Ab Initio Investigation of the Adsorption of CO2 on Fe13 Cluster

Abstract

A large number of adsorption sites were
explored for the CO2/Fe13 system. The
adsorption sites found were classified in
the top, bridge, and hollow, and the
more reactive site was identified based
on the adsorption energy. The structure
with the lowest adsorption energy
showed that the molecule is bent in a
bridge adsorption site. The results of
charge distribution, the difference of
density, and the vibrational frequencies
reveal that a charge transfer from the
cluster to the molecule occurs. Which
partially
explains
the
geometry
modification of adsorbed CO2. This result
is interesting since this charge transfer
is desirable for the activation of CO2 and
subsequent reduction of the molecule
into valued products.

Full text

METHODOLOGY
RESULTS AND DISCUSSIN
Ab Initio Investigation of the Adsorption of CO2on Fe13 Cluster
Vivianne K. Ocampo-Restrepo, Larissa Zibordi-Besse, and Juarez L. F. Da Silva
So Carlos Institute of Chemistry, University of So Paulo, PO Box 780, 13560 -970, So Carlos, SP, Brazil
vivianne.o.restrepo@iqsc.usp.br
ACKNOWLEDGMENTS
REFERENCES
1. Homs, N.; Toyir, J.; de la Piscina, P. R. In
New and Future Developments in
Catalysis; Suib, S. L., Ed.; Elsevier:
Amsterdam, 2013;pp 1 - 26.
2. Diego Guedes-Sobrinho, Ricardo K
Nomiyama, Anderson S Chaves, Maurício J
Piotrowski, Juarez LF Da Silva. J. Phys.
Chem. C,2015,119 (27), pp 15669-
15679.
3. Anderson S Chaves, Maurício J Piotrowski,
Juarez LF Da Silva. Phys. Chem. Chem.
Phys.,2017,19 (23), pp 15484-15502.
4. Tomasz Ossowski, Juarez LF Da Silva,
Adam Kiejna. Surface Science,2018,668,
pp 144-149.
CONCLUSION
A large number of adsorption sites were
explored for the CO2/Fe13 system. The
adsorption sites found were classified in
the top, bridge, and hollow, and the
more reactive site was identified based
on the adsorption energy. The structure
with the lowest adsorption energy
showed that the molecule is bent in a
bridge adsorption site. The results of
charge distribution, the difference of
density, and the vibrational frequencies
reveal that a charge transfer from the
cluster to the molecule occurs. Which
partially explains the geometry
modification of adsorbed CO2. This result
is interesting since this charge transfer
is desirable for the activation of CO2and
subsequent reduction of the molecule
into valued products.
INTRODUCTION
Study the adsorption of CO2on Fe13 cluster as
a first step in the overall reduction process.
Greenhouse effect
Density Functional Theory
PBE and PBE + vdW
Numerical atomic orbitals
METHODOLOGY
Theoretical approach
Adsorption structures generation
RESULTS AND DISCUSSION
Figure 1. Representation of adsorption sites
found. The interaction between the molecule
and Fe13 are named the top, the bridge, and
the hollow.
Figure 2. Representative structures studied in relation to their
adsorption energy. The number close to the structure is the
minimum distance in Å. The dashed lines are used to represent
the long-range interaction between molecule and cluster.
Adsorption structures of CO2/Fe13
Figure 3. (a) The lower energy structure and
adsorption energy EadPPBE+vdW in eV. (b)
Electron density difference and the charge
distribution in the CO2DqCO2in quantity of e
b)
Figure 4. Infrared spectra of CO2,CO2-,Fe13, and CO2/Fe13.
The infrared intensity for the Fe13 cluster were multiplied by
50 for visualization purpose.
EadPPBE+vdW = -1.16
DqCO2= -0.25
a)
Lower energy structure of CO2/Fe13