In:
Advanced Functional Materials, Wiley, Vol. 33, No. 40 ( 2023-10)
Abstract:
To advance CaO‐based CO 2 sorbents it is crucial to understand how their structural parameters control the cyclic CO 2 uptake. Here, CaO‐based sorbents with varying ratios of Na 2 CO 3 :CaCO 3 are synthesized via mechanochemical activation of a mixture of Na 2 CO 3 and CaCO 3 to investigate the effect of sodium species on the structure, morphology, carbonation rate and cyclic CO 2 uptake of the CO 2 sorbents. The addition of Na 2 CO 3 in the range of 0.1–0.2 mol% improves the CO 2 uptake by up to 80% after 10 cycles when compared to ball‐milled bare CaCO 3 , while for Na 2 CO 3 loadings 〉 0.3 mol% the cyclic CO 2 uptake decreases by more than 40%. Energy dispersive X‐ray spectroscopy (EDX), transmission electron microscopy, X‐ray absorption spectroscopy (XAS), and 23 Na MAS NMR, reveal that in sorbents with Na 2 CO 3 contents 〈 0.3 mol% Na exists in highly distributed, noncrystalline [Na 2 Ca(CO 3 ) 2 ] units. These species stabilize the surface area of the sorbent in pores of diameters 〉 100 nm, and enhance the diffusion of CO 2 through CaCO 3 . For Na 2 CO 3 contents 〉 0.3 mol%, the accelerated deactivation of the sorbents via sintering is related to the formation of crystalline Na 2 Ca(CO 3 ) 2 and the high mobility of Na.
Type of Medium:
Online Resource
ISSN:
1616-301X
,
1616-3028
DOI:
10.1002/adfm.202302916
Language:
English
Publisher:
Wiley
Publication Date:
2023
detail.hit.zdb_id:
2029061-5
detail.hit.zdb_id:
2039420-2
SSG:
11
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