Platinum Monolayer Electrocatalysts

"This book describes a science and technology of a new type of electrocatalysts consisting of a single atomic layer of platinum on suitable supports. This development helped overcome three major obstacles--catalysts' cost, activity, and stability--for a broad range of fuel cell applications. The volume begins with a short introduction to the science of electrocatalysis, covering four reactions important for energy conversion in fuel cells. A description follows of the properties of metal monolayers on electrode surfaces, and underpotential deposition of metals. The authors then describe the concept of Pt monolayer electrocatalysts and its implications and their synthesis by galvanic displacement of less-noble metal monolayers and other methods. The main part of the book presents a discussion of catalysts' characterization and catalytic properties of Pt monolayers for the four main reactions of electrochemical energy conversion: oxygen reduction and oxidation of hydrogen, methanol and ethanol. The book concludes with a treatment of scale-up syntheses, fuel cell tests, catalysts' stability and application prospects. Provides a basic knowledge of electrocatalysis, an understanding of existing problems of fuel cells' power sources and their application; and a discussion of syntheses, characterization, and tuning catalytic properties of new groundbreaking Pt monolayer electrocatalysts Describes in detail examples for oxygen reduction, hydrogen, methanol and ethanol oxidation reactions Examines the enormous environmental benefit expected from automotive application of the H2/O2 fuel cell given its benign reaction products of electric current and water The first book on the important subject of platinum monolayer electrocatalysts, which has a major impact on research and development of new catalysts."--Prové de l'editor Preface 5 Contents 7 About the Authors 10 Chapter 1: Short Introduction to the Science of Electrocatalysis 12 1.1 Potential at Electrode–Electrolyte Interfaces 13 1.2 Electrical Double Layer 14 1.3 Charge-Transfer Reactions 17 1.3.1 Current-Potential Curves 19 1.3.2 Cyclic Voltammetry 21 1.3.3 Theories of Charge Transfers 23 References 24 Chapter 2: Electrocatalytic Reactions 26 2.1 Effect of Electrode Material: Volcano Plots 26 References 28 Chapter 3: Electrochemical Energy Conversion in Fuel Cells 30 3.1 Types of Fuel Cells 32 3.1.1 Proton Exchange Membrane Fuel Cell (PEMFC) 33 3.1.2 Alkaline Fuel Cells 34 3.1.3 Phosphoric Acid Fuel Cell 35 3.1.4 Solid Oxide Fuel Cells 35 3.1.5 Molten Carbonate Fuel Cells 36 References 36 Chapter 4: Studies of Electrocatalytic Reactions 37 4.1 Structural Effects in Electrocatalysis 37 4.2 Single-Crystal Electrodes 37 4.3 Preparation of Well-Ordered Single-Crystal Electrodes 41 4.4 Density Functional Theory Calculations in Electrocatalysis 42 References 43 Chapter 5: Important Electrosorption Reactions 44 5.1 Hydrogen Adsorption on Platinum Metals 44 5.2 Hydroxyl Adsorption and Oxide Formation 49 5.3 Underpotential Deposition (UPD) of Metals and Catalytic Properties of Surfaces Modified by Metal Adlayers 51 5.3.1 Oxidation of Small Organic Molecules on Surfaces Modified by UPD Adlayers 57 5.3.2 Hydrogen Evolution on Surfaces Modified by UPD Adlayers 58 5.3.3 Oxygen Reduction Reaction on Surfaces Modified by UPD Adlayers 60 References 62 Chapter 6: Important Electrocatalytic Reactions 65 6.1 Oxygen Reduction Reaction 65 6.1.1 The d-Band Theory of Surface Reactivity 71 6.2 