Chalcogenide Aerogels as Sorbents for Noble Gases (Xe, Kr).
High-surface-area molybdenum sulfide (MoSx) and antimony sulfide (SbSx) chalcogels were studied for Xe/Kr gas separation. The intrinsic soft Lewis basic character of the chalcogel framework is a unique property among the large family of porous materials and lends itself to a potential new approach toward the selective separation of Xe over Kr. Among these chalcogels, MoSxshows the highest Xe and Kr uptake, reaching 0.69 mmol g-1(1.05 mmol cm-3) and 0.28 mmol g-1(0.42 mmol cm-3) respectively, at 273 K and 1 bar. The corresponding isosteric heat of adsorption at zero coverage (Qst0) is 22.8 and 18.6 kJ mol-1and both are the highest among the selected chalcogels. The IAST (10:90) Xe/Kr selectivity at 273 K for MoSxis 6.0, whereas for SbSxchalcogels, it varies in the range 2.0-2.8. The higher formal charge of molybdenum, Mo4+, in MoSxversus that of antimony, Sb3+, in SbSxcoupled with its larger atomic size could induce higher polarizability in the MoSxframework and therefore higher Xe/Kr selectivity.
Department of Chemistry, Northwestern University , Evanston, Illinois 60208, United States.
Kota S
KS
Subrahmanyam
Department of Chemistry, University of Crete , Voutes, 71003 Heraklion, Greece.
Ioannis
http://orcid.org/0000-0003-0861-1407
I
Spanopoulos
Pacific Northwest National Laboratory , Richland, Washington 99352, United States.
Jaehun
J
Chun
Pacific Northwest National Laboratory , Richland, Washington 99352, United States.
Brian J
BJ
Riley
Pacific Northwest National Laboratory , Richland, Washington 99352, United States.
Praveen K
PK
Thallapally
Department of Chemistry, University of Crete , Voutes, 71003 Heraklion, Greece.
Pantelis N
PN
Trikalitis
Department of Chemistry, Northwestern University , Evanston, Illinois 60208, United States.
Mercouri G
http://orcid.org/0000-0003-2037-4168
MG
Kanatzidis
aerogels; chalcogenide; nuclear remediation; porous materials