Showing papers on "Hydrogen storage published in 2015"
TL;DR: In this paper, recent developments in the production of hydrogen fuel, applications and storage together with the environmental impacts of hydrogen as energy carrier are emphasized. But, storage remains a big challenge.
Abstract: Transportation of people and commodities being a socio-economic criterion needs clean energy and the demand is kept on increasing with modernization. Consequently, generation of a fuel with safer, efficient, economic and reasonably environmental friendly features is the key issue towards fulfilling such demands. Hydrogen seems to be an ideal synthetic energy carrier due to its lightweight, exclusive abundance and environmentally benign oxidation product (water). However, storage remains a big challenge. In this communication, recent developments in the production of hydrogen fuel, applications and storage together with the environmental impacts of hydrogen as energy carrier are emphasized.
666 citations
TL;DR: A review of the research progress in the development of diverse liquid-phase chemical hydrogen storage materials, including organic and inorganic chemical hydrides, with emphases on the syntheses of active catalysts for catalytic hydrogen generation and storage is presented in this paper.
Abstract: The search for hydrogen storage materials capable of efficiently storing hydrogen in a compact and lightweight package is one of the most difficult challenges for the upcoming hydrogen economy. Liquid chemical hydrides with high gravimetric and volumetric hydrogen densities have the potential to overcome the challenges associated with hydrogen storage. Moreover, the liquid-phase nature of these hydrogen storage systems provides significant advantages of easy recharging, and the availability of the current liquid fuel infrastructure for recharging. In this review, we briefly survey the research progress in the development of diverse liquid-phase chemical hydrogen storage materials, including organic and inorganic chemical hydrides, with emphases on the syntheses of active catalysts for catalytic hydrogen generation and storage. Moreover, the advantages and drawbacks of each storage system are discussed.
617 citations
TL;DR: In this article, a review focusing on various hydrogen producing and storing methods that can be employed for creating a hydrogen economy is presented, where the latest advancements that have been made on different hydrogen storing materials and hydrogen storing technologies which have proven useful both on gravimetric and volumetric basis, have been highlighted.
Abstract: The review focuses on various hydrogen producing and storing methods that can be employed for creating a hydrogen economy. The latest advancements that have been made on different hydrogen storing materials and hydrogen storing technologies which have proven useful both on gravimetric and volumetric basis, have been highlighted. The encouraging and hopeful aspect of their developments is that the most of the materials are approaching the hydrogen storing capacity requirement that have been laid down by DOE. The classification of different systems has been done on basis of their storage mechanism, keeping in mind their advantages and disadvantages while they tend to store hydrogen both in the atomic and molecular form.
606 citations
TL;DR: A wide variety of graphene related materials have been synthesized for potential applications in electronics, energy storage, catalysis, and gas sorption, storage, separation and sensing as discussed by the authors.
574 citations
TL;DR: In this article, the authors present the recent developments in the field of production, storage, transport and delivery of hydrogen along with environmental and safety aspects of its use as an energy carrier.
Abstract: Mobility (transport of people and goods) is a socio-economic reality and need for which is bound to grow in the coming years. Modes of transport should be safe, economic and reasonably environmental friendly. Hydrogen could be ideal as a synthetic energy carrier for transport sector as its gravimetric energy density is very high, abundantly available in combined form on the earth and its oxidation product (water) does not contribute to greenhouse gas emissions. However, its sustainable production from renewable resources economically, on-board storage to provide desirable driving range, usage in durable energy conversion devices and development of infrastructure for its delivery remain significant challenges. In this article, recent developments in the field of production, storage, transport and delivery of hydrogen along with environmental and safety aspects of its use as an energy carrier are presented. Almost any energy source can be used to produce hydrogen. Presently, non-renewable sources dominate hydrogen production processes but the need of the hour is to develop and promote the share of renewable sources for hydrogen production to make it completely sustainable. Hydrogen may be used as fuel for almost any application, where fossil fuels are used presently and would offer immediate benefits over the conventional fuels, if produced from renewable sources. For achieving a successful "hydrogen economy" in the near future, the technical and economic challenges associated with hydrogen must be addressed quickly. Finding feasible solutions to different challenges may take some time but technological breakthrough by way of on-going efforts do promise hydrogen as the ultimate solution for meeting our future energy needs for the transport sector.
433 citations
TL;DR: In this article, various types of direct ethanol fuel cells are reviewed with emphasis on ethanol sources and production methods, cell construction materials, operating regime, cell and stack fabrication, performance and life time issues, technology status and market applications.
