-dispersed Cu-BTC induced by the incorporation of GO greatly improved the carbon dioxide capture and hydrogen storage performance of the composites. The materials obtained exhibited about a 30% increase in CO2 and H2 storage capacity (from 6.39 mmol g−1 of Cu-BTC to 8.26 mmol g−1 of CG-9 at 273 K and 1 atm for CO2; from 2.81 wt% of Cu-BTC to 3.58 wt% of CG-9 at 77 K and 42 atm for H2). Finally, the CO2/CH4 and CO2/N2 selectivities were calculated according to single-component gas sorption experiment data.
TL;DR: In this paper, the authors employed data mining and automated structure analysis to identify, cleanup, and rapidly predict the hydrogen storage properties of metal-organic frameworks (MOFs) with respect to their surface area and porosity.
Abstract: Because of their high surface areas, crystallinity, and tunable properties, metal–organic frameworks (MOFs) have attracted intense interest as next-generation materials for gas capture and storage. While much effort has been devoted to the discovery of new MOFs, a vast catalog of existing MOFs resides within the Cambridge Structural Database (CSD), many of whose gas uptake properties have not been assessed. Here we employ data mining and automated structure analysis to identify, “cleanup,” and rapidly predict the hydrogen storage properties of these compounds. Approximately 20 000 candidate compounds were generated from the CSD using an algorithm that removes solvent/guest molecules. These compounds were then characterized with respect to their surface area and porosity. Employing the empirical relationship between excess H2 uptake and surface area, we predict the theoretical total hydrogen storage capacity for the subset of ∼4000 compounds exhibiting nontrivial internal porosity. Our screening identifies...
TL;DR: Mg2In0.1Ni solid solution with an Mg2Ni-type structure has been synthesized and its hydrogen storage properties have been investigated in this paper, where the authors showed that the introduction of In into Mg 2Ni not only significantly improved the dehydrogenation kinetics but also greatly lowered the thermodynamic stability.
TL;DR: The synthesis of high-quality microporous/mesoporous BN material via a facile two-step approach is reported on, showing excellent hydrogen uptake capacity of the BN whiskers with high weight adsorption up to 5.6% at room temperature and at the relatively low pressure of 3 MPa.
Abstract: We report on the synthesis of high-quality microporous/mesoporous BN material via a facile two-step approach. An extremely high surface area of 1687?m2?g?1 and a large pore volume of 0.99?cm3?g?1 have been observed in the synthesized BN porous whiskers. The formation of the porous structure was attributed to the group elimination of organic species in a BN precursor, melamine diborate molecular crystal. This elimination method maintained the ordered pore structure and numerous structural defects. The features including high surface area, pore volume and structural defects make the BN whiskers highly suitable for hydrogen storage and wastewater treatment applications. We demonstrate excellent hydrogen uptake capacity of the BN whiskers with high weight adsorption up to 5.6% at room temperature and at the relatively low pressure of 3?MPa. Furthermore, the BN whiskers also exhibit excellent adsorption capacity of methyl orange and copper ions, with the maximum removal capacity of 298.3 and 373?mg?g?1 at 298?K, respectively.
TL;DR: The efficient and selective hydrogen liberation from formic acid is catalyzed by an iron pincer complex in the presence of trialkylamine and turnover numbers up to 100,000 were achieved at 40 °C.
Abstract: Hydrogen liberation: An attractive approach to reversible hydrogen storage applications is based on the decomposition of formic acid. The efficient and selective hydrogen liberation from formic acid is catalyzed by an iron pincer complex in the presence of trialkylamine. Turnover frequencies up to 836 h⁻¹ and turnover numbers up to 100,000 were achieved at 40 °C. A mechanism including well-defined intermediates is suggested on the basis of experimental and computational data.
TL;DR: In this paper, the ZrTiVCrFeNi high entropy alloy was successfully synthesized from elemental powders near the equimolar ratio using Laser Engineered Net Shaping (LENS).
TL;DR: In this review article, the fundamentals of electrochemical reactions involving metal hydrides are explained, followed by a report of recent progress in hydrogen storage alloys for electrochemical applications.
Abstract: In this review article, the fundamentals of electrochemical reactions involving metal hydrides are explained, followed by a report of recent progress in hydrogen storage alloys for electrochemical applications. The status of various alloy systems, including AB₅, AB₂, A₂B₇-type, Ti-Ni-based, Mg-Ni-based, BCC, and Zr-Ni-based metal hydride alloys, for their most important electrochemical application, the nickel metal hydride battery, is summarized. Other electrochemical applications, such as Ni-hydrogen, fuel cell, Li-ion battery, air-metal hydride, and hybrid battery systems, also have been mentioned.
