Handbook of Hydrogen Storage: New Materials for Future Energy Storage

Owing to the limited resources of fossil fuels, hydrogen is proposed as an alternative and environment-friendly energy carrier. However, its potential is limited by storage problems, especially for mobile applications. Current technologies, as compressed gas or liquefied hydrogen, comprise severe disadvantages and the storage of hydrogen in lightweight solids could be the solution to this problem. Since the optimal storage mechanism and optimal material have yet to be identified, this first handbook on the topic provides an excellent overview of the most probable candidates, highlighting both their advantages as well as drawbacks. From the contents: ¿ Physisorption ¿ Clathrates ¿ Metal hydrides ¿ Complex hydrides ¿ Amides, imides, and mixtures ¿ Tailoring Reaction Enthalpies ¿ Borazan ¿ Aluminum hydride ¿ Nanoparticles A one-stop reference on all questions concerning hydrogen storage for physical and solid state chemists, materials scientists, chemical engineers, and physicists.

Table of Contents:
Foreword v Preface xv List of Contributors xix 1 Storage of Hydrogen in the Pure Form 1 Manfred Klell 1.1 Introduction 1 1.2 Thermodynamic State and Properties 1 1.2.1 Variables of State 2 1.2.2 T–s-Diagram 4 1.2.2.1 Joule–Thomson Coefficient 5 1.2.3 Properties 5 1.3 Gaseous Storage 8 1.3.1 Compression and Expansion 10 1.3.2 Tank Systems 12 1.3.3 High Pressure Infrastructure 13 1.4 Liquid Storage 15 1.4.1 Liquefaction 15 1.4.2 Thermodynamic Analysis 17 1.4.2.1 Pressure Build-Up 21 1.4.2.2 Boil-Off 23 1.4.2.3 Cooling and Filling 24 1.4.2.4 Back-Gas 27 1.4.3 Tank Systems 28 1.4.4 Distribution Facilities 30 1.5 Hybrid Storage 30 1.5.1 Supercritical Storage 31 1.5.2 Hydrogen Slush 32 1.6 Comparison of Energy Densities 32 1.7 Conclusion 35 References 36 2 Physisorption in Porous Materials 39 Barbara Panella and Michael Hirscher 2.1 Introduction 39 2.2 Carbon Materials 44 2.3 Organic Polymers 48 2.4 Zeolites 50 2.5 Coordination Polymers 51 2.6 Conclusions 58 References 59 3 Clathrate Hydrates 63 Alireza Shariati, Sona Raeissi, and Cor J. Peters 3.1 Introduction 63 3.2 Clathrate Hydrate Structures 64 3.3 Hydrogen Clathrate Hydrate 66 3.4 Kinetic Aspects of Hydrogen Clathrate Hydrate 73 3.5 Modeling of Hydrogen Clathrate Hydrates 74 3.6 Future of Hydrogen Storage 76 References 77 4 Metal Hydrides 81 Jacques Huot 4.1 Introduction 81 4.2 Elemental Hydrides 82 4.2.1 Ionic or Saline Hydrides 82 4.2.2 Covalent Hydrides 82 4.2.3 Metallic Hydrides 83 4.3 Thermodynamics of Metal Hydrides 83 4.3.1 Introduction 83 4.3.2 Low Concentration 85 4.3.3 High Concentration 86 4.4 Intermetallic Compounds 88 4.4.1 Thermodynamics 88 4.4.1.1 Miedema.s Model 89 4.4.1.2 Semi-Empirical Band Structure Model 91 4.4.2 Crystal Structure 92 4.4.3 Electronic Structure 94 4.5 Practical Considerations 94 4.5.1 Synthesis 95 4.5.2 Activation 95 4.5.3 Hysteresis 96 4.5.4 Plateau Slope 97 4.5.5 Reversible Capacity 98 4.5.6 Hydrogenation Kinetics 98 4.5.7 Cycle Life 99 4.5.8 Decrepitation 99 4.6 Metal Hydrides Systems 100 4.6.1 AB5 100 4.6.2 TiFe 101 4.6.3 AB2 Laves Phases 102 4.6.4 BCC Solid Solution 103 4.7 Nanocrystalline Mg and Mg-Based