Layered Mg-Al spinel supported Ce-Fe-Zr-O oxygen carriers for chemical looping reforming

• Published in: Chinese journal of chemical engineering 2020-10, Vol.28 (10), p.2668-2676
• Main Authors: Yuan, Jiangyong, Zhao, Yannan, Xu, Haiwen, Lu, Chunqiang, Yang, Kun, Zhu, Xing, Li, Kongzhai
• Format: Article
• Language: English
• Subjects: Ce-Fe-Zr-O(x)/MgAl-LDO; Chemical looping reforming; Hydrogen; Oxygen carrier; Syngas
• ISSN: 1004-9541; 2210-321X
• DOI: 10.1016/j.cjche.2020.06.035

A series of layered Mg-Al spinel supported Ce-Fe-Zr-O oxygen carriers were prepared for co-production of syngas and pure hydrogen via chemical looping steam reforming (CLSR). The presence of magnesium-aluminum layered double oxides (MgAl-LDO) significantly increases the specific surface area of the mixed oxides, reduces the particle size of CeO2-based solid solution and promotes the dispersion of free Fe2O3. When reacting with methane, MgAl-LDO supported oxygen carrier shows much lower temperature for methane oxidation than the pure Ce-Fe-Zr-O sample, indicating enhanced low-temperature reactivity. Among different Ce-Fe-Zr-O(x)/MgAl-LDO samples, the Ce-Fe-Zr-O(40 wt%)/MgAl-LDO sample shows the best performance for the selective oxidation of methane to syngas and the H2 production by water splitting. After a long period of high temperature redox experiment, the Ce-Fe-Zr-O(40 wt%)/MgAl-LDO oxygen carrier still shows high activity for syngas generation. The comparison on the morphology of the fresh and cycled oxygen carriers indicates that the Mg-Al spinel support still forms a stable skeleton structure with high dispersion of active components on the surface after the long-term cycling, which contributes to excellent redox stability of the Ce-Fe-Zr-O(40 wt%)/MgAl-LDO oxygen carrier. In this work, layered Mg-Al spinel supported Ce-Fe-Zr-O oxygen carriers were prepared for chemical looping steam reforming. The effects of structural evolution and the interaction between the supports and the active components on the redox performances of the samples were studied in detail to understand the reaction mechanism. [Display omitted]