University of Massachusetts - Amherst
ScholarWorks@UMass Amherst
Clean Energy Connections
11-22-2008
Fueling the Future through Chemical Energy of
Fuel Cells, Solar Cells, and More
DV Venkataraman
University of Massachusetts Amherst - Center for Fueling the Future
Justin Fermann
University of Massachusetts Amherst - Center for Fueling the Future
Follow this and additional works at: http://scholarworks.umass.edu/cleanenergy
Venkataraman, DV and Fermann, Justin, "Fueling the Future through Chemical Energy of Fuel Cells, Solar Cells, and More" (2008).
Clean Energy Connections. Paper 10.
http://scholarworks.umass.edu/cleanenergy/10
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Fueling the Future
through Chemical
Energy of Fuel Cells,
Solar Cells, and More
Prof. Justin Fermann
Prof. D. Venkataraman (DV)
Department of Chemistry
UMass Amherst
fermann@chem.umass.edu
dv@chem.umass.edu
2
Center for Fueling the Future
http://www.chem.umass.edu/masscrest/fuelingthefuture/
•Supported by the National Science Foundation through
Center for Chemical Innovations Program
•Research Investigators from Chemistry, Physics and
Polymer Science & Engineering
“The Center for Fueling the Future carries out research that
addresses fundamental aspects of proton transport, the
molecular-level process that underlies the functioning of a
central component of fuel cells.”
3
Hydrogen as an Energy Source
H2(g) + ½ O2 (g) Æ H2O (l) + Energy
4
Fuel Cells and Automobiles
5
Need for Better Membranes
Nafion
™Expensive
™Breaks down at high temps
™Bleeds Fuel
6
What Controls Proton Transfer?
7
What Controls Proton Transport?
8
9
Hydrogen Economy: Fundamental Questions
Efficient, Cost effective, Environmentally
Friendly , Storage and Transport
™How to break H-O-H bonds at lower temperatures?
™How to break C-H bonds at lower temperatures?
™How to reversibly convert H- to H2?
™Can H2 be physisorbed on surfaces?
Efficient Fuel Cells for Energy Generation
™What is the structure of H+ ions in water?
™How to design membranes that could transport H+ ions?
™How to stop methanol or hydrogen from moving across
the membrane?
10
Photovoltaic Cells
Efficiency of Photovoltaic Cells Depend on
™Absorption in Solar Spectrum
™Charge Separation Efficiency
™Charge Mobility
11
Elusive Heterojunctions
12
PV Cells: Fundamental Questions
PV Cells:
Efficient, cost effective, environmentally friendly energy production
™How to assemble semiconductors for efficient charge separation
and mobility? How to assemble heterojunctions without macrophase
segregation (interplay of intermolecular forces)?
™Design of molecules and macromolecules for efficient capture of
solar energy. Strategies to capture Solar Energy
™Design and synthesis of transparent semiconductors to replace
expensive Indium tin oxide
13
National Chemical Energy Research Network (NCERN)
http://www.chem.umass.edu/masscrest/NCERN/
National Chemical Energy Research Network (NCERN) is designed to facilitate communication between energy researchers and the public, and provides enhanced public understanding, visibility, and publicity to chemical energy research. It is a public portal for educators, students and public to get accurate information on topics related to chemical energy. NCERN is also a dynamic interface between research centers engaged in chemical energy and the surrounding community that is impacted by that research. 14
National Chemical Energy Research Network (NCERN)
™Education and Outreach
™Energy Blogs
™Energy Wiki
™Research
™Technology
15
Contact Info:
http://www.chem.umass.edu/masscrest/NCERN/
http://www.chem.umass.edu/masscrest/
http://www.umass.edu/research/energy/
dv@chem.umass.edu
fermann@chem.umass.edu
16
New Membrane Materials at Centre for Fueling the Future
H
N
N
1. Controlling distance between the sites
2. Controlling the assembly of molecules
3. Creating new molecules for proton transport
H
N
N
H
N
N
Benzimidazole
http://www.chem.umass.edu/masscrest/fuelingthefuture/
17
Efficiency of Current Photovoltaics Devices
Source: Basic Research Energy Needs for Solar Energy
Utilization, US Department of Energy
18
Fuel Cells in Develpment
Fuel Cell Type
Electrolyte
Polymer
CF(CF2)nOCF2SO3−
Fuel: H2
NAFION
Alkaline
KOH gel
Cond. Ion
H+
hydrated
Temp. (ºC)
Features
0–80
High power density, Pt
catalyst, must be kept wet,
poisoned by CO, S, Cl
OH−
90
High power density, cannot
tolerate CO2, impurities
(NASA)
H3PO4
H+
250
Medium power density, Pt
catalyst, sensitive to CO,
poisoned by S, Cl
Molten
carbonate
Fuel: H2
Li2CO3 / K2CO3
CO32−
650
Low power density, Ni
catalyst, needs CO2 recycle
Solid oxide
Fuel: CH4, H2
Zr0.92Y0.08O1.96
O2−
Direct methanol
CF(CF2)nOCF2SO3-
H+
hydrated
Fuel: CH3OH
NAFION
Fuel: H2
Phosphoric acid
Fuel: H2
700–1,000
0–80
Medium-to-high power
density, much less
sensitive to impurities
Medium power density, low
efficiency, high Pt content.