382 citations
TL;DR: Recent developments in effective high-capacity hydrogen storage materials are reviewed, with a special emphasis on light compounds, including those based on organic porous structures, boron, nitrogen, and aluminum.
Abstract: One of the limitations to the widespread use of hydrogen as an energy carrier is its storage in a safe and compact form. Herein, recent developments in effective high-capacity hydrogen storage materials are reviewed, with a special emphasis on light compounds, including those based on organic porous structures, boron, nitrogen, and aluminum. These elements and their related compounds hold the promise of high, reversible, and practical hydrogen storage capacity for mobile applications, including vehicles and portable power equipment, but also for the large scale and distributed storage of energy for stationary applications. Current understanding of the fundamental principles that govern the interaction of hydrogen with these light compounds is summarized, as well as basic strategies to meet practical targets of hydrogen uptake and release. The limitation of these strategies and current understanding is also discussed and new directions proposed.
297 citations
TL;DR: In this paper, a review of the development of catalytic additives and their effect on the activation energy, kinetics and thermodynamic properties of magnesium hydride is presented, with a focus on the effect of different additives on the activated energy and kinetics of the pure material.
234 citations
TL;DR: A new class of low-cost catalytic system that uses nanostructured Ni2 P as catalyst, which exhibits excellent catalytic activity and high sustainability toward hydrolysis of ammonia-borane with the initial turnover frequency.
Abstract: Ammonia–borane (AB) is a promising chemical hydrogen-storage material. However, the development of real-time, efficient, controllable, and safe methods for hydrogen release under mild conditions is a challenge in the large-scale use of hydrogen as a long-term solution for future energy security. A new class of low-cost catalytic system is presented that uses nanostructured Ni2P as catalyst, which exhibits excellent catalytic activity and high sustainability toward hydrolysis of ammonia–borane with the initial turnover frequency of 40.4 mol(H2) mol(Ni2P)−1 min−1 under air atmosphere and at ambient temperature. This value is higher than those reported for noble-metal-free catalysts, and the obtained Arrhenius activation energy (Ea=44.6 kJ mol−1) for the hydrolysis reaction is comparable to Ru-based bimetallic catalysts. A clearly mechanistic analysis of the hydrolytic reaction of AB based on experimental results and a density functional theory calculation is presented.
197 citations
TL;DR: A review of catalysts for aqueous NaBH4 can be found in this paper, which summarizes the various catalysts which have been reported in the literature for the hydrolysis of NaH4.
Abstract: It is clear that in order to satisfy global energy demands whilst maintaining sustainable levels of atmospheric greenhouse gases, alternative energy sources are required. Due to its high chemical energy density and the benign by-product of its combustion reactions, hydrogen is one of the most promising of these. However, methods of hydrogen storage such as gas compression or liquefaction are not suitable for portable or automotive applications due to their low hydrogen storage densities. Accordingly, much research activity has been focused on finding higher density hydrogen storage methods. One such method is to generate hydrogen via the hydrolysis of aqueous sodium borohydride (NaBH4) solutions, and this has been heavily studied since the turn of the century due to its high theoretical hydrogen storage capacity (10.8 wt%) and relatively safe operation in comparison to other chemical hydrides. This makes it very attractive for use as a hydrogen generator, in particular for portable applications. Major factors affecting the hydrolysis reaction of aqueous NaBH4 include the performance of the catalyst, reaction temperature, NaBH4 concentration, stabilizer concentration, and the volume of the reaction solution. Catalysts based on noble metals, in particular ruthenium (Ru) and platinum (Pt), have been shown to be particularly efficient at rapid generation of hydrogen from aqueous NaBH4 solutions. However, given the scarcity and expense of such metals, a transition metal-based catalyst would be a desirable alternative, and thus much work has been conducted using cobalt (Co) and nickel (Ni)-based materials to attempt to source a practical option. “Metal free” NaBH4 hydrolysis can also be achieved by the addition of aqueous acids such as hydrochloric acid (HCl) to solid NaBH4. This review summarizes the various catalysts which have been reported in the literature for the hydrolysis of NaBH4.
195 citations
TL;DR: The new covalent organic framework material combines permanent micropores, high crystallinity, good thermal and chemical stability, and abundant heteroatom activated sites in the skeleton to exhibit remarkable carbon dioxide uptake and methane uptake and high CO2 /N2 selectivity.