TL;DR: Using first-principles calculations based on density functional theory, the authors showed that graphitic carbon nitride (g-C4N3 and g-C3N4) can be functionalized with Li atoms for use as materials not only for high capacity hydrogen storage but also for lithium-ion batteries.
Abstract: Using first-principles calculations based on density functional theory, we show that recently synthesized graphitic carbon nitride (g-C4N3 and g-C3N4) can be functionalized with Li atoms for use as materials not only for high-capacity hydrogen storage but also for lithium-ion batteries. The unique properties are due to the high density of Li ions firmly adsorbed over nitrogen triangular holes. The gravimetric and volumetric densities of hydrogen in Li2C3N4 and Li2C4N3 are greater than 10 wt % and 100 g/L, respectively, both exceeding the target set by the U.S. Department of Energy. Similarly, single-layer Li2C3N4 is a good candidate for a lithium-ion anode material with a specific capacity almost twice that of graphite, and bulk LiC4N3 can be used as a cathode material with a specific energy twice that of LiCoO2. The materials have the added advantage that they are stable against clustering of Li and are nontoxic.
TL;DR: Well-dispersed magnetically recyclable core-shell Ag@M (M = Co, Ni, Fe) nanoparticles supported on graphene have been synthesized via a facile in situ one-step procedure, indicating that MeAB could be used as not only a potential hydrogen storage material but also an efficient reducing agent.
Abstract: Well-dispersed magnetically recyclable core–shell Ag@M (M = Co, Ni, Fe) nanoparticles (NPs) supported on graphene have been synthesized via a facile in situ one-step procedure, using methylamine borane (MeAB) as a reducing agent under ambient condition. Their catalytic activity toward hydrolysis of ammonia borane (AB) were studied. Although the Ag@Fe/graphene NPs are almost inactive, the as-prepared Ag@Co/graphene NPs are the most reactive catalysts, followed by Ag@Ni/graphene NPs. Compared with AB and NaBH4, the as-synthesized Ag@Co/graphene catalysts which reduced by MeAB exert the highest catalytic activity. Additionally, the Ag@Co NPs supported on graphene exhibit higher catalytic activity than the catalysts with other conventional supports, such as the SiO2, carbon black, and γ-Al2O3. The as-synthesized Ag@Co/graphene NPs exert satisfied catalytic activity, with the turnover frequency (TOF) value of 102.4 (mol H2 min–1 (mol Ag)−1), and the activation energy Ea value of 20.03 kJ/mol. Furthermore, the ...
TL;DR: In this article, a series of new Cu 1− x Fe x alloy nanoparticles (NPs) have been successfully in situ synthesized by a very simple method and used as catalysts for hydrogen generation from the aqueous solution of ammonia borane (AB) under ambient atmosphere at room temperature.
TL;DR: Based on the current progress, finding reversible systems with high hydrogen capacity and effectively tailored reaction enthalpy offers a promising route for tuning the thermodynamics of Mg-based hydrogen storage alloys.
Abstract: Mg-based hydrides are one of the most promising hydrogen storage materials because of their relatively high storage capacity, abundance, and low cost. However, slow kinetics and stable thermodynamics hinder their practical application. In contrast to the substantial progress in the enhancement of the hydrogenation/dehydrogenation kinetics, thermodynamic tuning is still a great challenge for Mg-based alloys. At present, the main strategies to alter the thermodynamics of Mg/MgH2 are alloying, nanostructuring, and changing the reaction pathway. Using these approaches, thermodynamic tuning has been achieved to some extent, but it is still far from that required for practical application. In this article, we summarize the advantages and disadvantages of these strategies. Based on the current progress, finding reversible systems with high hydrogen capacity and effectively tailored reaction enthalpy offers a promising route for tuning the thermodynamics of Mg-based hydrogen storage alloys.
TL;DR: A series of Ti-based intermetallic alloy (TiAl, Ti3Al,TiNi, TiFe, TiNb, TiMn2, and TiVMn)-doped MgH2 materials were systematically investigated in this paper to improve its hydrogen storage properties.
Abstract: Magnesium hydride is a promising candidate for solid-state hydrogen storage and thermal energy storage applications. A series of Ti-based intermetallic alloy (TiAl, Ti3Al, TiNi, TiFe, TiNb, TiMn2, and TiVMn)-doped MgH2 materials were systematically investigated in this study to improve its hydrogen storage properties. The dehydrogenation and hydrogenation properties were studied by using both thermogravimetric analysis and pressure–composition–temperature (PCT) isothermal to characterize the temperature of dehydrogenation and the kinetics of both desorption and absorption of hydrogen by these doped MgH2. Results show significant improvements of both dehydrogenation and hydrogenation kinetics as a result of adding the Ti intermetallic alloys as catalysts. In particular, the TiMn2-doped Mg demonstrated extraordinary hydrogen absorption capability at room temperature and 1 bar hydrogen pressure. The PCT experiments also show that the hydrogen equilibrium pressures of MgH2 were not affected by these additives.
