Molecular level insights into the mechanism and thermodynamics of CO
oxidation by a (TiO) cluster have been
obtained through density functional calculations. Thereby, we have
considered as an example, two different structural isomers of
(TiO) with the purpose of
understanding the interplay between local structure and activity for the
CO oxidation reaction. Active sites in the two isomeric forms were
identified on the basis of global and local reactivity descriptors. For
the oxidation of CO to CO2 we considered both sequential and
simultaneous adsorption of CO and O2 on (TiO2)6 cluster through the ER
and LH mechanisms, respectively. Three different pathways were obtained
for CO oxidation by (TiO2)6 cluster, and the mechanistic route of each
pathway were identified by locating the transition-state and
intermediate structures. The effects of temperature on the rate of the
reaction was investigated within the harmonic approximation. The
structure-dependent activity of the cluster was rationalized through
reactivity descriptors and analysis of the frontier orbitals. Finally,
we also considered the effects of a support, i.e., graphene, on the
oxidation mechanism.
Kinetics and Thermodynamics of CO Oxidation by (TiO2)6
