PEM Fuel Cell Electrocatalysts and Catalyst Layers (eBook)

Dr Jiujun Zhang is a Senior Research Officer and PEM Catalysis Core Competency Leader at the National Research Council of Canada Institute for Fuel Cell Innovation (NRC-IFCI). Dr Zhang has over twenty-six years of R&D experience in theoretical and applied electrochemistry, including over twelve years of fuel cell R&D (among these six years at Ballard Power Systems and four years at NRC-IFCI), and three years of electrochemical sensor experience. Dr Zhang holds seven adjunct professorships, including one at the University of Waterloo and one at the University of British Columbia. His research is based on: low/non-Pt cathode catalyst development with long-term stability for catalyst cost reduction; preparation of novel material-supported Pt catalysts through ultrasonic spray pyrolysis; catalyst layer/cathode structure; fundamental understanding through first principles theoretical modeling; catalyst layer characterization and electrochemical evaluation; and preparation of cost-effective MEAs for fuel cell testing and evaluation. Dr Zhang has co-authored more than 140 research papers published in refereed journals and holds over ten US patents. He has also produced in excess of seventy industrial technical reports. Dr Zhang is an active member of The Electrochemical Society, the International Society of Electrochemistry, and the American Chemical Society.

Preface 5
Contents 8
1 PEM Fuel Cell Fundamentals 21
1.1 Overview 21
1.2 Thermodynamics 51
1.3 Reaction Kinetics 73
References 99
2 Electrocatalytic Oxygen Reduction Reaction 108
2.1 Introduction 108
2.2 Oxygen Reduction on Graphite and Carbon 120
2.3 Oxygen Reduction Catalyzed by Quinone and Derivatives 128
2.4 Oxygen Reduction on Metal Catalysts 129
2.5 ORR on Macrocyclic Transition Metal Complexes 136
2.6 ORR Catalyzed by Other Catalysts 141
2.7 Superoxide Ion 144
2.8 Conclusions 148
References 148
3 Electrocatalytic H2 Oxidation Reaction 154
3.1 Introduction 154
3.2 Electrooxidation of Hydrogen [5, 6, 9, 10] 155
3.3 Electrocatalysis of Hydrogen Oxidation 168
3.4 Conclusions 178
References 178
4 Electrocatalytic Oxidation of Methanol, Ethanol and Formic Acid 184
4.1 Introduction 184
4.2 Reaction Pathways, Catalyst Selection, and Performance: Example Analysis 191
4.3 Advances in Anode Catalyst Layer Engineering: Example Analysis 249
4.4 Conclusions 288
References 289
5 Application of First Principles Methods in the Study of Fuel Cell Air-Cathode Electrocatalysis 307
5.1 Introduction 307
5.2. Background 308
5.3 Surface Adsorption 311
5.4 Activation Energy 324
5.5 Thermodynamic Properties: Reversible Potential and Reaction Energy 329
5.6 Study of Non-noble Catalysts 334
5.7 Summary 342
References 342
6 Catalyst Contamination in PEM Fuel Cells 348
6.1 Introduction 348
6.2 Anode Catalyst Layer Contamination 348
6.3 Cathode Catalyst Layer Contamination 356
6.4 Additive Effects of Anode and Cathode Contamination 366
6.5 Summary 367
References 368
7 PEM Fuel Cell Catalyst Layers and MEAs 372
7.1 Fundamentals of Catalyst Layers 372
7.2 Principles of Membrane Electrode Assembly (MEA) 386
7.3 Conclusions 391
References 391
8 Catalyst Layer Modeling: Structure, Properties and Performance 398
8.1 Introduction 398
8.2 Understanding Structure and Operation of Catalyst Layers 400
8.3 State of the Art in Theory and Modeling: Multiple Scales 412
8.4 Structure Formation of Catalyst Layers and Effective Properties 415
8.5 Performance Modeling and Optimization Studies 429
8.6 Comparison and Evaluation of Catalyst Layer Designs 450
8.7 Summary and Outlook 455
References 456
9 Catalyst Synthesis Techniques 464
9.1 Introduction 464
9.2 Catalysis Synthesis Methods 464
9.3 Particle Size and Shape Control 475
9.4 Bi-metallic Catalysts 485
9.5 Non-noble Metal Catalyst Synthesis 491
References 496
10 Physical Characterization of Electrocatalysts 503
10.1 Introduction 503
10.2 Analysis of Composition and Phase of Catalyst 504
10.3 Measurement of Physical Surface Area and Electrochemical Active Surface Area 514
10.4 Morphology of Catalysts and Their Active Components 521
10.5 The Structure and Crystallography of Surface and Small Active Component Particles 528
10.6 Analysis of the Stability of Catalysts by the Thermal Analysis Method 541
