Yann Garcia is Professor of Analytical Chemistry at UCLouvain, IBAME vice-chair and GFSM president.Junhu Wang is Professor & Group Leader at Dalian Institute of Chemical Physics, Chinese Academy of Sciences and Secretary General of Mössbauer Effect Data Center.Tao Zhang is Vice President at the Chinese Academy of Sciences and Director of Mössbauer Effect Data Center.

• Preface xi1 Application of Mössbauer Spectroscopy to Energy Materials 1Pierre-Emmanuel Lippens, Jean-Claude Jumas, and Josette Olivier-Fourcade1.1 Introduction 11.2 Mössbauer Spectroscopy for Li-ion and Na-ion Batteries 21.2.1 Characterization of Electrode Materials and Electrochemical Reactions 21.2.2 Tin-Based Negative Electrode Materials for Li-ion Batteries 31.2.2.1 Electrochemical Reactions of Lithium with Tin 31.2.2.2 Tin Oxides 71.2.2.3 Tin Borophosphates 101.2.2.4 Tin-Based Intermetallics 131.2.3 Iron-Based Electrode Materials 171.2.3.1 LiFePO4 as Positive Electrode Material for Li-ion Batteries 171.2.3.2 Fe 1.19 PO4 (OH) 0.57 (H2 O) 0.43 /C as Positive Electrode Material for Li-ion Batteries 181.2.3.3 Na 1.5 Fe 0.5 Ti 1.5 (PO4) 3 /C as Electrode Material for Na-ion Batteries 191.3 Mössbauer Spectroscopy of Tin-Based Catalysts 211.3.1 Reforming Catalysis 211.3.2 Redox Properties of Pt-Sn Based Catalysts 221.3.3 Trimetallic Pt-Sn-In Based Catalysts 241.4 Conclusion 26Acknowledgments 27References 272 Mössbauer Spectral Studies of Iron Phosphate Containing Minerals and Compounds 33Gary J. Long and Fernande Grandjean2.1 Introduction 332.2 Thermodynamic Properties of Iron Phosphate Containing Compounds 342.3 Room Temperature Mössbauer Spectra of Iron Phosphate Containing Minerals 372.4 Analysis of Magnetically Ordered Mössbauer Spectra 502.5 Structural and Thermodynamic Properties of the Polymorphs of FePO4 532.5.1 Polymorphs of FePO4 532.6 Mössbauer Spectra of α-FePO4 552.7 Magnetic Structure of α-FePO4 , Obtained by Mössbauer Spectroscopy 572.7.1 Magnetic Structure of α-FePO4 572.8 Temperature Dependence of the α-FePO4 Structure Tilt Angle 602.9 Mössbauer Spectral Studies on Metastable Polymorphs of FePO4 622.9.1 Crystallographic Structures of Two Polymorphs of FePO4 ⋅2H2 O 622.9.2 Preparation and Crystallographic Structures of the Two Polymorphs, γ-FePO4 and ζ-FePO4 622.9.3 Mössbauer Spectral Studies of FePO4 Metastable Polymorphs 642.9.4 Preparation and Mössbauer Spectra of Synthetic Heterosite, (Fe,Mn)PO4 672.9.5 Fits of the Magnetic Mössbauer Spectra of η-Fe 0.9 Mn 0.1 PO4 682.10 Mössbauer Spectral Studies of Various Iron Phosphate Compounds 732.10.1 Mössbauer Spectral Properties of α-Fe2 (PO4)O 742.10.2 Mössbauer Spectral Properties of Fe3 (PO4)O3 792.10.3 Preparation and Structural Properties of Fe9 (PO4)O8 802.10.4 Mössbauer Spectral Properties of Fe9 (PO4)O8 81Acknowledgments 85References and Notes 853 Mössbauer Spectroscopic Investigation of Fe-Based Silicides 93Xiao Chen, Junhu Wang, and Changhai Liang3.1 Introduction 933.2 Mössbauer Spectroscopic Investigation of Iron Silicides Prepared By Mechanical Alloying and Heat Treatment 953.3 Mössbauer Spectra of Iron Silicide on Silica Prepared by Pyrolysis of Ferrocene-Polydimethylsilane Composites 993.4 Synthesis and Mössbauer Spectra of Iron Silicides by Temperature-Programmed Silicification 1023.5 Mössbauer Spectroscopic Investigation of Doped Iron Silicides 1043.6 Conclusion and Perspective 107References 1084 Mössbauer Spectroscopy of Catalysts 113Károly Lázár4.1 Introduction 1134.2 Principles of the Mössbauer Effect and Outlook of Its Application