Table Of Contents:
Series Preface vii
Preface ix
Editors xiii
Contributors xvii

PEM Fuel Cell Principles and Introduction to Contamination Issues 1(52)

Shanna Knights

Introduction 3(12)

What Is a Fuel Cell? 4(1)

Benefits of Fuel Cells 4(1)

Energy Efficiency 4(2)

Greenhouse Gas Reduction 6(1)

Brief History of Fuel Cells 7(2)

Types of Fuel Cells 9(1)

Polymer Electrolyte Membrane (PEM) 9(3)

Alkaline Fuel Cell (AFC) 12(1)

Phosphoric Acid Fuel Cell 13(1)

Molten Carbonate Fuel Cell 13(1)

Solid Oxide Fuel Cell 14(1)

PEM Fuel Cell Description 15(4)

Fuel Cell Reactions 15(1)

Fuel Cell Schematic 16(1)

Fuel Cell Components 16(1)

Proton Exchange Membrane 16(1)

Catalyst, Catalyst Layer 17(1)

Gas Diffusion Layers Includin Microporous Layers 18(1)

Bipolar or Flowfield Plates 18(1)

Fuel Cell Stack 19(1)

Applications 19(2)

Fuel Cell Performance 21(5)

Open Circuit Voltage and the Nernst Equation 21(1)

Overpotential 22(1)

Activation Polarization 23(1)

Exchange Current Density, iα and Rate Constant, k0 23(1)

Tafel Equation 24(1)

Butler-Volmer Equation 24(1)

Charge Transfer Resistance, Rct 24(1)

Concentration Polarization or Mass Transport Losses 25(1)

Ohmic Losses 25(1)

Anode Polarization 26(1)

Fuel Cell Diagnostics 26(4)

Polarization Curve 26(1)

Steady State Testing 27(1)

Duty Cycle Testing 27(1)

Oxygen Testing 27(1)

Voltage Decay 28(1)

AC Impedance 28(1)

Cyclic Voltammetry 29(1)

Single Cell versus Stack Testing 29(1)

Accelerated Durability Testing 29(1)

Fuel Cell Operating Conditions 30(2)

Temperature 30(1)

Pressure 31(1)

Humidity 31(1)

Fuel Cell Degradation Modes 32(7)

Cathode Degradation 33(1)

Catalyst Degradation (Pt Dissolution, Agglomeration, Ostwald Ripening) 33(1)

Cathode Corrosion 34(2)

Membrane Degradation 36(1)

Chemical Degradation 36(2)

Mechanical and Thermal Degradation 38(1)

Anode Degradation 38(1)

Introduction to Contamination Issues in Fuel Cells 39(9)

Contamination Sources and Chemical/ Electrochemical Reactions 40(1)

Cathode Contaminants 40(1)

Anode Contaminants 41(1)

Anionic Contaminants 42(1)

Membrane Contamination 42(1)

Fuel Cell Contamination Modeling 43(1)

Cathode Contamination Modeling 43(1)

Anode Contamination Modeling 44(1)

Membrane Contamination Modeling 45(1)

Impurity Mitigation Strategies 46(2)

Summary 48(5)

References 49(4)

Fuel Cell Contaminants: Sources and Chemical/Electrochemical Reactions 53(32)

Jianlu Zhang

Zheng Shi

Hui Li

Jiujun Zhang

Introduction 53(1)

Anode Contaminants/Impurities and Their Basic Chemistry 54(12)

COx and Their Basic Chemistry 54(1)

Sources of CO and CO2 54(2)

Chemistry of CO 56(6)

Chemistry of CO2 62(1)

H2S and Its Basic Chemistry 62(2)

NH3 and Its Basic Chemistry 64(2)

Cathodic Contaminants/Impurities and Their Basic Chemistry 66(7)

COx and Their Basic Chemistry 67(1)

Sources of COx 67(1)

Chemistry of COx 68(1)

SOx and Their Basic Chemistry 68(1)

NOx and Their Basic Chemistry 69(2)

VOCs and Their Basic Chemistry 71(1)

NH3 and Its Basic Chemistry 72(1)

Membrane Contaminants/Impurities and Their Basic Chemistry 73(1)

Anions and Their Chemistry 74(2)

Other Contamination Sources 76(1)

Summary 76(9)

References 77(8)

Cathode Contamination 85(30)

