Mg-Ion Inversion in MgO@Al2O3 Oxides: The Origin of Basic Sites
- Title
- Mg-Ion Inversion in MgO@Al2O3 Oxides: The Origin of Basic Sites
- Author
- 서정길
- Keywords
- carbon capture; metal oxides; sorbents; spinel phases; structure elucidation
- Issue Date
- 2019-06
- Publisher
- WILEY-V C H VERLAG GMBH
- Citation
- CHEMSUSCHEM, v. 12, NO 12, Page. 2810-2818
- Abstract
- Although MgO-Al2O3 is well known as having a spinel structure, the inversion of which occurs by exchange of the trivalent (Al3+) and divalent (Mg2+) cations, little analytical study of the degree of inversion has been carried out. This study concerns a simple methodology to identify the inversion by solid-state NMR spectroscopy, whereby its correlation with the CO2 capture capacity of MgO-rich MgO@MgO-Al2O3 spinel structures is verified. Through Al-27 and Mg-25 NMR spectroscopy, temperature-programmed CO2 desorption, and thermogravimetric analysis, higher inversion is found to occur at low Mg/Al ratios and the inversion is found to decrease as the Mg/Al ratio increases. Moreover, the degree of inversion correlates with CO2 sorption, which is associated with the medium-strength basic sites induced by formation of the unsaturated O2- species. These results will open new pathways to exploit defects in complex oxides beyond spinels and their derivatives for desired applications. This demonstration of MgO-Al2O3 for CO2 sorption can contribute to the design of future CO2 sorbents.
- URI
- https://onlinelibrary.wiley.com/doi/full/10.1002/cssc.201900072https://repository.hanyang.ac.kr/handle/20.500.11754/151048
- ISSN
- 1864-5631; 1864-564X
- DOI
- 10.1002/cssc.201900072
- Appears in Collections:
- COLLEGE OF ENGINEERING[S](공과대학) > CHEMICAL ENGINEERING(화학공학과) > Articles
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