Improved hydrogen storage kinetics of nanoconfined LiBH4-MgH2 reactive hydride composites catalyzed with nickel Nanoparticles

2012 ◽  
Vol 1441 ◽  
Author(s):  
Thomas K. Nielsen ◽  
Marek Polanski ◽  
Bjarne R. S. Hansen ◽  
Søren Tolborg ◽  
Dorthe B. Ravnsbæk ◽  
...  
Keyword(s):  
Hydrogen Storage ◽  
Nickel Nanoparticles ◽  
Carbon Materials ◽  
Hydrogen Release ◽  
Commercial Application ◽  
Carbon Aerogels ◽  
Enthalpy Of Reaction ◽  
Scanning Calorimetry ◽  
Decomposition Pathway ◽  
Kinetics Of

ABSTRACTLiBH4 and MgH2 both have high gravimetric and volumetric hydrogen storage densities. Unfortunately, their commercial application is prevented by high thermal stability and unfavorable thermodynamic properties. Combining the two hydrides leads to a new decomposition pathway with suitable enthalpy of reaction. However, the kinetics for hydrogen release remains an obstacle but can be improved by nanoconfinement in nano porous carbon materials. Here we report on nanoconfinement of 2LiBH4-MgH2 in Ni functionalized carbon aerogels. 11B MAS NMR reveals that the nanoconfined hydrides react reversibly with hydrogen whereas simultaneous differential scanning calorimetry and mass spectroscopy clearly show that nanoconfinement facilitates lower hydrogen release temperatures than ball milling. Furthermore, Ni functionalization of the nanoporous aerogel leads to even lower hydrogen release temperatures from nanoconfined 2LiBH4-MgH2.

scholarly journals Hydrogen Storage in Propane-Hydrate: Theoretical and Experimental Study

2020 ◽  
Vol 10 (24) ◽  
pp. 8962
Author(s):  
Mohammad Reza Ghaani ◽  
Satoshi Takeya ◽  
Niall J. English
Keyword(s):  
Hydrogen Storage ◽  
Storage Capacity ◽  
Fixed Bed ◽  
Hydrogen Uptake ◽  
Hydrogen Release ◽  
Fixed Bed Reactor ◽  
Gas Dispersion ◽  
Fixed Bed Reactors ◽  
Non Equilibrium Molecular Dynamics ◽  
Kinetics Of

There have been studies on gas-phase promoter facilitation of H2-containing clathrates. In the present study, non-equilibrium molecular dynamics (NEMD) simulations were conducted to analyse hydrogen release and uptake from/into propane planar clathrate surfaces at 180–273 K. The kinetics of the formation of propane hydrate as the host for hydrogen as well as hydrogen uptake into this framework was investigated experimentally using a fixed-bed reactor. The experimental hydrogen storage capacity propane hydrate was found to be around 1.04 wt% in compare with the theoretical expected 1.13 wt% storage capacity of propane hydrate. As a result, we advocate some limitation of gas-dispersion (fixed-bed) reactors such as the possibility of having un-reacted water as well as limited diffusion of hydrogen in the bulk hydrate.

scholarly journals Solid-State Hydrogen Storage: Materials, Systems and the Relevance of a Gender Perspective

2021 ◽  
Author(s):  
Erika Michela Dematteis ◽  
Jussara Barale ◽  
Marta Corno ◽  
Alessandro Sciullo ◽  
Marcello Baricco ◽  
...  
Keyword(s):  
Solid State ◽  
Hydrogen Storage ◽  
Operating Conditions ◽  
Hydrogen Sorption ◽  
Enthalpy Of Reaction ◽  
Gender Perspective ◽  
The Social ◽  
The Impact ◽  
Kinetics Of

This paper aims at addressing the exploitation of solid-state carriers for hydrogen storage, with attention paid both to the technical aspects, through a wide review of the available integrated systems, and to the social aspects, through a preliminary overview of the connected impacts from a gender perspective. As for the technical perspective, carriers to be used for solid-state hydrogen storage for various applications can be classified into two classes: metal and complex hydrides. Related crystal structures and corresponding hydrogen sorption properties are reviewed and discussed. Fundamentals of thermodynamics of hydrogen sorption evidences the key role of the enthalpy of reaction, which determines the operating conditions (i.e. temperatures and pressures). In addition, it rules the heat to be removed from the tank during hydrogen absorption and to be delivered to the tank during hydrogen desorption. Suitable values for the enthalpy of hydrogen sorption reaction for operating conditions close to ambient (i.e. room temperature and 1-10 bar of hydrogen) are close to 30 kJ·molH2 1. The kinetics of hydrogen sorption reaction is strongly related to the microstructure and to the morphology (i.e. loose powder or pellets) of the carriers. Usually, kinetics of hydrogen sorption reaction is rather fast, and the thermal management of the tank is the rate determining step of the processes. As for the social perspective, various scenarios for the applications in different socio-economic contexts of solid-state hydrogen storage technologies are described. As it occurs with the exploitation of other renewables innovative technologies, a wide consideration of the social factors connected to these processes is needed to assess the extent to which a specific innovation might produce positive or negative impacts in the recipient socio-economic system and to explore the potential role of the social components and dynamics in fostering the diffusion of the innovation itself. Attention has been addressed to the gender perspective, in view of the enhancement of hydrogen-related energy storage systems, intended both in terms of the role of women in triggering the exploitation of hydrogen-based storage as well as to the impact of this innovation in their current conditions, at work and in daily life.

