scholarly journals Enhancing Hydrogen Storage Kinetics and Cycling Properties of NaMgH3 by 2D Transition Metal Carbide MXene Ti3C2

Processes ◽  
2021 ◽  
Vol 9 (10) ◽  
pp. 1690
Author(s):  
Zhouming Hang ◽  
Zhencan Hu ◽  
Xuezhang Xiao ◽  
Ruicheng Jiang ◽  
Meng Zhang
Keyword(s):  
Hydrogen Storage ◽  
Lamellar Structure ◽  
High Efficiency ◽  
Thermal Storage ◽  
Hydrogen Desorption ◽  
Transition Metal Carbide ◽  
Kinetic Properties ◽  
Storage Density ◽  
De Re ◽  
Storage Materials

Metal hydrides have recently been proposed for not only hydrogen storage materials but also high-efficiency thermal storage materials. NaMgH3 contains a considerable theoretical thermal storage density of 2881 kJ/kg. However, its sluggish de/re-hydrogenation reaction kinetics and poor cycling stability exhibit unavailable energy efficiency. Doping with active catalyst into NaMgH3 is deemed to be a potential strategy to mitigate these disadvantages. In this work, the enhancement of de/re-hydrogenation kinetics and cycling properties of NaMgH3 is investigated by doping with lamellar-structure 2D carbon-based MXene, Ti3C2. Results shows that introducing 7 wt.% Ti3C2 is proved to perform excellent catalytic efficiency for NaMgH3, dramatically reducing the two-step hydrogen desorption peak temperatures (324.8 and 345.3 °C) and enhancing the de/re-hydrogenation kinetic properties with the hydrogen desorption capacity of 4.8 wt.% H2 within 15 min at 365 °C and absorption capacity of 3.5 wt.% H2 within 6 s. Further microstructure analyses reveal that the unique lamellar-structure of Ti3C2 can separate the agglomerated NaMgH3 particles homogeneously and decrease the energy barriers of two-step reaction of NaMgH3 (114.08 and 139.40 kJ/mol). Especially, lamellar-structure Ti3C2 can improve the reversibility of hydrogen storage of NaMgH3, rendering 4.6 wt.% H2 capacity remained after five cycles. The thermal storage density of the composite is determined to be 2562 kJ/kg through DSC profiles, which is suitable for thermal energy storage application.

Crystallitic Structure and Thermodynamics of Magnesium-Based Hydrogen Storage Materials from Reactive Milling under Hydrogen Atmosphere

2013 ◽  
Vol 724-725 ◽  
pp. 1021-1024
Author(s):  
Shi Xue Zhou ◽  
Qian Qian Zhang ◽  
Nai Fei Wang ◽  
Zong Ying Han ◽  
Wei Xian Ran ◽  
...  
Keyword(s):  
Hydrogen Storage ◽  
Xrd Analysis ◽  
Hydrogen Desorption ◽  
Hydrogen Atmosphere ◽  
Hydrogen Storage Materials ◽  
Storage Materials ◽  
Reactive Milling ◽  
Anthracite Coal ◽  
Enthalpy And Entropy Changes ◽  
Hoff Equation

Magnesium-based hydrogen storage materials were prepared by reactive milling of magnesium under hydrogen atmosphere with crystallitic carbon, prepared from anthracite coal, as milling aid. The XRD analysis shows that in the presence of 30 wt.% of crystallitic carbon, the Mg easily hydrided into β-MgH2of crystal grain size 29.7 nm and a small amount of γ-MgH2after 3 h of milling under 1 MPa H2. The enthalpy and entropy changes of the hydrogen desorption reaction are 42.7 kJ/mol and 80.7 J/mol K, respectively, calculated by the vant Hoff equation from thep-C-Tdata in 300-380°C.

scholarly journals Catalytic Tuning of Sorption Kinetics of Lightweight Hydrides: A Review of the Materials and Mechanism

Catalysts ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 651 ◽  
Author(s):  
Ankur Jain ◽  
Shivani Agarwal ◽  
Takayuki Ichikawa
Keyword(s):  
Hydrogen Storage ◽  
Activation Barrier ◽  
Sorption Kinetics ◽  
Kinetic Properties ◽  
Intermediate Step ◽  
Hydrogen Storage Materials ◽  
Storage Materials ◽  
Complex Hydrides ◽  
The Us ◽  
Kinetics Of