for Catalyst Studies 1164.2.1 Brief Overview of the Basics of Mössbauer Spectroscopy 1164.2.2 Mössbauer Spectroscopy from the Point of View of Catalyst Studies – Particular Features 1174.2.3 The Probability of the Mössbauer Effect – f-Factor and Size Effects 1184.2.4 Variants of the Technique 1204.2.4.1 57Co Emission Spectroscopy 1204.2.4.2 Synchrotron-Based NFS (Nuclear Forward Scattering) 1224.2.4.3 Conversion Electron Mössbauer Spectroscopy 1224.2.5 Technical Implementations – Experimental Conditions 1234.3 Heterogeneous Catalysts 1244.3.1 Sites on Supported Particles with Different Participation in Catalytic Processes 1244.3.2 Collective Effects in Particles (Magnetism) 1254.3.3 Case Studies 1264.3.3.1 Metals and Alloys 1264.3.3.2 Oxide Catalysts 1304.3.3.3 Catalysts with Fe–N, Fe–C, and Fe–N–C Centers 1334.4 Biocatalysts – Enzymes 1354.5 Homogeneous Catalysts – Frozen Solutions 1354.5.1 Studies on Reaction Intermediates – Time-Resolved Freeze-Quenched Spectra 1364.6 Conclusions 137Acknowledgment 137References 1385 Application of Mössbauer Spectroscopy in Studying Catalysts for CO Oxidation and Preferential Oxidation of CO in H2145Kuo Liu, Junhu Wang, and Tao Zhang5.1 Introduction 1455.2 Application of Mössbauer Spectroscopy in CO Oxidation 1475.2.1 57 Fe Mössbauer Spectroscopy 1475.2.2 119 Sn Mössbauer Spectroscopy 1505.2.3 197 Au Mössbauer Spectroscopy 1515.2.4 193 Ir Mössbauer spectroscopy 1525.3 Application of Mössbauer Spectroscopy in PROX 1535.3.1 PtFe-Containing Catalysts 1535.3.2 Au-Based Catalysts 1555.3.3 IrFe-Containing Catalysts 1585.3.3.1 Porous Carbon Supported IrFe Catalysts 1585.3.3.2 SiO2 and Al2 O3 Supported IrFe Catalysts 1595.3.4 CuO/CeO2 with Fe2 O3 Additive 1655.4 Concluding Remarks 165Acknowledgments 166References 1666 Application of 57 Fe Mössbauer Spectroscopy in Studying Fe–N–C Catalysts for Oxygen Reduction Reaction in Proton Exchange Membrane Fuel Cells 171Xinlong Xu, Junhu Wang, Suli Wang, and Gongquan Sun6.1 Introduction 1716.2 Advanced 57Fe Mössbauer Spectroscopy Technique 1736.2.1 Room Temperature 57Fe Mössbauer Spectroscopy 1736.2.2 Low Temperature and Computational 57Fe Mössbauer Spectroscopy 1746.2.3 In Situ Electrochemical 57Fe Mössbauer Spectroscopy 1756.3 Characterization of Fe–N–C Using 57Fe Mössbauer Spectroscopy 1776.3.1 Identification of Active Sites 1776.3.2 Investigation of Degradation Mechanism 1806.3.3 Optimization for Synthesis of Fe–N–C 1846.3.3.1 Precursor Composition 1846.3.3.2 Heat Treatment 1856.4 Summary and Perspective 187Acknowledgments 188References 1887 197 Au Mössbauer Spectroscopy of Thiolate-protected Gold Clusters 195Norimichi Kojima, Yasuhiro Kobaqyashi, and Makoto Seto7.1 Introduction 1957.2 Synthesis of Thiolate Protected Gold Clusters 1977.3 197 Au Mössbauer Spectroscopy of Gold Nano-clusters 1987.3.1 Experimental Procedure of 197 Au Mössbauer Spectroscopy 1987.3.2 197 Au Mössbauer Spectra of Aun (SG)m(n = 10∼55) 1987.3.3 Molecular Structure and 197 Au Mössbauer Spectra of Au10 (SG)10 1987.3.4 Molecular Structure and 197 Au Mössbauer Spectra of Au25 (SG)18 2007.3.5 Structural Evolution of Aun (SG)m(n = 10∼55) Based on 197 Au Mössbauer Spectroscopy 2017.3.6 197 Au Mössbauer Spectra of Au24 Pd1 (SC12 H25)18 2047.3.7 197 Au Mössbauer Spectra of Aun (SC12 H25)m 2057.4 Conclusion 208Acknowledgments 208References 2098 197 Au Mössbauer Spectroscopy of Gold Mixed-Valence Complexes, Cs2 [AuI X2 ][AuIII Y4 ](X, Y = Cl, Br, I) and [NH3 (CH2)n NH3 ]2[(AuI I2)(AuIII I4)(I3)2](n= 7, 8) 213Norimichi Kojima, Yasuhiro