scholarly journals Iron-catalyzed hydrogenation and dehydrogenation reactions with relevance to reversible hydrogen storage applications

2016 ◽  
Vol 2 (1) ◽  
Author(s):  
Thomas Zell ◽  
Robert Langer
Keyword(s):  
Hydrogen Storage ◽  
Small Molecules ◽  
Renewable Resources ◽  
Carbonyl Compounds ◽  
Reverse Reaction ◽  
Hydrogen Release ◽  
Practical Reasons ◽  
Highly Active ◽  
Dehydrogenation Reactions ◽  
Catalyst Systems

AbstractToday’s energy concerns require the development of suitable solutions for the storage of energy from renewable resources. Although the chemical storage of energy using molecular hydrogen as energy carrier is one of the best options, this type of energy storage requires the conversion of hydrogen to liquid organic hydrogen careers (LOHCs) for practical reasons. This goal is challenging and highly desirable at the same time. In comparison to dihydrogen, hydrogen storage in LOHCs offers easier handling and minimum dangers involved in their production, storage, and reconversion. To achieve efficient processes based on LOHCs highly active catalyst systems are required which ideally are based on cheap and abundant metals such as iron. This review summarizes recent advances in ironcatalyzed hydrogenation and dehydrogenation reactions, with relevance to reversible hydrogen storage in small molecules. It entails the dehydrogenation reactions of formic acid and methanol water mixtures, the reverse reaction, the hydrogenation of CO2, dehydrogenation of alcohols, and the hydrogenation of different carbonyl compounds as the formal reverse reaction, as well as hydrogenation and dehydrogenation reactions of N-heterocyclic compounds and hydrogen release reactions from amino boranes.

In-situ introduction of highly active TiO for enhancing hydrogen storage performance of LiBH4

2022 ◽  
pp. 134485
Author(s):  
Zhenglong Li ◽  
Mingxia Gao ◽  
Shun Wang ◽  
Xin Zhang ◽  
Panyu Gao ◽  
...  
Keyword(s):  
Hydrogen Storage ◽  
Storage Performance ◽  
Highly Active ◽  
Hydrogen Storage Performance

scholarly journals Behavior of Compacted Magnesium-Based Powders for Energy-Storage Applications

Inorganics ◽  
2020 ◽  
Vol 8 (10) ◽  
pp. 54 ◽  
Author(s):  
Daniele Mirabile Gattia ◽  
Mukesh Jangir ◽  
Indra Prabh Jain
Keyword(s):  
Energy Storage ◽  
Hydrogen Storage ◽  
Large Scale ◽  
Storage Capacity ◽  
Structural Information ◽  
Rietveld Analysis ◽  
Magnesium Hydride ◽  
Cycling Stability ◽  
Hydrogen Release ◽  
Phase Identification

Energy storage is one of the main challenges to address in the near future—in particular due to the intermittent energy produced by extensive renewable energy production plants. The use of hydrides for this type of energy storage has many positive aspects. Hydride-based systems consist of absorption and desorption reactions that are strongly exothermic and endothermic, respectively. Heat management in the design of hydrogen storage tanks is an important issue, in order to ensure high-level performance in terms of the kinetics for hydrogen release/uptake and reasonable storage capacity. When loose powder is used, material in the form of pellets should be considered in order to avoid detrimental effects including decreased cycling performance. Moreover, sustainable materials in large-scale hydrogen reactors could be recovered and reused to improve any life cycle analysis of such systems. For these reasons, magnesium hydride was used in this study, as it is particularly suitable for hydrogen storage due to its high H2 storage capacity, reversibility and the low costs. Magnesium hydride was ball-milled in presence of 5 wt % Fe as a catalyst, then compacted with an uniaxial press after the addition of expanded natural graphite (ENG). The materials underwent 45 cycles in a Sievert’s type apparatus at 310 °C and eight bar, in order to study the kinetics and cycling stability. Scanning electron microscopy was used to investigate microstructural properties and failure phenomena. Together with Rietveld analysis, X-ray diffraction was performed for phase identification and structural information. The pellets demonstrated suitable cycling stability in terms of total hydrogen storage capacity and kinetics.

Model Studies on Flavin-Dependent Carbonyl-Activation: Reduction of Carbonyl Compounds by Flavohydroquinone

1972 ◽  
Vol 27 (9) ◽  
pp. 1038-1040 ◽  
Author(s):  
G. Blankenhorn ◽  
S. Ghisla ◽  
P. Hemmerich
Keyword(s):  
Redox Reaction ◽  
Carbonyl Compounds ◽  
Reverse Reaction ◽  
Intermediate Species ◽  
Model Studies

The reduction of aldehydes by flavohydroquinone to yield the corresponding alcohols and flavoquinone is reported and discussed in view of its relevance to the mechanism of flavin-dependent dehydrogenation and carbonyl activation. With formaldehyde and flavohydroquinone formation of a covalent 5- (HO - CH2) Flred⁻ intermediate species is observed. In a reverse reaction 5-methylflavoquinonium cation undergoes an internal redox reaction to yield flavohydroquinone and formaldehyde.

Processing Analysis of the Ternary LiNH2-MgH2-LiBH4 System for Hydrogen Storage

2009 ◽  
Author(s):  
Michael U. Niemann ◽  
Sesha S. Srinivasan ◽  
Ashok Kumar ◽  
Elias K. Stefanakos ◽  
D. Yogi Goswami ◽  
...  
Keyword(s):  
Hydrogen Storage ◽  
Storage System ◽  
Hydrogen Release ◽  
Reaction Pathways ◽  
Molar Ratio ◽  
Stoichiometric Ratio ◽  
Particle Sizes ◽  
Hydrogen Capacity ◽  
Hydrogen Storage System ◽  
Milling Duration

The ternary LiNH2-MgH2-LiBH4 hydrogen storage system has been extensively studied by adopting various processing reaction pathways. The stoichiometric ratio of LiNH2:MgH2:LiBH4 is kept constant with a 2:1:1 molar ratio. All samples are prepared using solid-state mechano-chemical synthesis with a constant rotational speed, but with varying milling duration. All samples are intimate mixtures of Li-B-N-H and MgH2, with varying particle sizes. It is found that the samples with MgH2 particle sizes of approximately 10nm exhibit lower initial hydrogen release at a temperature of 150°C. The as-synthesized hydrides exhibit two main hydrogen release temperatures, one around 160°C and the other around 300°C. The main hydrogen release temperature is reduced from 310°C to 270°C, while hydrogen is first reversibly released at temperatures as low as 150°C with a total hydrogen capacity of 6 wt.%.

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.

Ammonia borane–polyethylene oxide composite materials for solid hydrogen storage

2015 ◽  
Vol 3 (7) ◽  
pp. 3683-3691 ◽  
Author(s):  
A. S. Nathanson ◽  
A. R. Ploszajski ◽  
M. Billing ◽  
J. P. Cook ◽  
D. W. K. Jenkins ◽  
...  
Keyword(s):  
Composite Materials ◽  
Hydrogen Storage ◽  
Melting Temperature ◽  
Polyethylene Oxide ◽  
Incubation Time ◽  
Ammonia Borane ◽  
Solid Hydrogen ◽  
Hydrogen Release ◽  
Crystal Phase ◽  
Oxide Composite

Co-electrospinning ammonia borane (AB) and polyethylene oxide (PEO) has created a unique crystal phase that promotes faster hydrogen release from AB below its melting temperature with no incubation time.

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