Hydrogen storage materials have been a subject of intensive research during the last 4 decades. Several developments have been achieved in regard of finding suitable materials as per the US-DOE targets. While the lightweight metal hydrides and complex hydrides meet the targeted hydrogen capacity, these possess difficulties of hard thermodynamics and sluggish kinetics of hydrogen sorption. A number of methods have been explored to tune the thermodynamic and kinetic properties of these materials. The thermodynamic constraints could be resolved using an intermediate step of alloying or by making reactive composites with other hydrogen storage materials, whereas the sluggish kinetics could be improved using several approaches such as downsizing and the use of catalysts. The catalyst addition reduces the activation barrier and enhances the sorption rate of hydrogen absorption/desorption. In this review, the catalytic modifications of lightweight hydrogen storage materials are reported and the mechanism towards the improvement is discussed.

scholarly journals The Improvement in Hydrogen Storage Performance of MgH2 Enabled by Multilayer Ti3C2

Micromachines ◽  
2021 ◽  
Vol 12 (10) ◽  
pp. 1190
Author(s):  
Zhaojie Wu ◽  
Jianhua Fang ◽  
Na Liu ◽  
Jiang Wu ◽  
Linglan Kong
Keyword(s):  
Hydrogen Storage ◽  
Hydrogen Absorption ◽  
Synergistic Effects ◽  
Hot Spot ◽  
Storage System ◽  
Single Layer ◽  
Hydrogen Desorption ◽  
Transition Metal Carbide ◽  
Hydrogen Storage System ◽  
Hydrogen Molecules

MgH2 has become a hot spot in the research of hydrogen storage materials, due to its high theoretical hydrogen storage capacity. However, the poor kinetics and thermodynamic properties of hydrogen absorption and desorption seriously hinder the development of this material. Ti-based materials can lead to good effects in terms of reducing the temperature of MgH2 in hydrogen absorption and desorption. MXene is a novel two-dimensional transition metal carbide or carbonitride similar in structure to graphene. Ti3C2 is one of the earliest and most widely used MXenes. Single-layer Ti3C2 can only exist in solution; in comparison, multilayer Ti3C2 (ML-Ti3C2) also exists as a solid powder. Thus, ML-Ti3C2 can be easily composited with MgH2. The MgH2+ML-Ti3C2 composite hydrogen storage system was successfully synthesized by ball milling. The experimental results show that the initial desorption temperature of MgH2-6 wt.% ML-Ti3C2 is reduced to 142 °C with a capacity of 6.56 wt.%. The Ea of hydrogen desorption in the MgH2-6 wt.% ML-Ti3C2 hydrogen storage system is approximately 99 kJ/mol, which is 35.3% lower than that of pristine MgH2. The enhancement of kinetics in hydrogen absorption and desorption by ML-Ti3C2 can be attributed to two synergistic effects: one is that Ti facilitates the easier dissociation or recombination of hydrogen molecules, while the other is that electron transfer generated by multivalent Ti promotes the easier conversion of hydrogen. These findings help to guide the hydrogen storage properties of metal hydrides doped with MXene.

Modelling of Mg/Ti and Mg/Nb Thin Films for Hydrogen Storage

2011 ◽  
Vol 170 ◽  
pp. 298-301 ◽  
Author(s):  
Konstantin Klyukin ◽  
Marina G. Shelyapina ◽  
Daniel Fruchart
Keyword(s):  
Thin Films ◽  
Hydrogen Storage ◽  
Ab Initio ◽  
Ab Initio Calculation ◽  
Hydrogen Sorption ◽  
Kinetic Properties ◽  
Sorption Kinetic ◽  
Hydrogen Storage Materials ◽  
Storage Materials ◽  
The Stability

Mg/TM thin films are objects of interest as hydrogen storage materials due to their expected interesting thermodynamic and hydrogen sorption kinetic properties. Here we report on the results of ab initio calculation on the stability of Mgn/Ti and Mgn/Nbm thin films.

