Discovering the active sites for C3 separation in MIL-100(Fe) by using operando IR spectroscopy.
A reducible MIL-100(Fe) metal-organic framework (MOF) was investigated for the separation of a propane/propene mixture. An operando methodology was applied (for the first time in the case of a MOF) in order to shed light on the separation mechanism. Breakthrough curves were obtained as in traditional separation column experiments, but monitoring the material surface online, thus providing evidences on the adsorption sites. The qualitative and quantitative analyses of Fe(II) and, to some extent, Fe(III) sites were possible, upon different activation protocols. Moreover, it was possible to identify the nature and the role of the active sites in the separation process by selective poisoning of one family of sites: it was clearly evidenced that the unsaturated Fe(II) sites are mainly responsible for the separation effect of the propane/propene mixture, thanks to their affinity for the unsaturated bonds, such as the C=C entities in propene. The activity of the highly concentrated Fe(III) sites was also highlighted.
Laboratoire Catalyse et Spectrochimie, ENSICAEN, Université de Caen, CNRS, 6, Boulevard Maréchal Juin, 14050 Caen, France.
Stefan
S
Wuttke
Philippe
P
Bazin
Alexandre
A
Vimont
Christian
C
Serre
You-Kyong
YK
Seo
Young Kyu
YK
Hwang
Jong-San
JS
Chang
Gérard
G
Férey
Marco
M
Daturi
D000475:Alkenes / Q000737:chemistry*; D020134:Catalytic Domain; D005290:Ferric Compounds / Q000737:chemistry*; D005296:Ferrous Compounds / Q000737:chemistry*; D011407:Propane / Q000737:chemistry*; D013055:Spectrophotometry, Infrared; D019265:Spectroscopy, Near-Infrared
D000475:Alkenes; D005290:Ferric Compounds; D005296:Ferrous Compounds; C013658:propylene; D011407:Propane