Hui Li

Jianlu Zhang

Zheng Shi

Datong Song

Jiujun Zhang

Introduction 85(2)

Impacts of SOx 87(4)

Impacts of NOx 91(2)

Impacts of NH3 and H2S 93(2)

Impacts of VOCs 95(3)

Impacts of Multiple Contaminants 98(2)

Mitigation Strategies for Airside Contamination 100(1)

Example Analysis: Development of Cell Performance Predictor under the Influence of Toluene in the Air Stream 101(9)

Experimental 102(1)

Description of Semiempirical Models 102(4)

Results and Discussion 106(1)

Simulation of KCK and Kt 106(1)

Model Prediction 106(4)

Conclusions 110(1)

Summary 110(5)

Acknowledgments 111(1)

References 111(4)

Anode Contamination 115(36)

Daijun Yang

Jianxin Ma

Jinli Qiao

Introduction 116(1)

Hydrogen Production Processes 117(4)

Reforming of Hydrogen-Containing Fossil Fuel 118(2)

Electrolysis 120(1)

Purification of By-Product Hydrogen 121(1)

Sources of Key Impurities 121(3)

COx 123(1)

H2S 124(1)

NH3 124(1)

Impact of COx 124(12)

Preferential Adsorption of CO on Platinum 125(2)

Reduction of CO2 to CO 127(1)

Deleterious Effect of CO 127(1)

Severe Poisoning Impact of Trace Amounts of CO 127(3)

Temperature Effect 130(2)

Addition of Ruthenium as a Second Metal 132(1)

Impact of Anode CO on Cathode 133(1)

Impact of CO2 134(1)

Combined Impacts of CO and CO2 135(1)

Impact of H2S 136(4)

Adsorption Behavior of H2S 136(1)

Impact of H2S 137(1)

Cyclic Voltammetry Study 138(1)

Open Circuit Voltage Operation 139(1)

Impact of NH3 140(1)

Deleterious Effects of NH3 140(1)

Mechanism for the Impact of NH3 141(1)

Impact of Organic Compounds 141(1)

Mitigation Methods for Anode Contamination 142(2)

Impurity-Tolerant Catalyst 142(1)

Elevated Temperature Operation 143(1)

Chemical Oxidant Bleed 143(1)

Electrochemical Removal 144(1)

Summary 144(7)

Acknowledgments 145(1)

References 145(6)

Membrane Electrode Assembly Contamination 151(28)

S. R. Dhanushkodi

M. W. Fowler

A. G. Mazza

M. D. Pritzker

Introduction 151(1)

Background 152(5)

Membrane Chemistry 152(1)

Types of MEA Membrane Degradation 153(1)

Concept of "Reliability, Durability, and Stability" 154(1)

Perspectives on MEA Integrity 154(1)

Chemical and Mechanical Degradation 155(1)

Mechanisms of Membrane Failure by Chemical Attack 155(1)

Mechanism of Membrane Failure by Mechanical Attack 156(1)

Membrane Contamination 157(15)

Contaminants in Fuel Gas Stream 157(1)

Contaminants in Air Stream 158(1)

NOx Contamination 159(2)

SOx and Hydrogen Sulfide Contamination 161(3)

CO2 and CO Contamination 164(3)

Ammonia Contamination 167(2)

Metal Ion Contamination 169(2)

Si Contamination 171(1)

Dilution Effects and Coolant Contamination 171(1)

Conclusions 172(7)

Acknowledgments 173(1)

References 173(6)

Cathode Contamination Modeling 179(30)

Zheng Shi

Datong Song

Hui Li

Jianlu Zhang

Zhong-Sheng Liu

Jiujun Zhang

Introduction 179(2)

Oxygen Reduction Mechanism 181(4)

Review of Oxygen Reduction Kinetic Models 185(1)

Cathode Contamination Model 186(6)

Cathode Contamination Reaction Mechanism 186(1)

Cathode Contamination Model 187(5)

Model Validation and Results Discussion 192(10)

Toluene Contamination Mechanism 192(1)

Experiment 193(1)

Oxygen Concentration 193(1)

ORR Parameters 194(2)

Modeling Results and Discussion 196(6)

Discussion of Other Cathode Contamination Models 202(2)

Summary 204(5)

References 205(4)

Anode Contamination Modeling 209(84)

Nada Zamel

Xianguo Li

Introduction 210(3)

