The development of nanoporous hydrogen storages презентация

cars - hydrogen
Why is hydrogen needed?
A modern commercially available car with a range of 400 km burns about 24 kg of petrol in a combustion engine or 8 kg of hydrogen.

For the electric car where hydrogen reacts with oxygen in a fuel cell by means the reaction
Н2 → 2Н+ + 2e-
O2 + 4H+ + 4e- → 2H2O,
is needed only 4 kg of hydrogen

What is the problem?
At the temperature 20oC and pressure 1 bar
4 kg of hydrogen occupied a volume of 45 m3.


What`s the way to squeeze 4 kg of hydrogen in a car?

2008 year
97% of transportation fuel comes from
crude oil
25% of global greenhouse emission are generated by cars
The number of cars - 750 millions
2050 year
The number of cars - 2.2 billions
Crude oil comes to an end

2008 year
Distribution of total world primary energy supply

700 atmospheres.
Disadvantages – spontaneous leak of hydrogen and high risk of depressurization.
Storage in liquid state– (-252°С).
Disadvantages – thigh cost of equipment for hydrogen storage and cooling, evaporation and high risk of depressurization.

Hydrogen storage in solid state.
Requirements.
Gravimetric capacitance- > 6 weight % H2, Hydrogen pressure at its saturation - < 3 МPа,
Hydrogenation time - < 5 minutes, Temperature of hydrogen desorption - < 85°С

Porous
(physical adsorption)

1. Carbon nanostructures
Nanotubes (single-layer, multilayer),
nanofibers, fullerene, graphene,
activated carbon.

2. Metal - organic structures
MOF-5,177 (Zn4O-[O2C-C6H4-CO2]2),
MIL-53,101(Cr,Al,O [O2C-C6H4-CO2]2),
IMOF-1,3,12 (Zn4O-CxHy(CO2)2)

Compact
(chemical adsorption)

Mg - based hydrides
MgH2 – (Ti, V, Ni, Cu, Fe, Mn),
MgH2 – (V2O5, Nb2O5, Fe2O3, Al2O3, TiO2)
Complex hydrides
NaAlH6, LiAlH4, KAlH4
3. LiN - based hydrides
LiNH2, Li2NH, Li2MgN2H2, Li3BN2H8
4. Intermetallic compounds
LaNi5, FeTi, TiVCr, TiZrNi, TiCrMn

So far none of the solid-state hydrogen accumulators satisfy
the necessary requirements.

of film deposition.
The thickness – 10 nm

The thickness – 1 µm

Porosity – 32%

Porosity – 9%

Our idea To create such a material, which would be able to accumulate hydrogen both in its atomic and molecular states. Complex hydrides (V, Ti, Mg)Ny

Scanning and transmission microscopy.

Initial state

H2, 0,3 MPa, 1 hour, 20oC

Annealing 250oC

– 9%

(V, 0,1Ti)Nx

Gravimetric capacity of nanoporous structures is determined not only by porosity, but also
by average pore size.

Relatively large pores (>8-10 nm) do not retain
hydrogen at room temperature and
atmospheric pressure.
The main part of hydrogen is accumulated
within nano grains.

pores filling

Hydrogen dissociation

Vacancy traps filling

at 50°С.
The maximum speed of hydrogen release is observed at 250°С.

2. The application of protective nickel layer of 10 nm
thick lowers the temperature of maximum
hydrogen release by 50°С and increases its total
absorbed amount by 10%.

TiN, Mg3N2) can be used as a solid-state hydrogen storages successfully.

Ion-beam assisted technology is an effective method of such thin film nanocrystalline materials preparation.

High degree of non equilibrium of current method in aggregate with varying its basic parameters component make possible to produce nanocrystalline structures (5-10 nm), in which the intergranular joints can contain nanopores (3-5 nm). Such structures are capable to accumulate more than 7 wt. % of hydrogen.

The important role of open nanoporosity (pore ensemble joined with grain boundaries) is in branched network creation in which hydrogen penetrates into storage volume at a low pressure (< 0,5 МPа) and short time interval (~2-5 min).