MgO insertion endowed strong basicity in mesoporous alumina framework and improved CO2 sorption capacity. Issue 42 (December 2020)

• Record Type: Journal Article
• Authors: Hiremath, Vishwanath; Shiferraw, Bezawit Tatek; Seo, Jeong Gil
• Is Part Of: Journal of CO₂ utilization. Issue 42(2020)
• Publication Date: 2020-12
• Subjects: Mesoporous alumina -- Surface basicity -- Solid state 27Al-NMR -- Thermal stability; Carbon dioxide -- Periodicals; Carbon dioxide -- Environmental aspects -- Periodicals; Carbon dioxide mitigation -- Periodicals; Carbon dioxide; Carbon dioxide -- Environmental aspects; Carbon dioxide mitigation; Periodicals; 628.53205
• DOI: 10.1016/j.jcou.2020.101294
• Languages: English
• ISSNs: 2212-9820

Abstract

Graphical Abstract : Highlights: Highly mesoporous alumina 2D nanoflakes with tunable textural properties were developed. A superior textural properties corresponding to >300 m 2 /g was obtained without the aid of templating agents. The incorporation of MgO in to the alumina framework enhance the basic properties. The MgO-Al2 O3 composites show excellent cyclic stability for elevated temperature CO2 capture. Abstract: Fine tuning the electronic properties of amorphous mesoporous alumina has been extensively studied due to its wide range of applications. Luckily, fundamental changes via secondary metal atom insertion has been broadly recognized and pave the way towards development of novel materials. In this study, structure-property correlation of mesoporous alumina framework has been evaluated for elevated temperature application via MgO insertion. The pristine Al2 O3 possess an excellent specific surface area corresponding to 319 m 2 /g with average pore diameter of 14.8 nm. However, surface area and pore diameter were linearly decreased as a function of hydrothermal temperature. Remarkably, MgO insertion improved its specific surface area to 357 m 2 /g with narrow pore size distribution at 7.1 nm. The improved surface area is due to the coexistence of MgO with Al2 O3 in its amorphous framework. Meanwhile, the improved CO2 sorption capacity attributed to the induced strong basic sites via MgO insertion and better kinetics is due to the appropriate pore structure of the derived nano-composite. Further, the heterogeneity of the alumina framework with 6-coordinated and 4-coordinated environment established improved basicity as suggested by solid state 27 Al-NMR and CO2 -TPD results. The developed composite shows excellent thermal stability for temperature swing CO2 desorption with 95% retainment in its sorption capacity.