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NSTF Energy Workshop
Bloemfontein
Dr. E.H.G. Langner
Department of Chemistry
NANOPOROUS MATERIALS IN ENERGY APPLICATIONS
NANOPOROUS MATERIALS
MOF 5 :
Zn4O(C8H4O4)3
Organic
Ligand
Metal node
Drugs transport
and release
Catalysis
Gas storage
and
purification
Metal Organic Frameworks
1.85 nm pore width
ENERGY APPLICATIONS
Mn
Mn Pt
Pt Pt
H2O O2 H+
e-
H2+
e-
Tuneable pore sizes
Molecular anode Molecular cathode
Conjugated linker connecting metals
Functionalized organic ligands
with terminal COOH groups
Mn
Mn Pt
Pt Pt
H2O O2 H+
e-
H2+
e-
Tuneable pore sizes
Molecular anode Molecular cathode
Conjugated linker connecting metals
Functionalized organic ligands
with terminal COOH groups
Catalysis: Hydrogen production
ENERGY APPLICATIONS
Fuel Cells: PEM
"The product is ready for the market technically...the time for electric vehicles with fuel cells has come.” -Dieter Zetsche, Chairman, Daimler AG “...fuel cell vehicles could be commercialized by 2015, and cost competitive by 2022.” - Charles Freese, Executive Director of Fuel Cell Activities, General Motors
ENERGY APPLICATIONS
Fuel Cells: Methane Storage
EcoFuel Asia Tour 2007 – Berlin to Bangkok
32 000 km
1.3 tons less
CO2 than petrol
Tanks with CH4
at 200 bar
30 % more than
without the MOF
Basolite C300
Cu3(BTC)2
7 kg of natural gas per 100 km
ENERGY APPLICATIONS
Fuel Cells: Hydrogen Storage
CHALLENGE: Light, compact, durable,
affordable, and responsive hydrogen storage
system on-board the vehicle.
OPTIMIZATION NEEDED FOR:
storage capacity
temperature of hydrogen release
kinetics/speed of hydrogen
refueling
H2 can bind to surfaces at low temperatures
Materials with large surface areas might improve the
tank capacity enough to offset the penalty for cooling
Considerable research underway on such materials
activated carbon: 2500 m2/g; 5 mass% @ 77K
MOFs: 5000 m2/g; 5-7 mass% @ 77K
ENERGY APPLICATIONS
Carbon capture
Framework with walls (70 m2/g)
functionalised to adsorb CO2
Human lungs: ± 70 m2
Amines Zeolites MOF
Max. Capacity <5.5% 16 wt% 15 wt%
Capacity from Air -- 1.4 wt% 8 wt%
Regeneration Temp <100 °C >135 °C <120 °C
Energy input TSA High Low Low
1 kg of the framework
= 70 000 m2
= 10 football fields
81 g of CO2 at 25C from air
121 g of CO2 at 40 C from flue gas
ENERGY APPLICATIONS
Carbon capture
High capacity from high surface area
Small volume MOF material, high volume of carbon
High adsorption from low concentration
Wide range of operating conditions and gas streams
Low heat capacity and ΔT between capture and
release (less energy needed to heat and cool down
the MOF)
Energy = cost
CONCLUSIONS
MOFs are one of the ranges of nanoporous materials
being investigated
As catalysts for Biodiesel and Hydrogen production
As Polymeric Electrolyte Membranes (PEM) in fuel cells
For purification of gas (e.g. H2 or CH4) for fuel cells
For Methane and Hydrogen storage for fuel cells
For CO2 capture from the atmosphere and flue gas