In:
ChemSusChem, Wiley, Vol. 12, No. 12 ( 2019-06-21), p. 2810-2818
Abstract:
Although MgO−Al 2 O 3 is well known as having a spinel structure, the inversion of which occurs by exchange of the trivalent (Al 3+ ) and divalent (Mg 2+ ) 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 CO 2 capture capacity of MgO‐rich MgO@MgO−Al 2 O 3 spinel structures is verified. Through 27 Al and 25 Mg NMR spectroscopy, temperature‐programmed CO 2 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 CO 2 sorption, which is associated with the medium‐strength basic sites induced by formation of the unsaturated O 2− 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−Al 2 O 3 for CO 2 sorption can contribute to the design of future CO 2 sorbents.
Type of Medium:
Online Resource
ISSN:
1864-5631
,
1864-564X
DOI:
10.1002/cssc.201900072
Language:
English
Publisher:
Wiley
Publication Date:
2019
detail.hit.zdb_id:
2411405-4
Permalink