Kobaqyashi, and Makoto Seto8.1 Introduction 2138.2 Experimental Procedure 2168.2.1 Synthesis and Characterization 2168.2.1.1 Cs2 [AuI X2][AuIII Y4 ](X,Y= Cl, Br, I) 2168.2.1.2 [NH3 (CH2)n NH3 ]2 [(AuI I2)(AuIII I4)(I3)2 ](n= 7, 8) 2178.2.2 197 Au Mössbauer Spectroscopy 2178.3 Crystal Structure of Cs2 [AuI X2][ AuIII X4](X,Y= Cl, Br, I) 2188.4 Chemical Bond of Au−Xin[AuI X2] − and [AuIII X4] − 2218.5 Mössbauer Parameters of 197 Au in [AuI X2] − and [AuIII X4 ] − 2238.5.1 Mössbauer Parameters of 197 Au in (C4 H9)4 N[AuI X2] and (C4 H9)4 N[AuIII Y4] 2248.5.1.1 Isomer Shift 2248.5.1.2 Quadrupole Splitting 2248.5.2 Mössbauer Parameters of 197 Au in Cs2 [AuI X2] [ AuIII Y4] (X = Cl, Br, I) 2258.5.2.1 Isomer Shift 2258.5.2.2 Quadrupole Splitting 2268.5.2.3 Analysis of 197 Au Mössbauer Parameters for Cs2 [AuI X2] [ AuIII Y4] 2268.6 Charge Transfer Interaction in Cs2 [AuI X2] [ AuIII Y4](X= Cl, Br, I) 2278.7 197 Au Mössbauer Spectra of Cs2 [AuI X2] [ AuIII Y4](X,Y= Cl, Br, I) 2288.7.1 Isomer Shift of AuI in Cs2 [AuI X2] [ AuIII Y4] 2288.7.2 Isomer Shift of AuIII in Cs2 [AuI X2] [ AuIII Y4] 2308.7.3 Quadrupole Splitting of AuI in Cs2 [AuI X2 ] [AuIII Y4 ] 2308.7.4 Quadrupole Splitting of AuIII in Cs2 [AuI X2] [AuIII Y4 ] 2318.8 Single Crystal 197 Au Mössbauer Spectra of Cs2 [AuI I2 ] [AuIII I4 ] 2318.8.1 Comparison of 197 Au Mössbauer Spectra Between Single Crystal and Powder Crystal 2318.8.2 Sign of EFG for AuI in [AuI I2 ] − and AuIII in [AuIII X4 ] − 2348.9 197 Au Mössbauer Spectra of Cs2 [AuI X 2 ] [AuIII X4 ](X= Cl, I) Under High Pressures 2358.9.1 Phase Diagram of Cs2 [AuI X2 ] [AuIII X4 ](X= Cl, Br, I) 2358.9.2 Origin of Metallic Mixed-Valence State in Cs2 [AuI Cl2 ] [AuIII Cl4 ] 2368.9.3 Au Valence Transition in Cs2 [Au II2 ] [AuIII I4 ] 2398.10 197 Au Mössbauer Spectra of [NH3 (CH2)n NH3 ]2 [(Au II2)(AuIII I4)(I3)2 ] (n = 7, 8) 2418.11 Conclusion 243Acknowledgments 244  References 2459 Temperature- and Photo-Induced Spin-Crossover in Molecule-Based Magnets 251Hiroko Tokoro, Kenta Imoto, and Shin-ichi Ohkoshi9.1 Introduction 2519.2 Spin-Crossover Phenomena in Cesium Iron Hexacyanidochromate Prussian Blue Analog 2529.3 Light-Induced Spin-Crossover Magnet in Iron Octacyanidoniobate Bimetal Assembly 2549.4 Chiral Photomagnetism and Light-Controllable Second Harmonic Light in Iron Octacyanidoniobate Bimetal Assembly 2589.5 Conclusion and Perspective 265References 26510 Developing a Methodology to Obtain New Photoswitchable Fe(II) Spin Crossover Complexes 271Varun Kumar and Yann Garcia10.1 Introduction and Context 27110.2 Introduction to a New Photo-responsive Anion: psca 27510.3 Combining Fe(II) and psca Together in a Single Compound 27610.4 Fe(II) Mononuclear Complexes with DMPP and psca Ligands 27810.5 1D Fe(II) Coordination Polymer with psca as Non-Coordinated Anions 28110.6 Conclusions and Perspectives 284References 28511 57 Fe Mössbauer Spectroscopy as a Prime Tool to Explore a New Family of Colorimetric Sensors 291li Sun, Weiyang li, and Yann Garcia11.1 Introduction and General Context 29111.2 Colorimetric Gas Sensors Based on Fe(II) Complexes 29211.3 Conclusions and Perspectives 306References 306Index 311

Yann Garcia is Professor of Analytical Chemistry at UCLouvain, IBAME vice-chair and GFSM president.Junhu Wang is Professor & Group Leader at Dalian Institute of Chemical Physics, Chinese Academy of Sciences and Secretary General of Mössbauer Effect Data Center.Tao Zhang is Vice President at the Chinese Academy of Sciences and Director of Mössbauer Effect Data Center.