TL;DR: In this article, metal aluminum activated by various techniques, namely by the addition of alkaline solutions, carbon materials, oxides and by alloying with other elements, are summarized.
TL;DR: Interestingly, the theoretical study has identified that the Zn-based analogs would be expected to facilitate enhanced adsorption profiles over the compounds synthesized experimentally, highlighting the importance of a combined experimental and theoretical approach to the design and synthesis of new frameworks for H(2) storage applications.
Abstract: Microporous metal–organic frameworks are a class of materials being vigorously investigated for mobile hydrogen storage applications. For high-pressure storage at ambient temperatures, the M3[(M4Cl)3(BTT)8]2 (M-BTT; BTT3– = 1,3,5-benzenetristetrazolate) series of frameworks are of particular interest due to the high density of exposed metal cation sites on the pore surface. These sites give enhanced zero-coverage isosteric heats of adsorption (Qst) approaching the optimal value for ambient storage applications. However, the Qst parameter provides only a limited insight into the thermodynamics of the individual adsorption sites, the tuning of which is paramount for optimizing the storage performance. Here, we begin by performing variable-temperature infrared spectroscopy studies of Mn-, Fe-, and Cu-BTT, allowing the thermodynamics of H2 adsorption to be probed experimentally. This is complemented by a detailed DFT study, in which molecular fragments representing the metal clusters within the extended solid...
TL;DR: The results indicate that the activation step not only creates a porous structure, but also introduces various phosphorus and oxygen functional groups to the surface of carbons to widen the potential window above the theoretical potential for the decomposition of water.
Abstract: Phosphorus-rich carbons (PCs) were prepared by phosphoric acid activation of waste coffee grounds in different impregnation ratios. PCs were characterized by nitrogen and carbon dioxide adsorption and X-ray photoelectron spectroscopy. The results indicate that the activation step not only creates a porous structure, but also introduces various phosphorus and oxygen functional groups to the surface of carbons. As evidenced by cyclic voltammetry, galvanostatic charge/discharge, and wide potential window tests, a supercapacitor constructed from PC-2 (impregnation ratio of 2), with the highest phosphorus content, can operate very stably in 1 M H2SO4 at 1.5V with only 18 % degradation after 10 000cycles at a current density of 5A g-1. Due to the wide electrochemical window, a supercapacitor assembled with PC-2 has a high energy density of 15Wh kg-1 at a power density of 75W kg -1. The possibility of widening the potential window above the theoretical potential for the decomposition of water is attributed to reversible electrochemical hydrogen storage in narrow micropores and the positive effect of phosphorus-rich functional groups, particularly the polyphosphates on the carbon surface. Rich pick-me-up! Waste coffee grounds are used to synthesize phosphorus-rich carbons (PCs), which show intriguing properties as electrode materials of an acidic supercapacitor. Large potentials can be applied, owing to the stabilizing effect of phosphorus on the carbon surface and reversible electrochemical hydrogen storage in pores of the PC. Copyright
TL;DR: In this paper, a review of the potential of boron-based hydrides in chemical hydrogen storage is presented, but their implementation depends on the recyclability of the solid by-products.
Abstract: SUMMARY
The development of the hydrogen economy is hampered by many issues connected with production, storage, distribution, and end-use. Although the hydrogen storage problem is particularly difficult, there are several attractive solutions under investigation, and chemical hydrogen storage (involving hydrogen-rich materials) has shown much promising properties. The boron-based materials are typical examples. They have high hydrogen densities, with up to four reactive B − H bonds. Most of the works have focused on dehydrogenation by hydrolysis or thermolysis so that it takes place in high extent in mild conditions. The first materials studied have been lithium borohydride, sodium borohydride, and ammonia borane. However, their development has been hindered by technical issues such as very high dehydrogenation temperatures, incomplete reaction, and purity of the produced hydrogen. To get round such problems, new materials have been proposed since the mid-2000s. Interestingly, those materials present attractive attributes, but also drawbacks. This is illustrated in the present review. We believe that boron-based hydrides have a significant potential in chemical hydrogen storage, but their implementation depends on the recyclability of the solid by-products; this seems to be the key factor. Copyright © 2013 John Wiley & Sons, Ltd.
TL;DR: In this paper, a platinum-modified Ni/Al2O3 catalysts were tested in the decomposition of hydrous hydrazine to H2 with a high selectivity and a high activity under mild conditions.
TL;DR: In this article, Ru nanoparticles supported on graphene have been synthesized via a one-step procedure using methylamine borane as reducing agent, and the as-prepared Ru/graphene NPs reduced by methyl-lamine-borane exhibit superior catalytic activity towards the hydrolytic dehydrogenation of ammonia boreane.