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Air Electrode in Hydrogen Fuel Cell. Mentors: Dr. Flanders & Dr. Sorenson. Physics REU 2012 Diana Gutierrez Zedano. Hydrogen Fuel Cell. external circuit. Air electrode. cathode. anode. H 2 source. H 2 2H + + 2e -. O 2 in air. O 2 + 4e - 2O 2-. reduction. - PowerPoint PPT Presentation
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Air Electrode in Hydrogen Fuel Cell
Physics REU 2012
Diana Gutierrez ZedanoMentors: Dr. Flanders & Dr. Sorenson
Hydrogen Fuel Cell
H2 2H+ + 2e-
O2 in air
cathodeanode
H2 source
O2 + 4e- 2O2-
H+ O2- 2H+ + O2- H2O
Air electrodeexternal circuit
electrolyte varies
reduction
green waste
Cross Sectional View of the Air Electrode
Bjorn Winther-Jensen et all. High Rates of Oxygen Reduction over a Vapor Phase–Polymerized PEDOT Electrode. Science. August 2008: 671-674
Gore-tex Gold PEDOT
Carbon Aerosol Gel
Gore-tex Fabric
Hydrophobic - keeps electrolyte from going through the pores
Porous - “breathable”
Academy of Art University of San Francisco
Carbon Aerosol Gel
Acetylene or ethylene with oxygen are kept in a fuel rich chamber and ignited by a spark. This produces an incomplete combustion which allows for the aggregation of carbon particles
Pores confined within fractal structure
Black color (like PEDOT): use Raman spectrum to differentiate Bands: D 1330, G 1580, G’ 2646
Raman Spectrum for Carbon Aerosol Gel
Wavenumber (cm-1)
1000 1500 2000 2500 3000
Inte
nsit
y (a
u)
-5
0
5
10
15
20
PEDOT poly(3,4-ethylenedioxythiophene)
Low electrical conductivity: gold layer is needed
O2 reduction catalyst
Wikipedia
Not sensitive to carbon monoxide Raman Spectrum Band: Double carbon bond
Raman Spectrum for PEDOT
Wavenumber (cm-1)
500 1000 1500 2000
Inte
nsit
y (a
u)
-100
0
100
200
300
400
500
600
700
O2 + 4e- 2O2-
Experimental Process Carbon aerosol gel is pressed on Goretex
Resistance varies from 25 to 3 kilo ohms
Electro deposition of gold on carbon-coated Goretex. 20 mM HAuCl4
2 V DC
Electro polymerization of PEDOT film on gold-coated Goretex. 10 mM EDOT and 20 mM PSS 2 V DC
Raman Spectrum for Air Electrode
Wavenumber (cm-1)
1000 1500 2000 2500 3000
Inte
nsit
y (a
u)
0
10
20
30
40
50
60Carbon Aerosol GelGlass Au PEDOTGoretex Carbon Au PEDOT
Testing Air Electrode
Pt Counter Electrode
Working Electrode
Copper tape
Half of the hydrogen fuel cell Electrolyte: 1M H2SO4
H2SO4
O2 + 4e- 2O2-
O2 in air
Air electrode test dataTrial
Applied Voltage (V)
-0.8 -0.6 -0.4 -0.2 0.0 0.2 0.4 0.6 0.8
-I (
mA
)
-0.2
-0.1
0.0
0.1
0.2
0.3
0.4
Goretex-carbon-Au-PEDOTGoretex-Carbon-AuGoretex-CarbonGoretex
Future Plans Air electrode needs to be tested in an oxygen free
environment. Work out a method to enhance the amount of PEDOT
deposition
Acknowledgments
I would like to thank: NSF for funding Dr. Flanders and Dr. Sorenson who guided me through the
project Govind Paneru for teaching me the skills I needed for my project Dr. Flanders, Dr. Sorenson and Arjun Nepal who made the
carbon aerosol gel sample Dr. Weaver and Dr. Corwin for coordinating the program