• Preface xi1 Application of Mössbauer Spectroscopy to Energy Materials 1Pierre-Emmanuel Lippens, Jean-Claude Jumas, and Josette Olivier-Fourcade1.1 Introduction 11.2 Mössbauer Spectroscopy for Li-ion and Na-ion Batteries 21.2.1 Characterization of Electrode Materials and Electrochemical Reactions 21.2.2 Tin-Based Negative Electrode Materials for Li-ion Batteries 31.2.2.1 Electrochemical Reactions of Lithium with Tin 31.2.2.2 Tin Oxides 71.2.2.3 Tin Borophosphates 101.2.2.4 Tin-Based Intermetallics 131.2.3 Iron-Based Electrode Materials 171.2.3.1 LiFePO4 as Positive Electrode Material for Li-ion Batteries 171.2.3.2 Fe 1.19 PO4 (OH) 0.57 (H2 O) 0.43 /C as Positive Electrode Material for Li-ion Batteries 181.2.3.3 Na 1.5 Fe 0.5 Ti 1.5 (PO4) 3 /C as Electrode Material for Na-ion Batteries 191.3 Mössbauer Spectroscopy of Tin-Based Catalysts 211.3.1 Reforming Catalysis 211.3.2 Redox Properties of Pt-Sn Based Catalysts 221.3.3 Trimetallic Pt-Sn-In Based Catalysts 241.4 Conclusion 26Acknowledgments 27References 272 Mössbauer Spectral Studies of Iron Phosphate Containing Minerals and Compounds 33Gary J. Long and Fernande Grandjean2.1 Introduction 332.2 Thermodynamic Properties of Iron Phosphate Containing Compounds 342.3 Room Temperature Mössbauer Spectra of Iron Phosphate Containing Minerals 372.4 Analysis of Magnetically Ordered Mössbauer Spectra 502.5 Structural and Thermodynamic Properties of the Polymorphs of FePO4 532.5.1 Polymorphs of FePO4 532.6 Mössbauer Spectra of α-FePO4 552.7 Magnetic Structure of α-FePO4 , Obtained by Mössbauer Spectroscopy 572.7.1 Magnetic Structure of α-FePO4 572.8 Temperature Dependence of the α-FePO4 Structure Tilt Angle 602.9 Mössbauer Spectral Studies on Metastable Polymorphs of FePO4 622.9.1 Crystallographic Structures of Two Polymorphs of FePO4 ⋅2H2 O 622.9.2 Preparation and Crystallographic Structures of the Two Polymorphs, γ-FePO4 and ζ-FePO4 622.9.3 Mössbauer Spectral Studies of FePO4 Metastable Polymorphs 642.9.4 Preparation and Mössbauer Spectra of Synthetic Heterosite, (Fe,Mn)PO4 672.9.5 Fits of the Magnetic Mössbauer Spectra of η-Fe 0.9 Mn 0.1 PO4 682.10 Mössbauer Spectral Studies of Various Iron Phosphate Compounds 732.10.1 Mössbauer Spectral Properties of α-Fe2 (PO4)O 742.10.2 Mössbauer Spectral Properties of Fe3 (PO4)O3 792.10.3 Preparation and Structural Properties of Fe9 (PO4)O8 802.10.4 Mössbauer Spectral Properties of Fe9 (PO4)O8 81Acknowledgments 85References and Notes 853 Mössbauer Spectroscopic Investigation of Fe-Based Silicides 93Xiao Chen, Junhu Wang, and Changhai Liang3.1 Introduction 933.2 Mössbauer Spectroscopic Investigation of Iron Silicides Prepared By Mechanical Alloying and Heat Treatment 953.3 Mössbauer Spectra of Iron Silicide on Silica Prepared by Pyrolysis of Ferrocene-Polydimethylsilane Composites 993.4 Synthesis and Mössbauer Spectra of Iron Silicides by Temperature-Programmed Silicification 1023.5 Mössbauer Spectroscopic Investigation of Doped Iron Silicides 1043.6 Conclusion and Perspective 107References 1084 Mössbauer Spectroscopy of Catalysts 113Károly Lázár4.1 Introduction 1134.2 Principles of the Mössbauer Effect and Outlook of Its Application for Catalyst Studies 1164.2.1 Brief Overview of the Basics of Mössbauer Spectroscopy 1164.2.2 Mössbauer Spectroscopy from the Point of View of Catalyst Studies – Particular Features 1174.2.3 The Probability of the Mössbauer Effect – f-Factor and Size Effects 1184.2.4 Variants of the Technique 1204.2.4.1 57Co Emission Spectroscopy 1204.2.4.2 Synchrotron-Based NFS (Nuclear Forward Scattering) 1224.2.4.3 Conversion Electron Mössbauer Spectroscopy 1224.2.5 Technical Implementations – Experimental Conditions 1234.3 Heterogeneous Catalysts 1244.3.1 Sites on Supported Particles with Different Participation in Catalytic Processes 1244.3.2 Collective Effects in Particles (Magnetism) 1254.3.3 Case Studies 1264.3.3.1 Metals and Alloys 1264.3.3.2 Oxide Catalysts 1304.3.3.3 Catalysts with Fe–N, Fe–C, and Fe–N–C Centers 1334.4 Biocatalysts – Enzymes 