10.7 Other Structural Techniques for Characterizing the Bulk and Surface of Electrocatalysts 548
10.8 Conclusion 552
References 552
11 Electrochemical Methods for Catalyst Activity Evaluation 563
11.1 Electrochemical Cells 563
11.2 Brief Principles of Electrochemical Instrumentation 572
11.3 Cyclic Voltammetry 572
11.4 Rotating Disk and Rotating Ring-disk Electrode Techniques 583
11.5 Electrochemical Impedance Spectroscopy 589
11.6 Current Interruption and Current Pulse Techniques 601
11.7 Steady-state I-V Polarization 604
11.8 Durability Evaluation 608
11.9 Summary 618
List of Symbols 618
References 620
12 Combinatorial Methods for PEM Fuel Cell Electrocatalysts 624
12.1 Introduction 624
12.2 Combinatorial Methods for Fuel Cell Electrocatalysis 627
12.3 Combinatorial Discoveries of Fuel Cell Electrocatalysts 637
12.4 Conclusions 643
References 644
13 Platinum-based Alloy Catalysts for PEM Fuel Cells 646
13.1 Introduction 646
13.2 Pt-based Alloy Catalysts for PEM Fuel Cell Cathodes 647
13.3 Pt-based Alloy Catalysts for DMFC Anodes 658
13.4 Concluding Remarks 665
References 666
14 Nanotubes, Nanofibers and Nanowires as Supports for Catalysts 670
14.1 Introduction 670
14.2 Synthesis and Characterization of Carbon Nanotubes, Nanofibers and Nanowires 672
14.3 Synthesis and Characterization of Pt Catalysts Supported on Carbon Nanotubes, Carbon Nanofibers and Metal Oxide Nanowires 680
14.4 Activity Validation of the Synthesized Catalysts in a Fuel Cell Operation 708
14.5 Stability of Carbon Nanotubes and Nanofibers-based Fuel Cell Electrodes 715
14.6 Conclusions and Future Perspective 717
Acknowledgements 718
References 719
15 Non-noble Electrocatalysts for the PEM Fuel Cell Oxygen Reduction Reaction 730
15.1 Introduction 730
15.2. Transition Metal Macrocycles for the Oxygen Reduction Reaction 731
15.3. Non-noble Transition Metal Carbides and Nitrides for the ORR 740
15.4 Transition Metal Chalcogenides for the ORR 749
15.5 Metal Oxides for the ORR 757
15.6 Conclusions 763
References 763
16 CO-tolerant Catalysts 773
16.1 Introduction 773
16.2 Mechanisms of CO Tolerance 778
16.3 Development of CO-tolerant Catalysts 795
16.4 Preparation of CO-tolerant Catalysts 819
16.5 Conclusions 823
Acknowledgements 825
References 825
17 Reversal-tolerant Catalyst Layers 849
17.1 Introduction 849
17.2 Cell Voltage Reversal 852
17.3 Development of Reversal-tolerant Catalyst Layers 859
17.4 Conclusions 870
Acknowledgements 870
References 870
18 High-temperature PEM Fuel Cell Catalysts and Catalyst Layers 875
18.1 Opportunities and Challenges for High-temperature PEM Fuel Cells 875
18.2 Catalysts for High-temperature PEM Fuel Cells 882
18.3 Summary 898
References 898
19 Conventional Catalyst Ink, Catalyst Layer and MEA Preparation 903
19.1 Introduction 903
19.2 Principles of Gas Diffusion Electrodes and MEA Structures 903
19.3 Catalyst Layer 907
19.4 Preparation of the MEA 925
19.5 Summary and Outlook 925
References 926
20 Spray-based and CVD Processes for Synthesis of Fuel Cell Catalysts and Thin Catalyst Layers 931
20.1 Introduction 931
20.2 Spray Pyrolysis Approach 933
20.3 Deposition of Catalyst Layer by CVD 943
20.4 Flame-based Processing 955
20.5 Summary 972
Acknowledgements 972
References 972
21 Catalyst Layer/MEA Performance Evaluation 978
21.1 Introduction 978
21.2 Theoretical Analysis 979
21.3 Physical Chemistry Evaluation of Catalyst Layer 986
21.4 Catalyst Layer Evaluation in a Half-cell 991
21.5 MEA Evaluation by the Single-cell Test 999
21.6 Lifetime/Durability Testing of the MEA 1007
21.7 Conclusions 1010
References 1010
22 Catalyst Layer Composition Optimization 1016
22.1 Catalyst Layer Materials Selection and Evaluation 1016
22.2 Fabrication Optimization Processes for the Catalyst Layer of MEAs 1029
22.3 MEA Performance Verification with its Catalyst Layer Fabrication Optimization Process 1044
References 1046
23 Catalyst Layer Degradation, Diagnosis and Failure Mitigation 1054
23.1 Introduction 1054
23.2 Diagnosis of Catalyst Layer Degradation: Fuel Cell Failure Analysis 1057
23.3 Anode Catalyst Layer Degradation 1069
23.4 Cathode Catalyst Layer Degradation 1079
23.5 Summary 1100
References 1102
Acronyms and Abbreviations 1108
Contributor Biographies 1115
Author Index 1128
Subject Index 1129