hydrogen storage materials and their development .pptx

hydrogen storage materials and their development

1. HYDROGEN STORAGE MATERIALS & THEIR DEVELOPMENT 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 S tore hydrogen gas at low temperatures and high pressures, typically below its boiling point of -252.87°C. 01 Compression C ompressing gaseous hydrogen to high pressure 350-700 bar. 02 Liquification C ooling gaseous hydrogen to extremely low temperatures, to condense it into a liquid state 03 Physical Methods to Store Hydrogen 5 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 S tore hydrogen through a chemical process where hydrogen atoms are absorbed into the crystal lattice of the metal. Mg+H 2 ↔ MgH 2 +∆H Chemical hydrides LOHC are organic molecules that can be reversibly hydrogenated and dehydrogenated to release H 2 Elemental Hydrides Intermetallic Hydrides Complex Hydrides LaNi 5 H 6 = 1.5wt% TiFeH 2 = 1.85wt% MgH 2 = 7.6 wt% AlH 3 = 10.1wt% LiBH 4 & Mg H 2 =18.5wt % hydrogen storage capacity of LOHC varies between 4.5 and 12 wt% 6

7. ( a ) H 2  is physically adsorbed on the surface of metals by van der Waals forces (b) H 2  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+H 2 ↔ MgH 2 +∆H G ravimetric hydrogen content = 7.6 wt.% V olumetric hydrogen content = 110 kgm − 3 Thermodynamically stable, due to the strong ionic bond between magnesium and hydrogen E nthalpy = 74.7 kJ mol −1 E ntropy = 130 JK −1 mol −1 Mg H 9

10. 10 Mechanism of Magnesium Hydride Formation Physisorption Chemisorption and dissociation of H 2 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 MgH 2 01 02 03 04 Strategies to i mprove Hydrog e n Storage in MgH 2 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 O 2 & H 2 O hydrogen storage Increases to 6wt% Increases the surface exposure of MgH 2 Provide Short hydrogen diffusion Path Accelerate the de-/hydrogenation kinetics of MgH 2. 12 Nano structuring of MgH 2 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 MgH 2 MgH 2 NPs confined inside the pores of Carbon aerogel The CA scaffolds have an average pore size of ∼13 nm and since confined MgH 2 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 R estricts 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 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 H ydrogen capacity low atomic weight low metallic cost Non Toxic Severe Thermal M anagement 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 MgH 2 /Mg NPs Searching for a more promising MgH 2 -hybrid system 01 02 03 04 16

17. 17 MgH 2 , as one of the most promising hydrogen storage candidate. The effective ways to alter the hydrogen storage performance of MgH 2 , 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.

18. 18 Thank You