1354.5 Homogeneous Catalysts – Frozen Solutions 1354.5.1 Studies on Reaction Intermediates – Time-Resolved Freeze-Quenched Spectra 1364.6 Conclusions 137Acknowledgment 137References 1385 Application of Mössbauer Spectroscopy in Studying Catalysts for CO Oxidation and Preferential Oxidation of CO in H2145Kuo Liu, Junhu Wang, and Tao Zhang5.1 Introduction 1455.2 Application of Mössbauer Spectroscopy in CO Oxidation 1475.2.1 57 Fe Mössbauer Spectroscopy 1475.2.2 119 Sn Mössbauer Spectroscopy 1505.2.3 197 Au Mössbauer Spectroscopy 1515.2.4 193 Ir Mössbauer spectroscopy 1525.3 Application of Mössbauer Spectroscopy in PROX 1535.3.1 PtFe-Containing Catalysts 1535.3.2 Au-Based Catalysts 1555.3.3 IrFe-Containing Catalysts 1585.3.3.1 Porous Carbon Supported IrFe Catalysts 1585.3.3.2 SiO2 and Al2 O3 Supported IrFe Catalysts 1595.3.4 CuO/CeO2 with Fe2 O3 Additive 1655.4 Concluding Remarks 165Acknowledgments 166References 1666 Application of 57 Fe Mössbauer Spectroscopy in Studying Fe–N–C Catalysts for Oxygen Reduction Reaction in Proton Exchange Membrane Fuel Cells 171Xinlong Xu, Junhu Wang, Suli Wang, and Gongquan Sun6.1 Introduction 1716.2 Advanced 57Fe Mössbauer Spectroscopy Technique 1736.2.1 Room Temperature 57Fe Mössbauer Spectroscopy 1736.2.2 Low Temperature and Computational 57Fe Mössbauer Spectroscopy 1746.2.3 In Situ Electrochemical 57Fe Mössbauer Spectroscopy 1756.3 Characterization of Fe–N–C Using 57Fe Mössbauer Spectroscopy 1776.3.1 Identification of Active Sites 1776.3.2 Investigation of Degradation Mechanism 1806.3.3 Optimization for Synthesis of Fe–N–C 1846.3.3.1 Precursor Composition 1846.3.3.2 Heat Treatment 1856.4 Summary and Perspective 187Acknowledgments 188References 1887 197 Au Mössbauer Spectroscopy of Thiolate-protected Gold Clusters 195Norimichi Kojima, Yasuhiro Kobaqyashi, and Makoto Seto7.1 Introduction 1957.2 Synthesis of Thiolate Protected Gold Clusters 1977.3 197 Au Mössbauer Spectroscopy of Gold Nano-clusters 1987.3.1 Experimental Procedure of 197 Au Mössbauer Spectroscopy 1987.3.2 197 Au Mössbauer Spectra of Aun (SG)m(n = 10∼55) 1987.3.3 Molecular Structure and 197 Au Mössbauer Spectra of Au10 (SG)10 1987.3.4 Molecular Structure and 197 Au Mössbauer Spectra of Au25 (SG)18 2007.3.5 Structural Evolution of Aun (SG)m(n = 10∼55) Based on 197 Au Mössbauer Spectroscopy 2017.3.6 197 Au Mössbauer Spectra of Au24 Pd1 (SC12 H25)18 2047.3.7 197 Au Mössbauer Spectra of Aun (SC12 H25)m 2057.4 Conclusion 208Acknowledgments 208References 2098 197 Au Mössbauer Spectroscopy of Gold Mixed-Valence Complexes, Cs2 [AuI X2 ][AuIII Y4 ](X, Y = Cl, Br, I) and [NH3 (CH2)n NH3 ]2[(AuI I2)(AuIII I4)(I3)2](n= 7, 8) 213Norimichi Kojima, Yasuhiro Kobaqyashi, and Makoto Seto8.1 Introduction 2138.2 Experimental Procedure 2168.2.1 Synthesis and Characterization 2168.2.1.1 Cs2 [AuI X2][AuIII Y4 ](X,Y= Cl, Br, I) 2168.2.1.2 [NH3 (CH2)n NH3 ]2 [(AuI I2)(AuIII I4)(I3)2 ](n= 7, 8) 2178.2.2 197 Au Mössbauer Spectroscopy 2178.3 Crystal Structure of Cs2 [AuI X2][ AuIII X4](X,Y= Cl, Br, I) 2188.4 Chemical Bond of Au−Xin[AuI X2] − and [AuIII X4] − 2218.5 Mössbauer Parameters of 197 Au in [AuI X2] − and [AuIII X4 ] − 2238.5.1 Mössbauer Parameters of 197 Au in (C4 H9)4 N[AuI X2] and (C4 H9)4 N[AuIII Y4] 2248.5.1.1 Isomer Shift 2248.5.1.2 Quadrupole Splitting 2248.5.2 Mössbauer Parameters of 197 Au in Cs2 [AuI X2] [ AuIII Y4] (X = Cl, Br, I) 2258.5.2.1 Isomer Shift 2258.5.2.2 Quadrupole Splitting 2268.5.2.3 Analysis of 197 Au Mössbauer Parameters for Cs2 [AuI X2] [ AuIII Y4] 2268.6 Charge Transfer Interaction in Cs2 [AuI X2] [ AuIII Y4](X= Cl, Br, I) 2278.7 197 Au Mössbauer Spectra of Cs2 [AuI X2] [ AuIII Y4](X,Y= Cl, Br, I) 2288.7.1 Isomer Shift of AuI in Cs2 [AuI X2] [ AuIII Y4] 2288.7.2 Isomer Shift of AuIII in Cs2 [AuI X2] [ AuIII Y4] 2308.7.3 Quadrupole Splitting of AuI in Cs2 [AuI X2 ] [AuIII Y4 ] 2308.7.4 Quadrupole Splitting of AuIII in Cs2 [AuI X2] [AuIII Y4 ] 2318.8 Single Crystal 197 Au Mössbauer Spectra of Cs2 [AuI I2 ] [AuIII I4 ] 2318.8.1 Comparison of 197 Au