Effect of Pore Size on Dehydrogenation Temperature of Carbon Cryogel-Ammoniaborane Nanocomposites

2008 ◽  
Vol 1098 ◽  
Author(s):  
Saghar Sepehri ◽  
Betzaida Batalla Garcia ◽  
Guozhong Cao
Keyword(s):  
Differential Scanning Calorimetry ◽  
Hydrogen Storage ◽  
Pore Size ◽  
Porous Carbon ◽  
Ammonia Borane ◽  
Scanning Calorimetry ◽  
Resorcinol Formaldehyde ◽  
Dehydrogenation Kinetics ◽  
Carbon Cryogel ◽  
Kinetics Of

AbstractThis study reports the effects of pore size of porous carbon scaffold on the dehydrogenation of ammoniaborane in the coherent carbon- ammoniaborane nanocomposites. Porous carbon scaffold is obtained from resorcinol formaldehyde derived carbon cryogels. The nanocomposites are made by simple soaking porous carbon scaffold in ammonia borane solution. Nitrogen sorption analysis and differential scanning calorimetry are used to investigate the structure and dehydrogenation of the nanocomposites. The results reveal that dehydrogenation temperature decreases in nanocomposites as compared to neat ammonia borane, and is lower in nanocomoposites with smaller pore sizes. These findings can be used to tune the dehydrogenation temperature to meet specific hydrogen storage applications. Also, dehydrogenation kinetics of nanocomposites is enhanced as compared to neat ammonia borane.

Modified Carbon Cryogel-Ammonia Borane Nanocomposites for Hydrogen Storage

2007 ◽  
Vol 1042 ◽  
Author(s):  
Saghar Sepehri ◽  
Betzaida Batalla Garcia ◽  
Qifeng Zhang ◽  
Guozhong Cao
Keyword(s):  
Hydrogen Storage ◽  
Photoelectron Spectroscopy ◽  
Ammonia Borane ◽  
Scanning Calorimetry ◽  
Dehydrogenation Kinetics ◽  
Carbon Cryogel ◽  
Nitrogen Doped Carbon ◽  
Kinetics Of ◽  
Catalytic Effects

AbstractThis paper reports the synthesis and characterization of coherent Boron/Nitrogen –doped –carbon cryogels- ammonia borane nanocomposites for hydrogen storage. Resorcinol formaldehyde derived doped carbon cryogels (CC) were obtained via chemical modification.CC- ammonia-borane nanocomposites were made by incorporation of ammonia borane (AB), in CCs. Nitrogen sorption analysis, scanning electron microscopy, and X-ray photoelectron spectroscopy, are used to investigate the structure and morphology of the modified CCs. Differential scanning calorimetry is used to study the dehydrogenation of coherent doped-CC-AB nanocomposites. Modified CCs show higher mesoporosity, and more homogeneous porous structure compared to undoped CCs. Also, dehydrogenation kinetics of nanocomposites is enhanced as compared to neat AB. Possible nanoscale and catalytic effects of nanocomposites in improved dehydrogenation kinetics are discussed.

scholarly journals The Effect of Graphite and Fe2O3 Addition on Hydrolysis Kinetics of Mg-Based Hydrogen Storage Materials

2021 ◽  
Vol 2021 ◽  
pp. 1-8
Author(s):  
Kun Yang ◽  
Hongyun Qin ◽  
Junnan Lv ◽  
Rujun Yu ◽  
Xia Chen ◽  
...  
Keyword(s):  
Hydrogen Storage ◽  
Conversion Rate ◽  
Composite Powder ◽  
Physical Structure ◽  
Hydrogen Release ◽  
Hydrolysis Kinetics ◽  
Hydrogen Storage Materials ◽  
Storage Materials ◽  
Kinetics Of ◽  
Hydrolysis Of

