Effect of Spin Multiplicity in O<sub>2</sub> Adsorption
and Dissociation on Small Bimetallic AuAg Clusters
Raúl García-Cruz
Enrique Poulain
Isaías Hernández-Pérez
Juan A. Reyes-Nava
Julio C. González-Torres
A. Rubio-Ponce
Oscar Olvera-Neria
10.1021/acs.jpca.7b01968.s001
https://acs.figshare.com/articles/journal_contribution/Effect_of_Spin_Multiplicity_in_O_sub_2_sub_Adsorption_and_Dissociation_on_Small_Bimetallic_AuAg_Clusters/5281879
To dispose of atomic
oxygen, it is necessary the O<sub>2</sub> activation;
however, an energy barrier must be overcome to break the O–O
bond. This work presents theoretical calculations of the O<sub>2</sub> adsorption and dissociation on small pure Au<sub><i>n</i></sub> and Ag<sub><i>m</i></sub> and bimetallic Au<sub><i>n</i></sub>Ag<sub><i>m</i></sub> (<i>n</i> + <i>m</i> ≤ 6) clusters using the density
functional theory (DFT) and the zeroth-order regular approximation
(ZORA) to explicitly include scalar relativistic effects. The most
stable Au<sub><i>n</i></sub>Ag<sub><i>m</i></sub> clusters contain a higher concentration of Au with Ag atoms located
in the center of the cluster. The O<sub>2</sub> adsorption energy
on pure and bimetallic clusters and the ensuing geometries depend
on the spin multiplicity of the system. For a doublet multiplicity,
O<sub>2</sub> is adsorbed in a bridge configuration, whereas for a
triplet only one O–metal bond is formed. The charge transfer
from metal toward O<sub>2</sub> occupies the σ*<sub>O–O</sub> antibonding natural bond orbital, which weakens the oxygen bond.
The Au<sub>3</sub> (<sup>2</sup>A) cluster presents the lowest activation
energy to dissociate O<sub>2</sub>, whereas the opposite applies to
the AuAg (<sup>3</sup>A) system. In the O<sub>2</sub> activation,
bimetallic clusters are not as active as pure Au<sub><i>n</i></sub> clusters due to the charge donated by Ag atoms being shared
between O<sub>2</sub> and Au atoms.
2017-07-05 00:00:00
bimetallic clusters
O 2 adsorption energy
O 2 Adsorption
Ag atoms
O 2 activation
O 2 adsorption
O 2
DFT
n Ag m
n Ag m clusters
Small Bimetallic AuAg Clusters
ZORA
bond