Mössbauer Spectra Between Single Crystal and Powder Crystal 2318.8.2 Sign of EFG for AuI in [AuI I2 ] − and AuIII in [AuIII X4 ] − 2348.9 197 Au Mössbauer Spectra of Cs2 [AuI X 2 ] [AuIII X4 ](X= Cl, I) Under High Pressures 2358.9.1 Phase Diagram of Cs2 [AuI X2 ] [AuIII X4 ](X= Cl, Br, I) 2358.9.2 Origin of Metallic Mixed-Valence State in Cs2 [AuI Cl2 ] [AuIII Cl4 ] 2368.9.3 Au Valence Transition in Cs2 [Au II2 ] [AuIII I4 ] 2398.10 197 Au Mössbauer Spectra of [NH3 (CH2)n NH3 ]2 [(Au II2)(AuIII I4)(I3)2 ] (n = 7, 8) 2418.11 Conclusion 243Acknowledgments 244  References 2459 Temperature- and Photo-Induced Spin-Crossover in Molecule-Based Magnets 251Hiroko Tokoro, Kenta Imoto, and Shin-ichi Ohkoshi9.1 Introduction 2519.2 Spin-Crossover Phenomena in Cesium Iron Hexacyanidochromate Prussian Blue Analog 2529.3 Light-Induced Spin-Crossover Magnet in Iron Octacyanidoniobate Bimetal Assembly 2549.4 Chiral Photomagnetism and Light-Controllable Second Harmonic Light in Iron Octacyanidoniobate Bimetal Assembly 2589.5 Conclusion and Perspective 265References 26510 Developing a Methodology to Obtain New Photoswitchable Fe(II) Spin Crossover Complexes 271Varun Kumar and Yann Garcia10.1 Introduction and Context 27110.2 Introduction to a New Photo-responsive Anion: psca 27510.3 Combining Fe(II) and psca Together in a Single Compound 27610.4 Fe(II) Mononuclear Complexes with DMPP and psca Ligands 27810.5 1D Fe(II) Coordination Polymer with psca as Non-Coordinated Anions 28110.6 Conclusions and Perspectives 284References 28511 57 Fe Mössbauer Spectroscopy as a Prime Tool to Explore a New Family of Colorimetric Sensors 291li Sun, Weiyang li, and Yann Garcia11.1 Introduction and General Context 29111.2 Colorimetric Gas Sensors Based on Fe(II) Complexes 29211.3 Conclusions and Perspectives 306References 306Index 311

Yann Garcia is Professor of Analytical Chemistry at UCLouvain, IBAME vice-chair and GFSM president.Junhu Wang is Professor & Group Leader at Dalian Institute of Chemical Physics, Chinese Academy of Sciences and Secretary General of Mössbauer Effect Data Center.Tao Zhang is Vice President at the Chinese Academy of Sciences and Director of Mössbauer Effect Data Center.

• Preface xi1 Application of Mössbauer Spectroscopy to Energy Materials 1Pierre-Emmanuel Lippens, Jean-Claude Jumas, and Josette Olivier-Fourcade1.1 Introduction 11.2 Mössbauer Spectroscopy for Li-ion and Na-ion Batteries 21.2.1 Characterization of Electrode Materials and Electrochemical Reactions 21.2.2 Tin-Based Negative Electrode Materials for Li-ion Batteries 31.2.2.1 Electrochemical Reactions of Lithium with Tin 31.2.2.2 Tin Oxides 71.2.2.3 Tin Borophosphates 101.2.2.4 Tin-Based Intermetallics 131.2.3 Iron-Based Electrode Materials 171.2.3.1 LiFePO4 as Positive Electrode Material for Li-ion Batteries 171.2.3.2 Fe 1.19 PO4 (OH) 0.57 (H2 O) 0.43 /C as Positive Electrode Material for Li-ion Batteries 181.2.3.3 Na 1.5 Fe 0.5 Ti 1.5 (PO4) 3 /C as Electrode Material for Na-ion Batteries 191.3 Mössbauer Spectroscopy of Tin-Based Catalysts 211.3.1 Reforming Catalysis 211.3.2 Redox Properties of Pt-Sn Based Catalysts 221.3.3 Trimetallic Pt-Sn-In Based Catalysts 241.4 Conclusion 26Acknowledgments 27References 272 Mössbauer Spectral Studies of Iron Phosphate Containing Minerals and Compounds 33Gary J. Long and Fernande Grandjean2.1 Introduction 332.2 Thermodynamic Properties of Iron Phosphate Containing Compounds 342.3 Room Temperature Mössbauer Spectra of Iron Phosphate Containing Minerals 372.4 Analysis of Magnetically Ordered Mössbauer Spectra 502.5 Structural and Thermodynamic Properties of the Polymorphs of FePO4 532.5.1 Polymorphs of FePO4 532.6 Mössbauer Spectra of α-FePO4 552.7 Magnetic Structure of α-FePO4 , Obtained by Mössbauer Spectroscopy 572.7.1 Magnetic Structure of α-FePO4 572.8 Temperature Dependence of the α-FePO4 Structure Tilt Angle 602.9 Mössbauer Spectral Studies on Metastable Polymorphs of FePO4 622.9.1 Crystallographic Structures of Two Polymorphs of FePO4 ⋅2H2 O 622.9.2 