PEM Fuel Cell Components 211(2)

Carbon Monoxide Poisoning 213(41)

Review of CO Modeling in Literature 213(4)

CO Contamination and Mitigation Methods 217(1)

Reaction Pair Mechanism of CO Poisoning 217(1)

Mitigation Methods 218(6)

Modeling of CO Poisoning 224(1)

Catalyst Layer Model 224(7)

Transport in the Gas Diffusion Layer 231(1)

Transport in the Flow Channel and Bipolar Plate 232(3)

Estimation of Flow Channel Concentration 235(5)

Validation Procedure 240(1)

Results and Discussion 241(1)

CO Poisoning 241(10)

Oxygen Bleeding 251(1)

CO-Tolerant Catalysts 252(2)

Summary 254(1)

CO2 Contamination Kinetics 254(5)

CO2 Reaction Kinetics 255(2)

Discussion 257(2)

Poisoning of S Compounds 259(34)

Review of H2S Modeling in Literature 259(3)

H2S Contamination 262(1)

Mechanism of H2S Poisoning 263(1)

Modeling of H2S Poisoning 264(1)

Transport in the Catalyst Layer 264(3)

Transport in the Gas Diffusion Layer 267(1)

Transport in the Flow Channel and Bipolar Plate 268(1)

Validation Procedure 269(1)

Results and Discussion 269(4)

Summary 273(20)

Membrane Contamination Modeling 293(46)

Thomas E. Springer

Brian Kienitz

Introduction 294(2)

Membrane Model: Single Cation Issues 296(7)

Water Content 296(3)

Water Diffusion Flux 299(1)

Conductivity 300(2)

Water Electroosmotic Drag 302(1)

Membrane Model: Multiple Cation Issues 303(5)

Ammonium Ion Contamination Example 304(1)

Migration 305(1)

Ion Diffusion 306(1)

Combined Ion and Water Fluxes 306(2)

Transport Equations 308(2)

Continuity Equation 308(1)

Flux Equations in Scaled Solution Variables 309(1)

Boundary Conditions 310(1)

Solution Methods and Predictions 310(12)

Steady State Analytic Solution 310(2)

Predictions from Analytic Steady State Solution without Water 312(2)

Time Domain Numerical Solutions with Water 314(1)

Predictions from Time Domain Numerical Solution with Water 315(1)

Dynamic Resistance Effects 316(1)

Frequency Domain Equations 317(2)

Impedance Predictions 319(3)

Electrodes and Nernst Potential 322(9)

Electrode Impedance 325(1)

Model Comparison to Experiment 326(5)

Conclusions 331(1)

Appendix: Concentrated Solution Theory 332(7)

Acknowledgments 334(1)

Nomenclature 335(1)

References 336(3)

Impurity Mitigation Strategies 339(62)

Cunping Huang

Xinyu Huang

Marianne Rodgers

Introduction 340(1)

Hydrogen Production Technologies and Hydrogen Purification 340(33)

Overview of Hydrogen Production Technologies 340(2)

Hydrogen Production from Natural Gas and Hydrocarbons 342(10)

Hydrogen Production from Biomasses 352(1)

Hydrogen Production from Coal 353(5)

Hydrogen Production from Water 358(4)

Overview of Hydrogen Purification Technologies 362(1)

Hydrogen Sulfide Removal Technologies 362(3)

Carbon Monoxide Removal Technologies 365(5)

Carbon Dioxide Removal Technologies 370(2)

Summary 372(1)

System Level Mitigation Strategies 373(7)

Fuel Cell System and Source of Contaminants 373(1)

Materials Selection and Screening 374(1)

Prevention of Contaminants from Entering a Fuel Cell System 375(2)

Continuous Elimination of Contaminants within a Fuel Cell System 377(1)

Periodic Decontamination Procedure to Flush Out Contaminants from the Fuel Cell System 378(2)

Onboard Fuel Cell Impurity Mitigation Strategies 380(21)

Introduction 380(1)

Fuel Side Contamination Mitigation 381(1)

CO Mitigation 381(6)

H2S Mitigation 387(1)

Air Side Contamination Mitigation 388(1)

CI- Mitigation 389(1)

Sulfur Compounds Mitigation 389(1)

NO2 Mitigation 390(1)

Ammonia Mitigation 390(1)

Summary and Conclusion 391(1)

References 392(9)
Index 401