Hydrogen Evolution Reaction 72 6.3 Hydrogen Oxidation Reaction 75 6.3.1 CO Tolerance 76 6.4 Methanol Oxidation Reaction 77 6.5 Ethanol Oxidation Reaction 79 6.6 Formic Acid Oxidation Reaction 82 6.7 Oxygen Evolution Reaction 84 References 86 Chapter 7: Platinum Monolayer Electrocatalysts 91 7.1 Concept of Pt Monolayer Electrocatalysts 91 7.2 Synthesis of Pt Monolayer Catalysts by Galvanic Displacement 93 7.3 Other Syntheses of Pt Monolayer Electrocatalysts 95 7.3.1 Pd-Pt Catalyst Synthesized in Ethanol 96 7.3.2 Synthesis of PtML by Surface Mediated Growth 97 7.3.3 Characterization of Pt Monolayer Electrocatalysts 98 7.4 In Situ FTIR and Synchrotron X-Ray Absorption Spectroscopies, and Hydrodynamic Rotating Disk Electrode Techniques 101 7.4.1 In situ FTIR Spectroscopy 101 7.4.2 X-Ray Absorption Spectroscopy 102 7.4.3 Rotating Disk Electrode 103 References 106 Chapter 8: Catalytic Properties of Pt Monolayer Electrocatalysts 109 8.1 Oxygen Reduction Reaction (ORR) 109 8.1.1 Pt Monolayer on Extended Areas Single Crystals 109 8.1.2 Pt Monolayer Shell on Nanoparticle Cores 113 8.1.3 Effects of Composition, Shape, and Size of Cores 115 8.1.3.1 Single Metal Nanoparticles Cores 119 8.1.3.2 Nanowires and Nanorods 121 8.1.3.3 Hollow Cores Supported Pt Monolayer Catalysts 123 8.1.3.4 Metallic Aerogels as Cores 126 8.1.3.5 Gold Clusters and Alloys, Promotion, and Stability Enhancing Effects 127 8.1.3.6 Intermetallic Compounds as Cores 132 8.1.4 Modifications of Pt Monolayer Surfaces 134 8.1.5 Modified Alloy Surfaces as Support for Pt Monolayers 136 8.1.6 Nitride-Stabilized Nonnoble Metal Core Components 137 8.2 Hydrogen Oxidation Reaction on Pt Monolayer Electrocatalysts and CO Tolerance 143 8.3 Methanol Oxidation on Platinum Monolayer Electrocatalysts 143 8.4 Ethanol Electrooxidation on Platinum Monolayer Electrocatalysts 149 8.4.1 Oxidation of Methanol and Ethanol on Modified Pt Monolayer Electrocatalysts Surfaces 152 8.4.2 Subsurface Modification of Cores 154 8.4.3 Reducing the Number of Low-Coordination Sites on Cores 156 References 158 Chapter 9: Performance Stability and Scale-Up Syntheses of Pt Monolayer Electrocatalysts 161 Reference 163 Chapter 10: Palladium Monolayer Electrocatalysts 164 References 167 Chapter 11: Prospects for Platinum and Platinum Group Metal Monolayer Electrocatalysts 168 References 169 Index 170 Front Matter ....Pages i-xii Short Introduction to the Science of Electrocatalysis (Radoslav Adzic, Nebojsa Marinkovic)....Pages 1-14 Electrocatalytic Reactions (Radoslav Adzic, Nebojsa Marinkovic)....Pages 15-18 Electrochemical Energy Conversion in Fuel Cells (Radoslav Adzic, Nebojsa Marinkovic)....Pages 19-25 Studies of Electrocatalytic Reactions (Radoslav Adzic, Nebojsa Marinkovic)....Pages 27-33 Important Electrosorption Reactions (Radoslav Adzic, Nebojsa Marinkovic)....Pages 35-55 Important Electrocatalytic Reactions (Radoslav Adzic, Nebojsa Marinkovic)....Pages 57-82 Platinum Monolayer Electrocatalysts (Radoslav Adzic, Nebojsa Marinkovic)....Pages 83-100 Catalytic Properties of Pt Monolayer Electrocatalysts (Radoslav Adzic, Nebojsa Marinkovic)....Pages 101-152 Performance Stability and Scale-Up Syntheses of Pt Monolayer Electrocatalysts (Radoslav Adzic, Nebojsa Marinkovic)....Pages 153-155 Palladium Monolayer Electrocatalysts (Radoslav Adzic, Nebojsa Marinkovic)....Pages 157-160 Prospects for Platinum and Platinum Group Metal Monolayer Electrocatalysts (Radoslav Adzic, Nebojsa Marinkovic)....Pages 161-162 Back Matter ....Pages 163-167