Preparation and Crystallographic Structures of the Two Polymorphs, γ-FePO4 and ζ-FePO4 622.9.3 Mössbauer Spectral Studies of FePO4 Metastable Polymorphs 642.9.4 Preparation and Mössbauer Spectra of Synthetic Heterosite, (Fe,Mn)PO4 672.9.5 Fits of the Magnetic Mössbauer Spectra of η-Fe 0.9 Mn 0.1 PO4 682.10 Mössbauer Spectral Studies of Various Iron Phosphate Compounds 732.10.1 Mössbauer Spectral Properties of α-Fe2 (PO4)O 742.10.2 Mössbauer Spectral Properties of Fe3 (PO4)O3 792.10.3 Preparation and Structural Properties of Fe9 (PO4)O8 802.10.4 Mössbauer Spectral Properties of Fe9 (PO4)O8 81Acknowledgments 85References and Notes 853 Mössbauer Spectroscopic Investigation of Fe-Based Silicides 93Xiao Chen, Junhu Wang, and Changhai Liang3.1 Introduction 933.2 Mössbauer Spectroscopic Investigation of Iron Silicides Prepared By Mechanical Alloying and Heat Treatment 953.3 Mössbauer Spectra of Iron Silicide on Silica Prepared by Pyrolysis of Ferrocene-Polydimethylsilane Composites 993.4 Synthesis and Mössbauer Spectra of Iron Silicides by Temperature-Programmed Silicification 1023.5 Mössbauer Spectroscopic Investigation of Doped Iron Silicides 1043.6 Conclusion and Perspective 107References 1084 Mössbauer Spectroscopy of Catalysts 113Károly Lázár4.1 Introduction 1134.2 Principles of the Mössbauer Effect and Outlook of Its Application for Catalyst Studies 1164.2.1 Brief Overview of the Basics of Mössbauer Spectroscopy 1164.2.2 Mössbauer Spectroscopy from the Point of View of Catalyst Studies – Particular Features 1174.2.3 The Probability of the Mössbauer Effect – f-Factor and Size Effects 1184.2.4 Variants of the Technique 1204.2.4.1 57Co Emission Spectroscopy 1204.2.4.2 Synchrotron-Based NFS (Nuclear Forward Scattering) 1224.2.4.3 Conversion Electron Mössbauer Spectroscopy 1224.2.5 Technical Implementations – Experimental Conditions 1234.3 Heterogeneous Catalysts 1244.3.1 Sites on Supported Particles with Different Participation in Catalytic Processes 1244.3.2 Collective Effects in Particles (Magnetism) 1254.3.3 Case Studies 1264.3.3.1 Metals and Alloys 1264.3.3.2 Oxide Catalysts 1304.3.3.3 Catalysts with Fe–N, Fe–C, and Fe–N–C Centers 1334.4 Biocatalysts – Enzymes 1354.5 Homogeneous Catalysts – Frozen Solutions 1354.5.1 Studies on Reaction Intermediates – Time-Resolved Freeze-Quenched Spectra 1364.6 Conclusions 137Acknowledgment 137References 1385 Application of Mössbauer Spectroscopy in Studying Catalysts for CO Oxidation and Preferential Oxidation of CO in H2145Kuo Liu, Junhu Wang, and Tao Zhang5.1 Introduction 1455.2 Application of Mössbauer Spectroscopy in CO Oxidation 1475.2.1 57 Fe Mössbauer Spectroscopy 1475.2.2 119 Sn Mössbauer Spectroscopy 1505.2.3 197 Au Mössbauer Spectroscopy 1515.2.4 193 Ir Mössbauer spectroscopy 1525.3 Application of Mössbauer Spectroscopy in PROX 1535.3.1 PtFe-Containing Catalysts 1535.3.2 Au-Based Catalysts 1555.3.3 IrFe-Containing Catalysts 1585.3.3.1 Porous Carbon Supported IrFe Catalysts 1585.3.3.2 SiO2 and Al2 O3 Supported IrFe Catalysts 1595.3.4 CuO/CeO2 with Fe2 O3 Additive 1655.4 Concluding Remarks 165Acknowledgments 166References 1666 Application of 57 Fe Mössbauer Spectroscopy in Studying Fe–N–C Catalysts for Oxygen Reduction Reaction in Proton Exchange Membrane Fuel Cells 171Xinlong Xu, Junhu Wang, Suli Wang, and Gongquan Sun6.1 Introduction 1716.2 Advanced 57Fe Mössbauer Spectroscopy Technique 1736.2.1 Room Temperature 57Fe Mössbauer Spectroscopy 1736.2.2 Low Temperature and Computational 57Fe Mössbauer Spectroscopy 1746.2.3 In Situ Electrochemical 57Fe Mössbauer Spectroscopy 1756.3 Characterization of Fe–N–C Using 57Fe Mössbauer Spectroscopy 1776.3.1 Identification of Active Sites 1776.3.2 Investigation of Degradation Mechanism 1806.3.3 Optimization for Synthesis of Fe–N–C 1846.3.3.1 Precursor Composition 1846.3.3.2 Heat Treatment 1856.4 Summary and Perspective 187Acknowledgments 188References 1887 197 Au Mössbauer Spectroscopy of Thiolate-protected Gold Clusters 195Norimichi Kojima, Yasuhiro Kobaqyashi, and Makoto