Research output: Contribution to journal › Article › peer-review
Infrared spectroscopic evidence for two ways of adsorbed CO coordination. / Tsyganenko, A. A.; Otero Arean, C.; Escalona Platero, E.
In: Studies in Surface Science and Catalysis, Vol. 130 D, 01.01.2000, p. 3143-3148.Research output: Contribution to journal › Article › peer-review
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TY - JOUR
T1 - Infrared spectroscopic evidence for two ways of adsorbed CO coordination
AU - Tsyganenko, A. A.
AU - Otero Arean, C.
AU - Escalona Platero, E.
PY - 2000/1/1
Y1 - 2000/1/1
N2 - By FTIR spectroscopy at variable temperatures it was shown that CO interacts with extraframework alkali or Ca2+ cations in zeolites to form both M⋯CO and M⋯OC species that are in a temperature dependent equilibrium. The C-bonded species have always higher adsorption energy and account for the strong high-frequency vCO band, while the O-bonded structures reveal themselves in a weak band shifted to lower wavenumbers with respect to the free CO molecule. The difference between the energies of C- and O-bonded species depends upon the cation, and to some extent on the zeolite framework. These CO reorientation energy values, as well as the frequency shifts are well reproduced by a simple electrostatic model of dipole-cation interaction. For CaY zeolite, where two CO molecules can be adsorbed on the same cation, the presence of O-bonded molecules accounts for additional frequency increase of the adjacent CO, that could be interpreted as adsorption-induced increase of Lewis acidity.
AB - By FTIR spectroscopy at variable temperatures it was shown that CO interacts with extraframework alkali or Ca2+ cations in zeolites to form both M⋯CO and M⋯OC species that are in a temperature dependent equilibrium. The C-bonded species have always higher adsorption energy and account for the strong high-frequency vCO band, while the O-bonded structures reveal themselves in a weak band shifted to lower wavenumbers with respect to the free CO molecule. The difference between the energies of C- and O-bonded species depends upon the cation, and to some extent on the zeolite framework. These CO reorientation energy values, as well as the frequency shifts are well reproduced by a simple electrostatic model of dipole-cation interaction. For CaY zeolite, where two CO molecules can be adsorbed on the same cation, the presence of O-bonded molecules accounts for additional frequency increase of the adjacent CO, that could be interpreted as adsorption-induced increase of Lewis acidity.
UR - http://www.scopus.com/inward/record.url?scp=0034350970&partnerID=8YFLogxK
M3 - Article
AN - SCOPUS:0034350970
VL - 130 D
SP - 3143
EP - 3148
JO - Studies in Surface Science and Catalysis
JF - Studies in Surface Science and Catalysis
SN - 0167-2991
ER -
ID: 41682824