Interrelation between Hydrogen Desorption Kinetics and Structure of (Mg2Ni)Hx and Hydrogenated Eutectic(Mg/Mg2Ni)Hy

2009 ◽  
Vol 289-292 ◽  
pp. 167-174
Author(s):  
Jiri Cermak ◽  
Lubomir Kral
Keyword(s):  
Diffusion Coefficient ◽  
Binary System ◽  
Low Temperature ◽  
Hydrogen Storage ◽  
Eutectic Mixture ◽  
Hydrogen Desorption ◽  
Desorption Kinetics ◽  
Hydrogen Storage Materials ◽  
Storage Materials ◽  
Intermetallic Diffusion

Mg-rich alloys of the binary system Mg-Ni are prospective hydrogen-storage materials. In the present study, desorption characteristics of hydrided Mg2Ni intermetalic and hydrided Mg/Mg2Ni eutectic mixture were investigated. Structure of experimental materials during the hydrogenation was observed by SEM. Three modifications of (Mg2Ni)Hx (x ~ 4) were prepared differing in the ratio of two low-temperature phases f = LT2/LT1: with (i) f >1, (ii) f ~ 1 and with (iii) f <1. Evolution of the ratio f during hydrogen desorption was checked by XRD. It was found that the micro-twinned phase LT2 is not desirable in hydrogen-storage materials containing Mg2Ni intermetallic. Diffusion coefficient of hydrogen in LT2 is about 20 times lower than in LT1.

Blending materials composed of boron, nitrogen and carbon to transform approaches to liquid hydrogen stores

2016 ◽  
Vol 45 (14) ◽  
pp. 6196-6203 ◽  
Author(s):  
Sean M. Whittemore ◽  
Mark Bowden ◽  
Abhijeet Karkamkar ◽  
Kshitij Parab ◽  
Doinita Neiner ◽  
...  
Keyword(s):  
Liquid Phase ◽  
Hydrogen Storage ◽  
Liquid Hydrogen ◽  
Hydrogen Release ◽  
Thermally Stable ◽  
Hydrogen Storage Materials ◽  
Fuel Blend ◽  
Storage Density ◽  
Storage Materials ◽  
Boron Nitrogen

Mixtures of hydrogen storage materials are examined to find a ‘fuel blend’ that remains a liquid phase throughout hydrogen release, maximizes hydrogen storage density, minimizes impurities and is thermally stable.

scholarly journals Hydrogen Desorption Properties of MgH2 + 10 wt% SiO2 + 5 wt% Ni Prepared by Planetary Ball Milling

2021 ◽  
Vol 16 (2) ◽  
pp. 280-285
Author(s):  
Malahayati Malahayati ◽  
Evi Yufita ◽  
Ismail Ismail ◽  
Mursal Mursal ◽  
Rinaldi Idroes ◽  
...  
Keyword(s):  
Hydrogen Storage ◽  
Ball Milling ◽  
Milling Time ◽  
Thermodynamic Characteristics ◽  
Hydrogen Desorption ◽  
High Energy ◽  
Kinetic Properties ◽  
Hydrogen Storage Material ◽  
Storage Material ◽  
Solid Form

MgH2 is a very hopeful material for application as hydrogen storage material in the solid form. This is due to its reversibility and its ability to store large amounts of hydrogen, which is 7.6 wt%. However, this material still has weaknesses, namely high operating temperature and slow kinetic reactions. Various attempts have been made to overcome this weakness, including downsizing and adding catalyst. In this study, double catalyst was used, namely natural silica extracted from rice husk ash and nickel nano powder, with a composition of MgH2 + 10 wt% SiO2 + 5 wt% Ni. The purpose of this research was to study the effect of downsizing and using these catalysts to the thermodynamic and kinetic properties of the hydrogen storage material MgH2. Samples were prepared by using High Energy Ball Milling (HEBM), with variations in milling time of 1, 5, 10, and 15 hours. The X-ray Diffraction (XRD) pattern showed the presence of an impurity phase in the samples milled for 10 and 15 hours. It also showed a reduction in grain size with increasing milling time. However, agglomeration has occurred in the samples milled for 15 hours. From the Scanning Electron Microscope (SEM) results can be seen that the sample with longer milling time, were homogeneously distribute. Thermal investigation showed that the lowest desorption temperature was achieved in samples with milling time of 5 and 10 hours, namely 287 °C and 288 °C. This study shows that natural silica catalyst plays a role in improving the thermodynamic characteristics of MgH2, while Ni plays a role in improving the kinetic characteristics of MgH2. Copyright © 2021 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0). 

Cycling hydrogen desorption properties and microstructures of MgH2–AlH3–NbF5 hydrogen storage materials

Rare Metals ◽  
2020 ◽  
Author(s):  
Xiao-Sheng Liu ◽  
Hai-Zhen Liu ◽  
Ning Qiu ◽  
Yan-Bing Zhang ◽  
Guang-Yao Zhao ◽  
...  
Keyword(s):  
Hydrogen Storage ◽  
Hydrogen Desorption ◽  
Hydrogen Storage Materials ◽  
Storage Materials
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