Seto7.1 Introduction 1957.2 Synthesis of Thiolate Protected Gold Clusters 1977.3 197 Au Mössbauer Spectroscopy of Gold Nano-clusters 1987.3.1 Experimental Procedure of 197 Au Mössbauer Spectroscopy 1987.3.2 197 Au Mössbauer Spectra of Aun (SG)m(n = 10∼55) 1987.3.3 Molecular Structure and 197 Au Mössbauer Spectra of Au10 (SG)10 1987.3.4 Molecular Structure and 197 Au Mössbauer Spectra of Au25 (SG)18 2007.3.5 Structural Evolution of Aun (SG)m(n = 10∼55) Based on 197 Au Mössbauer Spectroscopy 2017.3.6 197 Au Mössbauer Spectra of Au24 Pd1 (SC12 H25)18 2047.3.7 197 Au Mössbauer Spectra of Aun (SC12 H25)m 2057.4 Conclusion 208Acknowledgments 208References 2098 197 Au Mössbauer Spectroscopy of Gold Mixed-Valence Complexes, Cs2 [AuI X2 ][AuIII Y4 ](X, Y = Cl, Br, I) and [NH3 (CH2)n NH3 ]2[(AuI I2)(AuIII I4)(I3)2](n= 7, 8) 213Norimichi Kojima, Yasuhiro Kobaqyashi, and Makoto Seto8.1 Introduction 2138.2 Experimental Procedure 2168.2.1 Synthesis and Characterization 2168.2.1.1 Cs2 [AuI X2][AuIII Y4 ](X,Y= Cl, Br, I) 2168.2.1.2 [NH3 (CH2)n NH3 ]2 [(AuI I2)(AuIII I4)(I3)2 ](n= 7, 8) 2178.2.2 197 Au Mössbauer Spectroscopy 2178.3 Crystal Structure of Cs2 [AuI X2][ AuIII X4](X,Y= Cl, Br, I) 2188.4 Chemical Bond of Au−Xin[AuI X2] − and [AuIII X4] − 2218.5 Mössbauer Parameters of 197 Au in [AuI X2] − and [AuIII X4 ] − 2238.5.1 Mössbauer Parameters of 197 Au in (C4 H9)4 N[AuI X2] and (C4 H9)4 N[AuIII Y4] 2248.5.1.1 Isomer Shift 2248.5.1.2 Quadrupole Splitting 2248.5.2 Mössbauer Parameters of 197 Au in Cs2 [AuI X2] [ AuIII Y4] (X = Cl, Br, I) 2258.5.2.1 Isomer Shift 2258.5.2.2 Quadrupole Splitting 2268.5.2.3 Analysis of 197 Au Mössbauer Parameters for Cs2 [AuI X2] [ AuIII Y4] 2268.6 Charge Transfer Interaction in Cs2 [AuI X2] [ AuIII Y4](X= Cl, Br, I) 2278.7 197 Au Mössbauer Spectra of Cs2 [AuI X2] [ AuIII Y4](X,Y= Cl, Br, I) 2288.7.1 Isomer Shift of AuI in Cs2 [AuI X2] [ AuIII Y4] 2288.7.2 Isomer Shift of AuIII in Cs2 [AuI X2] [ AuIII Y4] 2308.7.3 Quadrupole Splitting of AuI in Cs2 [AuI X2 ] [AuIII Y4 ] 2308.7.4 Quadrupole Splitting of AuIII in Cs2 [AuI X2] [AuIII Y4 ] 2318.8 Single Crystal 197 Au Mössbauer Spectra of Cs2 [AuI I2 ] [AuIII I4 ] 2318.8.1 Comparison of 197 Au Mössbauer Spectra Between Single Crystal and Powder Crystal 2318.8.2 Sign of EFG for AuI in [AuI I2 ] − and AuIII in [AuIII X4 ] − 2348.9 197 Au Mössbauer Spectra of Cs2 [AuI X 2 ] [AuIII X4 ](X= Cl, I) Under High Pressures 2358.9.1 Phase Diagram of Cs2 [AuI X2 ] [AuIII X4 ](X= Cl, Br, I) 2358.9.2 Origin of Metallic Mixed-Valence State in Cs2 [AuI Cl2 ] [AuIII Cl4 ] 2368.9.3 Au Valence Transition in Cs2 [Au II2 ] [AuIII I4 ] 2398.10 197 Au Mössbauer Spectra of [NH3 (CH2)n NH3 ]2 [(Au II2)(AuIII I4)(I3)2 ] (n = 7, 8) 2418.11 Conclusion 243Acknowledgments 244  References 2459 Temperature- and Photo-Induced Spin-Crossover in Molecule-Based Magnets 251Hiroko Tokoro, Kenta Imoto, and Shin-ichi Ohkoshi9.1 Introduction 2519.2 Spin-Crossover Phenomena in Cesium Iron Hexacyanidochromate Prussian Blue Analog 2529.3 Light-Induced Spin-Crossover Magnet in Iron Octacyanidoniobate Bimetal Assembly 2549.4 Chiral Photomagnetism and Light-Controllable Second Harmonic Light in Iron Octacyanidoniobate Bimetal Assembly 2589.5 Conclusion and Perspective 265References 26510 Developing a Methodology to Obtain New Photoswitchable Fe(II) Spin Crossover Complexes 271Varun Kumar and Yann Garcia10.1 Introduction and Context 27110.2 Introduction to a New Photo-responsive Anion: psca 27510.3 Combining Fe(II) and psca Together in a Single Compound 27610.4 Fe(II) Mononuclear Complexes with DMPP and psca Ligands 27810.5 1D Fe(II) Coordination Polymer with psca as Non-Coordinated Anions 28110.6 Conclusions and Perspectives 284References 28511 57 Fe Mössbauer Spectroscopy as a Prime Tool to Explore a New Family of Colorimetric Sensors 291li Sun, Weiyang li, and Yann Garcia11.1 Introduction and General Context 29111.2 Colorimetric Gas Sensors Based on Fe(II) Complexes 29211.3 Conclusions and Perspectives 306References 306Index 311