Alloys 104 4.7.1 Hydrogen Sorption Kinetics 105 4.7.2 Reduction of the Heat of Formation 107 4.7.3 Severe Plastic Deformation Techniques 108 4.8 Conclusion 109 4.8.1 Alloys Development 109 4.8.2 Synthesis 110 4.8.3 System Engineering 110 References 110 5 Complex Hydrides 117 Claudia Weidenthaler and Michael Felderhoff 5.1 Introduction 117 5.2 Complex Borohydrides 118 5.2.1 Introduction 118 5.2.2 Stability of Metal Borohydrides 118 5.2.3 Decomposition of Complex Borohydrides 119 5.2.4 Lithium Borohydride, LiBH4 120 5.2.4.1 Synthesis and Crystal Structure 120 5.2.4.2 Decomposition of LiBH4 120 5.2.5 Sodium Borohydride, NaBH4 122 5.2.5.1 Synthesis and Crystal Structure 122 5.2.5.2 Decomposition of NaBH4 122 5.2.6 Potassium Borohydride KBH4 122 5.2.7 Beryllium Borohydride Be(BH4)2 123 5.2.8 Magnesium Borohydride Mg(BH4)2 123 5.2.8.1 Synthesis and Crystal Structure 123 5.2.8.2 Decomposition 123 5.2.9 Calcium Borohydride Ca(BH4)2 124 5.2.9.1 Synthesis and Crystal Structure 124 5.2.9.2 Decomposition 125 5.2.10 Aluminum Borohydride Al(BH4)3 126 5.2.10.1 Synthesis and Crystal Structure 126 5.2.10.2 Decomposition 126 5.2.11 Zinc Borohydride Zn(BH4)2 126 5.2.12 NaBH4 as a Hydrogen Storage Material in Solution 126 5.2.12.1 Regeneration of Decomposed NaBH4 in Solution 128 5.3 Complex Aluminum Hydrides 128 5.3.1 Introduction 128 5.3.2 LiAlH4 130 5.3.2.1 Synthesis and Crystal Structure 130 5.3.2.2 Decomposition of LiAlH4 130 5.3.2.3 Role of Catalysts 131 5.3.3 Li3AlH6 132 5.3.3.1 Synthesis and Crystal Structure 132 5.3.4 NaAlH4 133 5.3.4.1 Synthesis and Crystal Structure 133 5.3.4.2 Decomposition and Thermodynamics of NaAlH4 133 5.3.4.3 Role of Catalysts 135 5.3.5 Na3AlH6 138 5.3.5.1 Synthesis and Crystal Structure 138 5.3.6 KAlH4 139 5.3.6.1 Synthesis and Crystal Structure 139 5.3.6.2 Decomposition of KAlH4 140 5.3.7 Mg(AlH4)2 140 5.3.7.1 Synthesis and Crystal Structure 140 5.3.7.2 Decompositon 141 5.3.8 Ca(AlH4)2 142 5.3.8.1 Synthesis and Crystal Structure 142 5.3.8.2 Decomposition of Ca(AlH4)2 143 5.3.9 Na2LiAlH6 144 5.3.10 K2LiAlH6 145 5.3.11 K2NaAlH6 145 5.3.12 LiMg(AlH4)3, LiMgAlH6 146 5.3.12.1 Synthesis and Crystal Structure 146 5.3.12.2 Decomposition 146 5.3.13 Sr2AlH7 146 5.3.14 BaAlH5 147 5.3.14.1 Synthesis and Crystal Structure 147 5.4 Complex Transition Metal Hydrides 148 5.4.1 Introduction 148 5.4.2 Properties 148 5.4.3 Synthesis 149 5.4.4 Examples of Complex Transition Metal Hydrides 150 5.5 Summary 150 References 151 6 Amides, Imides and Mixtures 159 Takayuki Ichikawa 6.1 Introduction 159 6.2 Hydrogen Storage Properties of Amide and Imide Systems 160 6.2.1 Li–N–H System 160 6.2.2 Li–Mg–N-H Systems 161 6.2.3 Other Metal–N–H Systems 165 6.3 Structural Properties of Amide and Imide 167 6.3.1 Lithium Amide and Imide 168 6.3.2 Sodium Amide 171 6.3.3 Magnesium Amide and Imide 171 6.3.4 Other Amides and Imides 172 6.4 Prospects of Amide and Imide Systems 173 6.4.1 Kinetic Analysis and Improvement 173 6.4.2 NH3 Amount Desorbed from Metal–N–H Systems 176 6.4.3 Practical Properties 177 6.5 Proposed Mechanism of the Hydrogen Storage Reaction in the Metal–N–H Systems 178 6.5.1 Ammonia-Mediated Model for Hydrogen Desorption 178 6.5.2 Direct Solid–Solid Reaction Model for