Abstract: A azine-linked covalent organic framework, COF-JLU2, was designed and synthesized by condensation of hydrazine hydrate and 1,3,5-triformylphloroglucinol under solvothermal conditions for the first time. The new covalent organic framework material combines permanent micropores, high crystallinity, good thermal and chemical stability, and abundant heteroatom activated sites in the skeleton. COF-JLU2 possesses a moderate BET surface area of over 410 m(2) g(-1) with a pore volume of 0.56 cm(3) g(-1) . Specifically, COF-JLU2 displays remarkable carbon dioxide uptake (up to 217 mg g(-1) ) and methane uptake (38 mg g(-1) ) at 273 K and 1 bar, as well as high CO2 /N2 (77) selectivity. Furthermore, we further highlight that it exhibits a higher hydrogen storage capacity (16 mg g(-1) ) than those of reported COFs at 77 K and 1 bar.
TL;DR: In this article, it was shown that confining LiBH4 in the pores of ordered mesoporous silica scaffolds leads to high Li+ conductivity (0.1 mS cm(-1)) at room temperature.
Abstract: Designing new functional materials is crucial for the development of efficient energy storage and conversion devices such as all solid-state batteries. LiBH4 is a promising solid electrolyte for Li-ion batteries. It displays high lithium mobility, although only above 110 degrees C at which a transition to a high temperature hexagonal structure occurs. Herein, it is shown that confining LiBH4 in the pores of ordered mesoporous silica scaffolds leads to high Li+ conductivity (0.1 mS cm(-1)) at room temperature. This is a surprisingly high value, especially given that the nanocomposites comprise 42 vol% of SiO2. Solid state Li-7 NMR confirmed that the high conductivity can be attributed to a very high Li+ mobility in the solid phase at room temperature. Confinement of LiBH4 in the pores leads also to a lower solid-solid phase transition temperature than for bulk LiBH4. However, the high ionic mobility is associated with a fraction of the confined borohydride that shows no phase transition, and most likely located close to the interface with the SiO2 pore walls. These results point to a new strategy to design low-temperature ion conducting solids for application in all solid-state lithium ion batteries, which could enable safe use of Li-metal anodes.
TL;DR: In this article, the main problems of high air pollution levels at many urban cities and sustainability of the transportation fuels, and addressing their control measures using hydrogen energy system are reviewed and analyzed for the road transportation sector.
Abstract: This study reviews the main problems of high air pollution levels at many urban cities and sustainability of the transportation fuels, and addressing their control measures using hydrogen energy system. In the world, majority of the transportation vehicle fleets consume the fuels derived from fossil resources. The development of economy activities indicate the increase in transportation services resulting in increased fuel consumption and high emissions, especially unregulated emission carbon dioxide, which is a greenhouse gas (GHG). Therefore, utilization of hydrogen as fuel in vehicle fleet would improve energy security and reduce the GHG emission. A feasibility of hydrogen energy system, which includes its resources, production technologies, storage, fuel transportation, dispensing and utilization, is analysed for the road transportation sector. In addition to this, the study highlights the technical issues and its control strategy for addressing the problems of the transportation system using the hydrogen. Moreover, hydrogen is the cleanest fuel, especially when coupled with renewable energy sources. The road transportation sector with hydrogen energy system would give the desirable results including high energy efficiency and zero carbon based emission (CO, CO 2 , HC, PM) resulting in strengthening of sustainability of the system. The Governments of many countries have made ambitious policies and provide strong financial support to research organizations including universities and institutions for development of hydrogen energy system. Many companies express strong interest in the commercialization of hydrogen fuelled vehicles either internal combustion engines based, fuel cell based or hybrid technology.
TL;DR: In this paper, a pincer-supported Fe compound and a co-catalytic amount of a Lewis acid were used to catalyze base-free aqueous phase methanol dehydrogenation with turnover numbers up to 51,000.
Abstract: Hydrogen is an attractive alternative energy vector to fossil fuels if effective methods for its storage and release can be developed. In particular, methanol, with a gravimetric hydrogen content of 12.6%, is a promising target for chemical hydrogen storage. To date, there are relatively few homogeneous transition metal compounds that catalyze the aqueous phase dehydrogenation of methanol to release hydrogen and carbon dioxide. In general, these catalysts utilize expensive precious metals and require a strong base. This paper shows that a pincer-supported Fe compound and a co-catalytic amount of a Lewis acid are capable of catalyzing base-free aqueous phase methanol dehydrogenation with turnover numbers up to 51 000. This is the highest turnover number reported for either a first-row transition metal or a base-free system. Additionally, this paper describes preliminary mechanistic experiments to understand the reaction pathway and propose a stepwise process, which requires metal–ligand cooperativity. This...
