Iron oxide redox reaction with oxide ion conducting supports for hydrogen production and storage systems
Iron oxide redox reaction with oxide ion conducting supports for hydrogen production and storage systems
复制标题
DOI：
10.1016/j.ces.2014.11.012
复制
发表时间：
2015-02
影响因子：
4.7
通讯作者：
Fumihiko Kosaka;H. Hatano;Y. Oshima;J. Otomo
中科院分区：
文献类型：
--
作者：
Fumihiko Kosaka;H. Hatano;Y. Oshima;J. Otomo
氧化还原反应动力学的改进对于金属氧化物氧化还原反应在化学环系统和储氢等能量转换系统中的应用具有重要意义。在本研究中，我们重点研究了影响金属氧化物氧化还原反应动力学的载体的物理性质。采用具有不同物理性质的氧化离子和电导率的载体材料ZrO2、CeO2、钇稳定氧化锆（YSZ）和钆掺杂氧化铈（GDC），研究了氢和水蒸气对氧化铁的氧化还原反应。YSZ和GDC等氧化物离子导体明显提高了Fe2O3还原速率（Fe2O3→Fe3O4→FeO→Fe）。这一结果表明，载体中的氧空位和良好的氧化离子传输特性可能会促进氧化铁中氧的去除。此外，ceo2和GDC显著改善了FeO到Fe还原步骤的还原动力学。此外，与ZrO2相比，这些载体对水蒸气氧化铁的反应动力学有影响；也就是说，它们增加了蒸汽-铁反应制氢的速率。从载体中的氧化离子和电子电导率以及载体表面的水解离等方面讨论了改进的机理。
Improvement of redox reaction kinetics is important for the application of metal oxide redox reactions in energy conversion systems such as chemical looping systems and hydrogen storage. In this study, we focused on physical properties in supports that can affect the redox reaction kinetics of metal oxides. The redox reaction of iron oxide by hydrogen and water vapor was studied with various support materials, ZrO2, CeO2, yttria-stabilized zirconia (YSZ) and gadolinia-doped ceria (GDC), which have different physical properties such as oxide ion and electronic conductivities. Oxide ion conductors such as YSZ and GDC clearly increased the rate of Fe2O3reduction (Fe2O3→Fe3O4→FeO→Fe). This result suggests that oxygen vacancies and good oxide ion transport properties in the supports may enhance removal of oxygen from iron oxide. In addition, CeO2and GDC significantly improved the reduction kinetics in the reduction step from FeO to Fe. Furthermore, it was found that these supports have an effect on the oxidation reaction kinetics of iron by water vapor in comparison with ZrO2; that is, they increase the rate of the steam-iron reaction for hydrogen production. The mechanism of the improvement was discussed in terms of oxide ion and electronic conductivity in the supports and water dissociation on the support surfaces.