Hydrogen Desorption 180 6.5.3 Hydrogenating Mechanism of the Li-Mg-N-H System 181 6.6 Summary 182 References 182 7 Tailoring Reaction Enthalpies of Hydrides 187 Martin Dornheim 7.1 Introduction 187 7.2 Thermodynamic Limitations of Lightweight Hydrides 189 7.3 Strategies to Alter the Reaction Enthalpies of Hydrides 191 7.3.1 Thermodynamic Tuning of Single Phase Hydrides by Substitution on the Metal Site 191 7.3.1.1 Lightweight Hydrides Forming Stable Compounds in the Dehydrogenated State 193 7.3.1.2 Lightweight Hydrides with Positive Heat of Mixing in the Dehydrogenated State 196 7.3.2 Thermodynamic Tuning of Single Phase Hydrides by Substitution on the Hydrogen Sites: Functional Anion Concept 199 7.3.3 Multicomponent Hydride Systems 203 7.3.3.1 Mixtures of Hydrides and Reactive Additives 203 7.3.3.2 Mixed Hydrides/Reactive Hydride Composites 207 7.4 Summary and Conclusion 210 References 211 8 Ammonia Borane and Related Compounds as Hydrogen Source Materials 215 Florian Mertens, Gert Wolf, and Felix Baitalow 8.1 Introduction 215 8.2 Materials Description and Characterization 216 8.3 Production 219 8.4 Thermally Induced Decomposition of Pure Ammonia Borane 221 8.4.1 Pyrolysis 221 8.4.2 Decomposition in Organic Solvents 227 8.4.3 Decomposition of Ammonia Borane in Heterogeneous Systems 232 8.5 Hydrolysis of AB 233 8.6 Substituted Ammonia Boranes 235 8.7 Recycling Strategies 238 8.7.1 Recycling from B-O-Containing Materials 239 8.7.2 Recycling of BNHx-Waste Products 240 8.8 Summary 243 References 244 9 Aluminum Hydride (Alane) 249 Ragaiy Zidan 249 9.1 Introduction 249 9.2 Hydrogen Solubility and Diffusivity in Aluminum 250 9.3 Formation and Thermodynamics of Different Phases of Alane 252 9.4 Stability and Formation of Adduct Organo-Aluminum Hydride Compounds 260 9.5 Phases and Structures of Aluminum Hydride 266 9.6 Novel Attempts and Methods for Forming Alane Reversibly 269 9.7 Conclusion 275 References 275 10 Nanoparticles and 3D Supported Nanomaterials 279 Petra E. de Jongh and Philipp Adelhelm 10.1 Introduction 279 10.2 Particle Size Effects 281 10.2.1 Thermodynamics 281 10.2.2 Kinetics 287 10.3 Non-Supported Clusters, Particles and Nanostructures 290 10.3.1 Transition Metal Clusters 291 10.3.2 Interstitial Hydrides, Focussing on Palladium Hydride 293 10.3.3 Ionic Hydrides, Focussing on Magnesium Hydride 296 10.4 Support Effects 301 10.4.1 Stabilization of Small Particle Sizes 302 10.4.2 Limiting Phase Segregation in Complex Systems 303 10.4.3 Metal–Substrate Interaction 305 10.4.4 Physical Confinement and Clamping 307 10.4.5 Thermal Properties of the System 309 10.4.6 Mechanical Stability and Pressure Drop 309 10.5 Preparation of Three-Dimensional Supported Nanomaterials 311 10.5.1 Support Materials 311 10.5.1.1 Silica 312 10.5.1.2 Carbon 314 10.5.1.3 Other Support Materials 316 10.5.2 Preparation Strategies 317 10.5.2.1 Solution Impregnation 318 10.5.2.2 Melt Infiltration 320 10.6 Experimental Results on 3D-Supported Nanomaterials 322 10.6.1 Ammonia Borane, (NH3BH3) 323 10.6.2 Sodium Alanate, (NaAlH4) 325 10.6.3 Magnesium Hydride (MgH2) 329 10.6.4 Lithium Borohydride (LiBH4) 331 10.6.5 Palladium 333 10.7 Conclusions and Outlook 334 References 336 Index 341