TL;DR: In this article, non-noble bimetallic CuCo alloy nanoparticles (NPs) were successfully encapsulated in the pores of MIL-101 by using the double-solvent method combined with the overwhelming reduction approach.
TL;DR: In this article, an overview of metal-organic frameworks (MOF) materials processing towards system integration is provided with an emphasis on improving selected properties including (i) structural stability, (ii) thermal conductivity and (iii) hydrogen storage properties.
Abstract: SUMMARY Development of safe and effective hydrogen storage systems is critical for further implementation of hydrogen in fuel cell technologies. Amongst the various approaches to improve the performance of such systems, porous materials-based adsorptive hydrogen storage is envisaged as a long-term solution because of the excellent reversibility, good kinetics and the possibility to store hydrogen at low pressures. Metal–organic frameworks (MOFs) have attracted much attention as porous hydrogen storage materials in the transition from the laboratory to commercial applications. However, MOF materials are often obtained as loose powders with low packing densities and low thermal conductivities. Therefore, to facilitate this transition and enable the MOF materials to form part of a practical hydrogen storage system, knowledge of the ‘processing’ techniques to improve the properties of the powders is essential. However, the processing routes of MOF materials towards system integration are rarely reviewed in the literature although this is of great significance in their proper assessment and potential use for hydrogen storage on a commercial scale. In this review, we begin by introducing the general requirements of an MOF materials-based hydrogen storage system and present how these requirements translate into desired characteristics for further processing. Then, an overview of MOF materials processing towards system integration is provided with an emphasis on improving selected properties including (i) structural stability, (ii) thermal conductivity and (iii) hydrogen storage properties. Copyright © 2014 John Wiley & Sons, Ltd.
TL;DR: In this paper, the authors comprehensively reviewed different strategies to overcome the key barriers of high desorption temperature and low kinetics, especially on the recent approaches of nanosizing and interfacial confinement.
Abstract: Hydrogen storage is now the “bottle neck” to realize application of hydrogen as the renewable energy. The breakthrough in hydrogen storage is quite urgent. Magnesium is a promising candidate for hydrogen storage that attracts tremendous interest in last a few decades and significant progress has been made in recent years. Accordingly, in this article, we comprehensively reviewed different strategies to overcome the key barriers of high desorption temperature and low kinetics, especially on the recent approaches of nanosizing and interfacial confinement. We also try to give our own point of view on the future perspectives of research in Mg for hydrogen storage.
TL;DR: In this article, the authors demonstrate how ammonia can be produced at ambient pressure from air, water, and concentrated sunlight as renewable source of process heat via nitrogen reduction with a looped metal nitride, followed by separate hydrogenation of the lattice nitrogen into ammonia.
Abstract: The activity of many heterogeneous catalysts is limited by strong correlations between activation energies and adsorption energies of reaction intermediates. Although the reaction is thermodynamically favourable at ambient temperature and pressure, the catalytic synthesis of ammonia (NH3), a fertilizer and chemical fuel, from N2 and H2 requires some of the most extreme conditions of the chemical industry. We demonstrate how ammonia can be produced at ambient pressure from air, water, and concentrated sunlight as renewable source of process heat via nitrogen reduction with a looped metal nitride, followed by separate hydrogenation of the lattice nitrogen into ammonia. Separating ammonia synthesis into two reaction steps introduces an additional degree of freedom when designing catalysts with desirable activation and adsorption energies. We discuss the hydrogenation of alkali and alkaline earth metal nitrides and the reduction of transition metal nitrides to outline a promoting role of lattice hydrogen in ammonia evolution. This is rationalized via electronic structure calculations with the activity of nitrogen vacancies controlling the redox-intercalation of hydrogen and the formation and hydrogenation of adsorbed nitrogen species. The predicted trends are confirmed experimentally with evolution of 56.3, 80.7, and 128 μmol NH3 per mol metal per min at 1 bar and above 550 °C via reduction of Mn6N2.58 to Mn4N and hydrogenation of Ca3N2 and Sr2N to Ca2NH and SrH2, respectively.
TL;DR: In this article, the liquid organic hydrogen carriers (LOHC) with high hydrogen contents, reversibilities and moderate dehydrogenation kinetics have been considered as an alternative option supplementing the extensively investigated inorganic hydride systems.
TL;DR: In this paper, the current state-of-the-art and progress over the past three years on the development of hybrid 2D nanomaterials are summarized and discussed. And the challenges and opportunities for the exploration of 2D layered hybrid materials are put forward.
