hydrogen storage materials and their development

1. 1
“ONE FOR ONE IN ONE”
HUSNA ZAHEER
MS- Inorganic Chemistry

2. What is
Hydrogen?
2

3. HYDROGEN
ECONOMY
3

4. 4
Physical Methods of
Hydrogen Storage
Chemical Methods of
Hydrogen Storage

5. Cryogenic
Compression
Store hydrogen gas
at low temperatures
and high pressures,
typically below its
boiling point of
-252.87°C.
01
Compression
Compressing gaseous
hydrogen to high
pressure 350-700 bar.
02 Liquification
Cooling gaseous
hydrogen to
extremely low
temperatures, to
condense it into a
liquid state
03
Physical Methods to Store Hydrogen
hydrogen storage capacity depends upoun tank material, volume of tank and density of
hydrogen in which form it is stored
Low
temperature

6. Chemical Methods to Store Hydrogen
Metal Hydrides
Store hydrogen through
a chemical process
where hydrogen atoms
are absorbed into the
crystal lattice of the
metal.
Mg+H2 ↔ MgH2+∆H
Chemical
hydrides
LOHC are organic
molecules that can be
reversibly hydrogenated
and dehydrogenated to
release H2
Elemental Hydrides
Intermetallic Hydrides
Complex Hydrides
LaNi5H6 = 1.5wt%
TiFeH2 = 1.85wt%
MgH2 = 7.6wt%
AlH3 = 10.1wt%
LiBH4 & MgH2 =18.5wt%
hydrogen storage capacity
of LOHC varies between
4.5 and 12wt%
6

7. (a) H2 is physically
adsorbed on the
surface of metals by
van der Waals forces
(b) H2 is chemisorbed and
dissociated to H on the surface of
metal. H penetrates the lattice
through the surface and diffuses to
the interior of the lattice
(c) The alloy
phase transforms
to the hydride
phase
Mechanism of hydrogen storage
in Metal Hydride
7

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9. How does Magnesium hydride store hydrogen?
7th most abundant element in
the crust of the Earth
with an abundance of 2.3%
Stable magnesium hydride
formation
Mg+H2 ↔ MgH2+∆H
Gravimetric hydrogen content = 7.6 wt.%
Volumetric hydrogen content =110 kgm−3
Thermodynamically
stable, due to the strong
ionic bond between
magnesium and hydrogen
Enthalpy = 74.7 kJ mol−1
Entropy = 130 JK−1mol−1
Mg H 9

10. 10
Mechanism of Magnesium Hydride Formation
Physisorption
Chemisorption and
dissociation of H2 molecule
H penetrates through the surface and
diffuse into interstitial sites
Mg hydride formed

11. Surface oxide layer formation
Low thermal conductivity
Slow hydrogen diffusion rate
in the bulk Mg
Poor hydrogen chemisorption
on Mg
Nano structuring
Catalyzing
Nanoconfinement
Existing Challenges to store
hydrogen in MgH2
01
02
03
04
Strategies to improve
Hydrogen Storage in MgH2
01
02
03
11

12. Mg Nanoparticles
Mg Nanocrystals are encapsulated by a selectively gas-
permeable polymer matrix
Protection of
reactivity of Mg
nanocrystals with
O2 & H2O
hydrogen storage
Increases to
6wt%
Increases
the surface
exposure
of MgH2
Provide
Short
hydrogen
diffusion
Path
Accelerate the
de-
/hydrogenation
kinetics of
MgH2.
12
Nano structuring
of MgH2
K.-.J. Jeon, H.R. Moon, A.M. Ruminski, B. Jiang, C. Kisielowski, R. Bardhan, J.J. Urban, Air-stable magnesium nanocomposites provide rapid and high-
capacity hydrogen storage without using heavy-metal catalysts, Nat. Mater. 10 286–290, doi:10.1038/nmat2978.

13. Nano Confinement of MgH2
MgH2 NPs confined inside the pores of
Carbon aerogel
The CA scaffolds have an average pore size
of ∼13 nm and since confined MgH2
particles are in the range of 13 nm.
Mg inside the
pores of carbon
aerogels
Effectively enhance
the gas-solid
interface
Shorten the
hydrogen diffusion
distance
Restricts particle
sintering
13
R. Gosalawit−Utke, T.K. Nielsen, K. Pranzas, I. Saldan, C. Pistidda, F. Karimi, D. Laipple, J. Skibsted, T.R. Jensen, T. Klassen, M. Dornheim, 2LiBH4–MgH2 in a
resorcinol–furfural carbon aerogel scaffold for reversible hydrogen storage, J. Phys. Chem. C 116 (2012) 1526–1534, doi:10.1021/jp2088127.
The hydrogen storage
capacity increase in the
range of 4.2–4.8 wt %

14. Hydrogen spillover process during the
hydrogen absorption process of Mg
H2 will get initially
adsorbed on the
surface of the
spillover receptor
Molecular
hydrogen gets
dissociated into
atoms
H atoms can easily
diffuse into Mg
Catalyzing
Catalyst provides an alternative
reaction path with a lower reaction
energy barrier
14
H. Shen, H. Li, Z. Yang, C. Li, Magic of hydrogen spillover: understanding and
application, Green Energy Environ. 7 (2022) 1161–1198, doi:10.1016/j.gee.2022. 01.013.

15. High
Hydrogen
capacity
low atomic
weight low
metallic
cost
Non
Toxic
Severe
Thermal
Management
Shortcomings
High
Stability
Poor
kinetics
Benefits
15

16. Potential for Future
Use of advanced theoratical
calculation
Exploring more efficient
Additives
Developing a novel approach to
stabilize the MgH2/Mg NPs
Searching for a more promising
MgH2-hybrid system
01
02
03
04
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MgH2, as one of the most promising
hydrogen storage candidate. The effective
ways to alter the hydrogen storage
performance of MgH2, i.e. nanoscaling,
nanoconfinement, and adding catalyst.
With these continuous efforts, some
applaudable achievements are obtained,
such as lowering the operation
temperature, enhancing the kinetics, and
extent the lifespan.

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Thank
You