Sensitive to S and Cl
impurities
19
Efficiency and Cost
Source: Basic Research Energy Needs for Solar Energy
Utilization, US Department of Energy
20
Solar Insolation
100
Photons per square meter per second per nm of bandwidth
6E+18
90
5E+18
80
AM 0
70
4E+18
Integrated
Photon Flux
60
50
3E+18
40
2E+18
30
20
1E+18
AM 1.5G
4 eV
0E+00
280
380
3 eV
480
10
2 eV
580
680
1.5 eV
780
880
1 eV
980
Wavelength (nm)
1080 1180 1280 1380 1480
0
21
Shockley-Queisser Limit: Better Photon Management
Source: Basic Research Energy Needs for Solar Energy Utilization,
US Department of Energy
22
P-N junctions and Photovoltaic Cells
Conventional Solar Cell
Light
Light
electrons
Organic Heterojunction Solar Cell
holes
Anode
Cathode
h+
n-type
Donor
exciton
e-
Cathode
p-type
Acceptor
Anode
Spanggaard, H.; Krebs, F. C. "A brief history of the development of organic and
polymeric photovoltaics," Solar Energy Materials and Solar Cells 2004, 83, 125146.
23
Templated-Directed Electrodeposition
‘a simple, high‐throughput, and cost‐effective procedure...’ to create 1D nanostructures
Xia, Y. N.; Yang, P. D.; Sun, Y. G.; Wu, Y. Y.; Mayers, B.; Gates, B.; Yin, Y. D.; Kim, F.; Yan, Y. Q. "One-Dimensional Nanostructures: Synthesis,
Characterization, and Applications," Advanced Materials 2003, 15, 353-389.
24
Templated-Directed Cadmium Selenide Electrodeposition
25
UMass Researchers Focus on Efficient PV Cells
Prof. Thayumanavan, Chemistry
Prof. Thomas Russell, PSE
26
UMass Researchers Focus on Efficient Morphologies
27
Hydrogen Production from Carbon Sources
Methane
CH4 (g) + H2O (g) Æ CO2 (g) + 4 H2
At 650 °C, the reaction is spontaneous.
Water- Gas Shift Reaction
CO + H2O Æ CO2 + H2
Expected H2 Demand in 2040
™150 Mtons
From Coal
C + H2O Æ CO + H2
C + 2 H2O Æ CO2 + 2H2
Current Production
™10 Mtons
™1 ton of H2 = 5 tons of CO2
28
Breaking Water Using Enzymes –UMass at the Forefront
Hydrogenase
Clostridium pasteuianum Fe-Fe H2ase-I and
Desulfovibrio gigas NiFe H2ase.
29
Hydrogenase as a catalyst of H2 Production
Figure 4: A plot of the amount of hydrogen produced with respect to time in a hydrogenase encapsulated in a solgel glass.
Maroney (UMass Amherst) and Elgren (Hamilton College)
30
Hydrogen Generation through Nanobiotechnology
Chart 1
D. Venkataraman and Maroney
31
Hydrogen Storage and Transport : Sodium Borohydride
“Hydrogen on demand”
30% NaBH4
3% NaOH
67% Water
32
Hydrogen Storage and Transport
Source: National Renewable Energy Laboratory, USA