TL;DR: In this article, the effects of high-energy ball-milling on catalyst morphology and dispersion as a function of milling duration and on hydrogen desorption were investigated.
TL;DR: In this paper, the effect of microstructure on the activation of TiFe for hydrogen storage by severe plastic deformation (SPD) through ball milling technique was investigated and it was shown that the activation is easier and the hydrogen pressure for activation is smaller, when the grain size is smaller.
TL;DR: In this paper, a series of bio-inspired Ir complexes for highly robust and selective hydrogen production from formic acid (FA) in aqueous solutions without organic solvents or additives were reported.
Abstract: Hydrogen generation from formic acid (FA), one of the most promising hydrogen storage materials, has attracted much attention due to the demand for the development of renewable energy carriers. Catalytic dehydrogenation of FA in an efficient and green manner remains challenging. Here, we report a series of bioinspired Ir complexes for highly robust and selective hydrogen production from FA in aqueous solutions without organic solvents or additives. One of these complexes bearing an imidazoline moiety (complex 6) achieved a turnover frequency (TOF) of 322 000 h–1 at 100 °C, which is higher than ever reported. The novel catalysts are very stable and applicable in highly concentrated FA. For instance, complex 3 (1 μmol) affords an unprecedented turnover number (TON) of 2 050 000 at 60 °C. Deuterium kinetic isotope effect experiments and density functional theory (DFT) calculations employing a “speciation” approach demonstrated a change in the rate-determining step with increasing solution pH. This study prov...
TL;DR: In this article, the shape of Zr-MOF powder material into spherical pellets with diameters of 0.5-15mm in the presence of 10% sucrose as a binder was successfully demonstrated using a granulator.
TL;DR: In this article, the authors examined combustion stability and emissions from gaseous ammonia blended with methane or hydrogen in gas======turbines and found that efficient combustion can be achieved with high power but at very narrow equivalence ratios using both hydrogen and methane======blends.
TL;DR: The iron complex [FeH(CO) (PNP = N(CH2CH2PiPr2)2) is a highly active catalyst for ammonia borane dehydrocoupling at room temperature as mentioned in this paper.
Abstract: The iron complex [FeH(CO) (PNP)] (PNP = N(CH2CH2PiPr2)2) is a highly active catalyst for ammonia borane dehydrocoupling at room temperature. Mainly linear polyaminoborane is obtained upon release of 1 equiv of H2. Mechanistic studies suggest that both hydrogen release and B–N coupling are metal-catalyzed and proceed via free aminoborane. Catalyst deactivation results from reaction with free BH3 that is formed by aminoborane rearrangement. Importantly, borane trapping with a simple amine allows for the observation of a TON that is unprecedented for a well-defined base metal catalyst.
TL;DR: In this paper, a prototype scale apparatus for screening materials under dynamic conditions with active heat extraction was designed and constructed, where metal hydride was thermally cycled up to 420°C more than 20 times with a minimal loss in hydrogen capacity.
TL;DR: In this paper, 2.4-nm Rh nanoparticles supported on graphene have been synthesized via a one-step in situ procedure by using methylamine borane (MeAB) as the reducing agent.
TL;DR: In this article, a novel energy dispatching based on Model Predictive Control (MPC) for off-grid photovoltaic (PV)/wind turbine/hydrogen/battery hybrid systems is presented.
TL;DR: A defect-engineered self-assembly procedure is reported to produce a three-dimensionally nanohole-structured and palladium-embedded porous graphene hetero-nanostructure having ultrahigh hydrogen storage and CO oxidation multifunctionalities, resulting in a pathway to nanoengineering based on underlying atomic scale and physical defects.
Abstract: Atomic-scale defects on carbon nanostructures have been considered as detrimental factors and critical problems to be eliminated in order to fully utilize their intrinsic material properties such as ultrahigh mechanical stiffness and electrical conductivity. However, defects that can be intentionally controlled through chemical and physical treatments are reasonably expected to bring benefits in various practical engineering applications such as desalination thin membranes, photochemical catalysts, and energy storage materials. Herein, we report a defect-engineered self-assembly procedure to produce a three-dimensionally nanohole-structured and palladium-embedded porous graphene hetero-nanostructure having ultrahigh hydrogen storage and CO oxidation multifunctionalities. Under multistep microwave reactions, agglomerated palladium nanoparticles having diameters of ∼10 nm produce physical nanoholes in the basal-plane structure of graphene sheets, while much smaller palladium nanoparticles are readily impreg...