Next Generation Fuel Cells: Anion Exchange Membrane Fuel Cells Presented By Jerry Gilligan Primary Source Material Lu, S., Pan, J., Huang, A., Zhuang, L., and Lu, J. “Alkaline polymer electrolyte fuel cells completely free of noble metal catalysts.” Proc. Natl. Acad. Sci , 52; Image: Quarternary Amine Polysulfone Lu et. al.; Proc. Natl. Acad. Sci , 52;

The Transportation Problem Hydrocarbon Fuel CO 2 Heat Loss O2O2 Heat Work Internal Combustion Engine ~28% of US energy consumption is in the transportation sector, and 95% of that demand is met by petroleum based hydrocarbon fuels. Image: Jaguar XK Apple Inc.; “Desktop Images.” Source: US EIA US EIA; US Energy Info. Admin.

Why Fuel Cells? Hydrocarbon Fuel CO 2 Heat Loss O2O2 Heat Work Internal Combustion Engine Oxidizing Agent H2OH2O Reducing Agent Electrical Work Fuel Cell Zaidi, J. et. al.; 2010.

Why Fuel Cells? Hydrocarbon Fuel CO 2 Heat Loss O2O2 Heat Work Internal Combustion Engine Oxidizing Agent Reducing Agent Electrical Work Fuel Cell Inefficient CO 2 Producer Hydrocarbon Consumer More Efficient Benign Byproducts Abundant Fuel H2OH2O Zaidi, J. et. al.; 2010.

Efficiency Comparison Hydrocarbon Fuel CO 2 Heat Loss O2O2 Heat Work Internal Combustion Engine Oxidizing Agent Reducing Agent Electrical Work Fuel Cell H2OH2O Energy Efficiency Theoretical: 37% (Steel) Real: 20% (Steel) Energy Efficiency Theoretical: 60-70% Real: 50-60% Zaidi, J. et. al.; 2010.

Inefficiency Sources Hydrocarbon Fuel CO 2 Heat Loss O2O2 Heat Work Internal Combustion Engine Oxidizing Agent Reducing Agent Electrical Work Fuel Cell H2OH2O Energy Efficiency Theoretical: 37% (Steel) Real: 20% (Steel) Energy Efficiency Theoretical: 60-70% Real: 50-60% Heat Loss Resistance Zaidi, J. et. al.; 2010.

The Fuel Cell Vehicle Image: Fuel Cell Equinox Fray, D.; “DoITPoMS: Fuel Cells.” University of Cambridge. Refuels at Pumping Stations, Runs on Air and Hydrogen, and Has Momentary Output Required for Merging.

Types of Fuel Cells SOFC – Solid Oxide MCFC – Molten Carbonate AFC – Alkaline/Anionic PAFC – Phosphoric Acid PEMFC – Polymer Electrolyte Membrane Image: Fuels and Fuel Cells Fray, D.; “DoITPoMS: Fuel Cells.” University of Cambridge.

Alkaline Fuel Cells SOFC – Solid Oxide MCFC – Molten Carbonate AFC – Alkaline/Anionic PAFC – Phosphoric Acid PEMFC – Polymer Electrolyte Membrane Image: Fuels and Fuel Cells Fray, D.; “DoITPoMS: Fuel Cells.” University of Cambridge.

AFCs vs PEMFCs AFC – Alkaline Fuel Cell Requires no Pt/Noble Metal Catalyst More Efficient Carbonate Poisoning Problem PEMFC – Proton Exchange Membrane Fuel Cell Requires Pt Catalyst Known Exchange Membranes with High Conductivity Image: Fuels and Fuel Cells Fray, D.; “DoITPoMS: Fuel Cells.” University of Cambridge.

AFCs: Alkaline Reactions Anode (ox): 2 H OH - → 4 H 2 O + 4e - Raney Ni Catalyst Cathode (red): O H 2 O + 4e - → 4 OH - Ag Catalyst Overall: O 2 + 2H 2 → 2H 2 O

Image: Shuttle AMFC Cell Stack Fray, D.; “DoITPoMS: Fuel Cells.” University of Cambridge. Current Uses: Submarines Military Applications NASA’s Space Shuttle Future NASA Craft The technology needs to overcome significant hurdles to break in to the commercial transportation marketplace. AFC Applications

AFCs vs PEMFCs AFC – Alkaline Fuel Cell Requires no Pt/Noble Metal Catalyst Carbonate Poisoning Problem PEMFC – Proton Exchange Membrane Fuel Cell Requires Pt Catalyst Known Exchange Membranes with High Conductivity Image: Fuels and Fuel Cells Fray, D.; “DoITPoMS: Fuel Cells.” University of Cambridge.

