Abstract
MgO sorbents doped with alkali-metal carbonates have been shown to exhibit improved sorption capacities at both low and moderate operating temperatures, compared to pure MgO sorbents. However, the mechanism of how alkali-metal carbonates enhance the CO2 sorption is not well understood. Using in situ X-ray diffraction, TEM, and thermogravimetric analysis, we have shown that the cesium dopants in the Cs2CO3-doped MgO nanoparticle system do not simply act as a promoter in sorption of CO2, but rather as a reagent alongside MgO. A new mixed magnesium-cesium carbonate phase has been found to be responsible for the improved sorption capacity of the doped-MgO-based sorbents. On the basis of our findings, it is suggested that a higher sorption capacity may be achieved if cesium is uniformly dispersed throughout the MgO particles.
Original language | English (US) |
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Pages (from-to) | 17514-17520 |
Number of pages | 7 |
Journal | Journal of Physical Chemistry C |
Volume | 117 |
Issue number | 34 |
DOIs | |
State | Published - Aug 29 2013 |
Externally published | Yes |
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Energy(all)
- Physical and Theoretical Chemistry
- Surfaces, Coatings and Films