In this paper, graphite and Fe2O3 are introduced into MgH2 powder by the method of hydrogenation after magnetic grinding. Hydrogen storage materials which composite of MgH2–5 wt.% C and MgH2–5 wt.% C–5 wt.% Fe2O3 are successfully prepared. The physical structure of these materials was analyzed and characterized by XRD, SEM, etc. Furthermore, the influence of graphite and Fe2O3 on the hydrolysis of MgH2 was systematically investigated. The results show that MgH2–C–Fe2O3 composite powder has the fastest hydrogen release rate in municipal drinking water and the highest conversion rate. Graphite and Fe2O3 can effectively reduce the activation energy of the hydrolysis reaction of MgH2 and improve the hydrolysis kinetics of MgH2. The synergistic effect of the coaddition of graphite and Fe2O3 can significantly increase the hydrolysis conversion rate of MgH2 and improve the hydrolysis kinetics.

scholarly journals Solid-State Hydrogen Storage Systems and the Relevance of a Gender Perspective

Energies ◽  
2021 ◽  
Vol 14 (19) ◽  
pp. 6158
Author(s):  
Erika Michela Dematteis ◽  
Jussara Barale ◽  
Marta Corno ◽  
Alessandro Sciullo ◽  
Marcello Baricco ◽  
...  
Keyword(s):  
Solid State ◽  
Hydrogen Storage ◽  
Storage Systems ◽  
Operating Conditions ◽  
Hydrogen Sorption ◽  
Enthalpy Of Reaction ◽  
Gender Perspective ◽  
The Social ◽  
Kinetics Of

This paper aims at addressing the exploitation of solid-state carriers for hydrogen storage, with attention paid both to the technical aspects, through a wide review of the available integrated systems, and to the social aspects, through a preliminary overview of the connected impacts from a gender perspective. As for the technical perspective, carriers to be used for solid-state hydrogen storage for various applications can be classified into two classes: metal and complex hydrides. Related crystal structures and corresponding hydrogen sorption properties are reviewed and discussed. Fundamentals of thermodynamics of hydrogen sorption evidence the key role of the enthalpy of reaction, which determines the operating conditions (i.e., temperatures and pressures). In addition, it rules the heat to be removed from the tank during hydrogen absorption and to be delivered to the tank during hydrogen desorption. Suitable values for the enthalpy of hydrogen sorption reaction for operating conditions close to ambient (i.e., room temperature and 1–10 bar of hydrogen) are close to 30 kJ·molH2−1. The kinetics of the hydrogen sorption reaction is strongly related to the microstructure and to the morphology (i.e., loose powder or pellets) of the carriers. Usually, the kinetics of the hydrogen sorption reaction is rather fast, and the thermal management of the tank is the rate-determining step of the processes. As for the social perspective, the paper arguments that, as it occurs with the exploitation of other renewable innovative technologies, a wide consideration of the social factors connected to these processes is needed to reach a twofold objective: To assess the extent to which a specific innovation might produce positive or negative impacts in the recipient socioeconomic system and, from a sociotechnical perspective, to explore the potential role of the social components and dynamics in fostering the diffusion of the innovation itself. Within the social domain, attention has been paid to address the underexplored relationship between the gender perspective and the enhancement of hydrogen-related energy storage systems. This relationship is taken into account both in terms of the role of women in triggering the exploitation of hydrogen-based storage playing as experimenter and promoter, and in terms of the intertwined impact of this innovation in their current conditions, at work, and in daily life.

Improved Hydrogen Desorption Kinetics of MgH2 Nanoparticles by Using TiC Nanocatalyst

2012 ◽  
Vol 510-511 ◽  
pp. 371-377 ◽  
Author(s):  
N.A. Niaz ◽  
S.T. Hussain ◽  
S. Nasir ◽  
I. Ahmad
Keyword(s):  
Hydrogen Storage ◽  
Surface Condition ◽  
Hydrogen Desorption ◽  
High Energy ◽  
Desorption Kinetics ◽  
X Rays ◽  
Scanning Calorimetry ◽  
Practical Applications ◽  
Slow Kinetics ◽  
Kinetics Of

Magnesium hydride (MgH2) is considered to be a promising hydrogen storage material because of its high gravimetric and volumetric storage capacities. However, its slow kinetics and high desorption temperature (> 300 °C) limit the practical applications. We have selected TiC nanoparticles to modify the hydrogen storage properties of MgH2. First, Mg nanoparticles were synthesized by thermal desorption of bipyridyl complex of Mg and then MgH2nanoparticles were obtained by hydriding the Mg nanoparticles. Composite mixtures (MgH2+ TiC) were prepared using high-energy ball milling. Structural analysis, morphology and particle size were investigated by X-rays diffractometer (XRD) and scanning electron microscopy (SEM) respectively. Hydrogen desorption properties of MgH2was investigated with various amount of TiC nanocatalyst using differential scanning calorimetry (DSC) and seivertz type apparatus (PCT). Desorption kinetics were also studied by pressure composition isotherm (PCI). Results show that the product reveals good reversible hydrogen absorption-desorption cycles even at >150 °C. The hydrogen desorption kinetics of catalyzed and noncatalyzed MgH2could be understood by a modified first-order reaction model, in which the surface condition was taken into account.