AFCs: CO 2 Poisoning Mechanism From O 2 (Cathode): O H 2 O + 4e - → 4 OH - CO 2 + OH - → HCO 3 - Membrane Crossover: [HCO 3 - ] < [OH - ] To Air (Anode): 2 H OH- → 4 H 2 O + 4e - No CO 2 Poisoning Pure O 2

From O 2 (Cathode): O H 2 O + 4e - → 4 OH - CO 2 + OH - → HCO 3 - Membrane Crossover: [HCO 3 - ] < [OH - ] To Air (Anode): 2 H OH- → 4 H 2 O + 4e - No CO 2 Poisoning Pure O 2 AFCs: CO 2 Poisoning Mechanism

From Air (Cathode): O H 2 O + 4e - → 4 OH - CO 2 + OH - → HCO 3 - Membrane Crossover: [HCO 3 - ] > [OH - ] To Air (Anode): 2 HCO 3 - → 2 OH CO 2 H OH - → 2e - + 2H 2 O CO 2 Poisoning Ph Change, Reduced Operation, Precipitation of Carbonates Air AFCs: CO 2 Poisoning Mechanism

From Air (Cathode): O H 2 O + 4e - → 4 OH - CO 2 + OH - → HCO 3 - Membrane Crossover: [HCO 3 - ] > [OH - ] To Air (Anode): 2 HCO 3 - → 2 OH CO 2 H OH - → 2e - + 2H 2 O CO 2 Poisoning Ph Change, Reduced Operation, Precipitation of Carbonates Air AFCs: CO 2 Poisoning Mechanism

From Air (Cathode): O H 2 O + 4e - → 4 OH - CO 2 + OH - → HCO 3 - Membrane Crossover: [HCO 3 - ] > [OH - ] To Air (Anode): 2 HCO 3 - → 2 OH CO 2 H OH - → 2e - + 2H 2 O CO 2 Poisoning Ph Change, Reduced Operation, Precipitation of Carbonates Air AFCs: CO 2 Poisoning Mechanism

From Air (Cathode): O H 2 O + 4e - → 4 OH - CO 2 + OH - → HCO 3 - Membrane Crossover: [HCO 3 - ] > [OH - ] To Air (Anode): 2 HCO 3 - → 2 OH CO 2 H OH - → 2e - + 2H 2 O CO 2 Poisoning Ph Change, Reduced Operation, Precipitation of Carbonates Air AFCs: CO 2 Poisoning Mechanism

From Air (Cathode): O H 2 O + 4e - → 4 OH - CO 2 + OH - → HCO 3 - Membrane Crossover: [HCO 3 - ] > [OH - ] To Air (Anode): 2 HCO 3 - → 2 OH CO 2 H OH - → 2e - + 2H 2 O CO 2 Poisoning Ph Change, Reduced Operation, Precipitation of Carbonates Air AFCs: CO 2 Poisoning Mechanism

Image: APEFC Schematic Lu et. al.; Proc. Natl. Acad. Sci , 52; Anion Exchange Membrane Fuel Cell AEMFC Does not require Pt Catalyst Reduced CO 2 Poisoning Effect New Membranes!

QAPS Membrane Image: QAPS Structure Lu et. al.; Proc. Natl. Acad. Sci , 52; Quaternary Ammonium Polysulfone

OH - Conduction Image: QAPS Structure Lu et. al.; Proc. Natl. Acad. Sci , 52; Quaternary Ammonium Polysulfone Coordination of OH -

Image: APEFC Schematic Lu et. al.; Proc. Natl. Acad. Sci , 52; Fuel Cell Performance Membrane Conductivity – S/cm Power Density – 50 mW/cm 2 Temperature - 60°C Operation Time - >100 hrs no Degradation

Image: APEFC Schematic Lu et. al.; Proc. Natl. Acad. Sci , 52; Fuel Cell Performance Membrane Conductivity – S/cm Power Density – 50 mW/cm 2 Temperature - 60°C Operation Time - >100 hrs no Degradation Membrane Swelling

Image: APEFC Schematic Lu et. al.; Proc. Natl. Acad. Sci , 52; A Green Chemistry 12 Principles 1.Waste Prevention 2.Atom Efficiency 3.Human and Environmental Safety 4.Nontoxic 5.Reduce Auxiliary Substances 6.Minimize Energy Requirements 7.Renewable Feedstock 8.Reduce Derivatives 9.Use Catalytic Reagents 10.Low Environmental Lifetimes 11.Analytical Monitoring of Hazardous Substances 12.Minimize Potential for Danger

Image: APEFC Schematic Lu et. al.; Proc. Natl. Acad. Sci , 52; A Green Chemistry 12 Principles 1.Waste Prevention 2.Atom Efficiency 3.Human and Environmental Safety 4.Nontoxic 5.Reduce Auxiliary Substances 6.Minimize Energy Requirements 7.Renewable Feedstock 8.Reduce Derivatives 9.Use Catalytic Reagents 10.Low Environmental Lifetimes 11.Analytical Monitoring of Hazardous Substances 12.Minimize Potential for Danger

Next Generation Fuel Cells: Anion Exchange Membrane Fuel Cells Presented By Jerry Gilligan Primary Source Material Lu, S., Pan, J., Huang, A., Zhuang, L., and Lu, J. “Alkaline polymer electrolyte fuel cells completely free of noble metal catalysts.” Proc. Natl. Acad. Sci , 52; Image: Quarternary Amine Polysulfone Lu et. al.; Proc. Natl. Acad. Sci , 52; Works Cited 1. Fray, D.; “DoITPoMS: Fuel Cells.” University of Cambridge Press Lu, S., Pan, J., Huang, A., Zhuang, L., and Lu, J; “Alkaline polymer electrolyte fuel cells completely free of noble metal catalysts.” Proc. Natl. Acad. Sci. 105, 52; Gasteiger, H. and Schmidt, T.; 2011 “ECS PEFC Short Course.” Boston, ECS. 4. US EIA; “Annual Energy Review 2010.” US Energy Info.Admin Zaidi, J. et. al.; Polymer Membranes for Fuel Cells. Springer. New York, NY.