Material Analysis of Coated Siliconized Silicon Carbide (SiSiC) Honeycomb Structures for Thermochemical Hydrogen Production.
Material Analysis of Coated Siliconized Silicon Carbide (SiSiC) Honeycomb Structures for Thermochemical Hydrogen Production.
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DOI：
10.3390/ma6020421
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发表时间：
2013-01-31
期刊：
影响因子：
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通讯作者：
Pitz-Paal R
中科院分区：
文献类型：
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作者：
Neises-von Puttkamer M;Simon H;Schmücker M;Roeb M;Sattler C;Pitz-Paal R
在本工作中，热化学分解水与硅化碳化硅（SiSiC）蜂窝涂有铁酸锌氧化还原材料进行了研究。在实验室试验台中测试小规模涂覆的整料，并通过X射线衍射法（XRD）和扫描电子显微镜（SEM）表征，测试后进行相应的微观分析，以表征形貌和组成的变化。几个处理过的整料的比较揭示了各种反应产物的形成，如SiO2，锆英石（ZrSiO4），硅化铁（FeSi）和铁铝尖晶石（FeAl2O4），表明涂层的不同相之间以及涂层和SiSiC衬底之间的各种副反应的发生。研究表明，铁素体主要通过与SiSiC基体中存在的硅（Si）和碳化硅（SiC）反应而被还原。这些结果导致该系统的一个新的氧化还原机制的配方，其中锌铁氧体通过Si形成二氧化硅（SiO2）和通过SiC形成SiO2和一氧化碳被还原。在第一个20个周期内的氢产量下降建议是由于二氧化硅和锆石层的生长，作为反应物种的扩散屏障。
In the present work, thermochemical water splitting with siliconized silicon carbide (SiSiC) honeycombs coated with a zinc ferrite redox material was investigated. The small scale coated monoliths were tested in a laboratory test-rig and characterized by X-ray diffractometry (XRD) and Scanning Electron Microscopy (SEM) with corresponding micro analysis after testing in order to characterize the changes in morphology and composition. Comparison of several treated monoliths revealed the formation of various reaction products such as SiO2, zircon (ZrSiO4), iron silicide (FeSi) and hercynite (FeAl2O4) indicating the occurrence of various side reactions between the different phases of the coating as well as between the coating and the SiSiC substrate. The investigations showed that the ferrite is mainly reduced through reaction with silicon (Si), which is present in the SiSiC matrix, and silicon carbide (SiC). These results led to the formulation of a new redox mechanism for this system in which Zn-ferrite is reduced through Si forming silicon dioxide (SiO2) and through SiC forming SiO2 and carbon monoxide. A decline of hydrogen production within the first 20 cycles is suggested to be due to the growth of a silicon dioxide and zircon layer which acts as a diffusion barrier for the reacting specie.