scholarly journals Thermal Stability and Decomposition Pathways in Volatile Molybdenum(VI) Bis-Imides

2021 ◽  
Author(s):  
Michael Land ◽  
Goran Bacic ◽  
Katherine Robertson ◽  
Sean Barry
Keyword(s):  
Thermal Stability ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
Atomic Layer ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Layer Deposition ◽  
Reaction Barriers ◽  
Decomposition Pathway ◽  
Kinetics Of

The vapor deposition of many molybdenum-containing films relies on the delivery of volatile compounds with the general bis(tert-butylimido)molybdenum(VI) framework, both in atomic layer deposition and chemical vapor deposition. We have prepared a series of (tBuN)2MoCl2 adducts using neutral N,N’-chelates and investigated their volatility, thermal stability, and decomposition pathways. Volatility has been determined by thermogravimetric analysis, with the 1,4-di-tert-butyl-1,3-diazabutadiene adduct (5) found to be the most volatile (1 Torr of vapor pressure at 135 ºC). Thermal stability was measured primarily using differential scanning calorimetry, and the 1,10-phenanthroline adduct (4) was found to be the most stable, with an onset of decomposition of 303 ºC. We have also investigated molybdenum compounds with other alkyl-substituted imido groups: these compounds all follow a similar decomposition pathway, γ-H activation, with varying reaction barriers. The tert-pentyl, 1-adamantyl, and a cyclic imido (from 2,5-dimethylhexane-2,5-diamine) were systematically studied to probe the kinetics of this pathway. All of these compounds have been fully characterized, including via single-crystal X-ray diffraction, and a total of 19 unique structures are reported.

Study of nickel-molybdenum catalysts for methanation of carbon monoxide

1980 ◽  
Vol 45 (3) ◽  
pp. 783-790 ◽  
Author(s):  
Petr Taras ◽  
Milan Pospíšil
Keyword(s):  
Carbon Monoxide ◽  
Catalytic Activity ◽  
Mixed Oxides ◽  
Minor Component ◽  
Fast Neutrons ◽  
Scanning Calorimetry ◽  
Low Concentrations ◽  
Γ Rays ◽  
Molybdenum Catalysts ◽  
Kinetics Of

Catalytic activity of nickel-molybdenum catalysts for methanation of carbon monoxide and hydrogen was studied by means of differential scanning calorimetry. The activity of NiMoOx systems exceeds that of carrier-free nickel if x < 2, and is conditioned by the oxidation degree of molybdenum, changing in dependence on the composition in the region Mo-MoO2. The activity of the catalysts is adversely affected by irradiation by fast neutrons, dose 28.1 Gy, or by γ rays using doses in the region 0.8-52 kGy. The system is most susceptible to irradiation in the region of low concentrations of the minor component (about 1 mol.%). The dependence of changes in catalytic activity of γ-irradiated samples on the dose exhibits a maximum in the range of 2-5 kGy. The changes in catalytic activity are stimulated by the change of reactivity of the starting mixed oxides, leading to different kinetics of their reduction and modification of their adsorption properties. The irradiation of the catalysts results in lowered concentration of the active centres for the methanation reaction.

scholarly journals Thermal analysis: basic concept of differential scanning calorimetry and thermogravimetry for beginners

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Nurul Fatahah Asyqin Zainal ◽  
Jean Marc Saiter ◽  
Suhaila Idayu Abdul Halim ◽  
Romain Lucas ◽  
Chin Han Chan
Keyword(s):  
Thermal Analysis ◽  
Differential Scanning Calorimetry ◽  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Commercial Application ◽  
Scanning Calorimetry ◽  
Teaching Activities ◽  
Sample Decomposition ◽  
Calibration Baseline

AbstractWe present an overview for the basic fundamental of thermal analysis, which is applicable for educational purposes, especially for lecturers at the universities, who may refer to the articles as the references to “teach” or to “lecture” to final year project students or young researchers who are working on their postgraduate projects. Description of basic instrumentation [i.e. differential scanning calorimetry (DSC) and thermogravimetry (TGA)] covers from what we should know about the instrument, calibration, baseline and samples’ signal. We also provide the step-by-step guides for the estimation of the glass transition temperature after DSC as well as examples and exercises are included, which are applicable for teaching activities. Glass transition temperature is an important property for commercial application of a polymeric material, e.g. packaging, automotive, etc. TGA is also highlighted where the analysis gives important thermal degradation information of a material to avoid sample decomposition during the DSC measurement. The step-by-step guides of the estimation of the activation energy after TGA based on Hoffman’s Arrhenius-like relationship are also provided.

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