Preparation of double perovskite-type oxide LaSrFeCoO6 for chemical looping steam methane reforming to produce syngas and hydrogen
来源期刊：Journal of Rare Earths2016年第10期
论文作者：赵坤 沈阳 何方 黄振 魏国强 郑安庆 李海滨 赵增立
文章页码：1032 - 1041
摘 要：Double-perovskite type oxide LaSrFeCoO6 was used as oxygen carrier for chemical looping steam methane reforming（CL-SMR） due to its unique structure and reactivity. Solid-phase, amorphous alloy, sol-gel and micro-emulsion methods were used to prepare the LaSrFeCoO6 samples, and the as-prepared samples were characterized by means of X-ray diffraction（XRD）, hydrogen temperature-programmed reduction（H2-TPR）, X-ray photoelectron spectroscopy（XPS）, Brunauer-Emmett-Teller（BET） surface area. Results showed that the samples made by the four different methods exhibited pure crystalline perovskite structure. The ordered double perovskite LaSrFeCoO6 was regarded as a regular arrangement of alternating FeO6 and CoO6 corner-shared octahedra, with La and Sr cations occupying the voids in between the octahedral. Because the La3+ and Sr2+ ions in A-site did not take part in reaction, the TPR patterns showed the reductive properties of the B-site metals. The reduction peaks at low temperature revealed the reduction of adsorbed oxygen on surface and combined with the reduction of Co3+ to Co2+ and to Co0, while the reduction of Fe3+ to Fe2+ and the partial reduction of Fe2+ to Fe0 occurred at higher temperatures. From the point of view of the oxygen-donation ability, resistance to carbon formation, as well as hydrogen generation capacity, the sample made by micro-emulsion method exhibited the best reactivity. Its redox reactivity was very stable in ten successive cycles without deactivation. Compared to the single perovskite-type oxides LaFeO3 and LaCoO3, the double perovskite LaSrFeCoO6 exhibited better syngas and hydrogen generation capacity.
赵坤1,2,3，沈阳3，何方1，黄振1，魏国强1，郑安庆1，李海滨1，赵增立1
1. Key Laboratory of Renewable Energy, Chinese Academy of Sciences, Guangzhou Institute of Energy Conversion, Chinese Academy of Sciences2. Guangdong Key Laboratory of New and Renewable Energy Research and Development, Guangzhou Institute of Energy Conversion, Chinese Academy of Sciences3. University of Chinese Academy of Sciences
摘 要：Double-perovskite type oxide LaSrFeCoO6 was used as oxygen carrier for chemical looping steam methane reforming（CL-SMR） due to its unique structure and reactivity. Solid-phase, amorphous alloy, sol-gel and micro-emulsion methods were used to prepare the LaSrFeCoO6 samples, and the as-prepared samples were characterized by means of X-ray diffraction（XRD）, hydrogen temperature-programmed reduction（H2-TPR）, X-ray photoelectron spectroscopy（XPS）, Brunauer-Emmett-Teller（BET） surface area. Results showed that the samples made by the four different methods exhibited pure crystalline perovskite structure. The ordered double perovskite LaSrFeCoO6 was regarded as a regular arrangement of alternating FeO6 and CoO6 corner-shared octahedra, with La and Sr cations occupying the voids in between the octahedral. Because the La3+ and Sr2+ ions in A-site did not take part in reaction, the TPR patterns showed the reductive properties of the B-site metals. The reduction peaks at low temperature revealed the reduction of adsorbed oxygen on surface and combined with the reduction of Co3+ to Co2+ and to Co0, while the reduction of Fe3+ to Fe2+ and the partial reduction of Fe2+ to Fe0 occurred at higher temperatures. From the point of view of the oxygen-donation ability, resistance to carbon formation, as well as hydrogen generation capacity, the sample made by micro-emulsion method exhibited the best reactivity. Its redox reactivity was very stable in ten successive cycles without deactivation. Compared to the single perovskite-type oxides LaFeO3 and LaCoO3, the double perovskite LaSrFeCoO6 exhibited better syngas and hydrogen generation capacity.
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