I
Table of contents
Summary V
Streszczenie IX
概要 XIV
Abbreviations and symbols XVIII
List of author’s publications XX
Aim of the work 1
Introduction and literature review
1. Oxygen production and storage methods 4
1.1. Cryogenic liquefaction processes 5
1.2. Pressure-driven adsorption processes 8
1.3. Usage of membranes for the oxygen production 10
1.4. Comparison of the oxygen production methods 12
1.5. Oxygen storage systems 13
2. Oxygen storage in solids 16
2.1. Oxygen storage materials - introduction 17
2.2. Surface reactions and catalytic processes 18
2.3. Mechanism of oxygen incorporation into perovskite-type oxides 21
2.4. Oxygen storage materials systems 26
2.4.1. Ceria-based oxygen storage materials 26
2.4.2. Ln2O2S-Ln2O2SO4 systems 27
2.4.3. Ln1-xYxMnO3+δ systems 27
2.4.4. BaYMn2O5-BaYMn2O6 system 28
3. Application of oxygen storage materials 30
3.1. Three-way catalytic converters for automotive industry 30
3.2. Chemical looping combustion 33
3.3. Flameless methane combustion with BaYMn2O5+δ catalyst 35 3.4. Integrated Gasification Fuel Cell system with OSM-based unit 36 4. Physicochemical properties of perovskite-type oxides 37
4.1. Crystal structure of perovskite-type oxides 37
4.2. Nonstoichiometric perovskites 41
II 4.4. Physicochemical properties of ordered perovskite-type oxides 49
4.4.1. Perovskites with layered-type of A-site ordering 51 4.4.2. Perovskites with rock salt-type of B-site ordering 53 4.4.3. Anion vacancy-ordered brownmillerite-type structure 54 4.5. Oxygen nonstoichiometry in A-site layered AA’B2O5+δ 55 4.6. Transport properties of selected A-site layered AA’B2O5+δ 57 4.7. Electrical and magnetic properties of BaLnMn2O5+δ oxides 58
Methodology
5. Methodology 61
5.1. Selection of chemical composition of the materials 61
5.2. Preparation methods of the studied oxides 62
5.3. Structural characterization and Rietveld analysis 64
5.3.1. X-ray diffraction 65
5.3.2. Neutron diffraction 66
5.4. Thermogravimetric studies 67
5.5. Estimation of the activation energy of the oxygen transport 69
5.6. Microstructural studies 74
5.7. XPS measurements 74
5.8. Electrical conductivity and Seebeck coefficient measurements 75 5.9. Calculation of parameters for evaluation of the oxygen storage properties 75
Results and discussion
6. Properties of BaLnMn2O5+δ (Ln: Pr, Nd, Sm, Gd, Dy and Y) oxides 77 6.1. Crystal structure of BaLnMn2O5 and BaLnMn2O6 oxides at room
temperature 77
6.2. In situ structural measurements 82
6.2.1. Changes of the crystal structure during oxidation process 83 6.2.2. Changes of the crystal structure during reduction process in 5 vol.%
H2 in Ar and mechanism of oxygen release from BaLnMn2O6 oxides
85
6.2.3. Changes of the crystal structure during reduction process in vacuum 89
6.3. Microstructure of BaLnMn2O5+δ powders 92
III
6.5. Results of XPS studies 101
7. Properties of BaErMn2O5+δ oxides 107
7.1. Crystal structure of BaErMn2O5 and BaErMn2O6 oxides at room
temperature 107
7.2. In situ structural measurements 110
7.3. Microstructure of BaErMn2O5+δ powders 111
7.4. Oxygen storage properties 112
7.5. Electrical conductivity and Seebeck coefficient of BaErMn2O5+δ 113 8. Properties of BaY1-xLnxMn2O5+δ (Ln: Pr, Sm, Gd) oxides 116 8.1. Partial substitution of Pr into BaY1-xPrxMn2O5+δ (0 < x < 1) system 116
8.1.1. Crystal structure of BaY1-xPrxMn2O5 and BaY1-xPrxMn2O6 oxides at
room temperature 117
8.1.2. Oxygen storage properties 119
8.1.3. Cycling performance of BaY0.75Pr0.25Mn2O5+δ 121 8.2. Partial substitution of Sm into BaY1-xSmxMn2O5+δ (0 < x < 1) system 123
8.2.1. Crystal structure of BaY1-xSmxMn2O5 and BaY1-xSmxMn2O6 oxides
at room temperature 123
8.2.2. Oxygen storage properties 125
8.3. Partial substitution of Gd into BaY1-xGdxMn2O5+δ (0 < x < 1) system 127 8.3.1. Crystal structure of BaY1-xGdxMn2O5 and BaY1-xGdxMn2O6 oxides
at room temperature 127
8.3.2. Oxygen storage properties 129
8.3.3. Ionic transport in BaY1-xGdxMn2O5+δ 131
9. Properties of Ba0.9Sr0.1Y1-xLnxMn2O5+δ (Ln: Pr, Sm, Gd) oxides 134 9.1. Crystal structure of Ba0.9Sr0.1Y1-xLnxMn2O5 and Ba0.9Sr0.1Y1-xLnxMn2O6
oxides at room temperature 134
9.2. Microstructure of Ba0.9Sr0.1Y1-xLnxMn2O5+δ powders 137
9.3. Oxygen storage properties 138
9.4. Cycling performance of Ba0.9Sr0.1Y0.75Sm0.25Mn2O5+δ 140 9.5. Ionic transport in selected Ba0.9Sr0.1Y1-xLnxMn2O5+δ 141 10. Properties of Co- and Fe-containing perovskite-type oxides 143
10.1. Crystal structure of reduced and oxidized Co- and Fe-containing
IV
10.2. In situ structural measurements 146
10.3. Microstructure of powders 150
10.4. Oxygen storage properties 151
10.5. Cycling performance of La0.5Sr0.5Co0.5Fe0.5O3-δ 154 10.6. Ionic transport in Co- and Fe-containing perovskite-type oxides 154
11. Conclusions and recommendations 157
Appendix A 166 Appendix B 169 Appendix C 181 Appendix D 186 References 189 Appendix references 200
