چکیده
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The oxidation of carbon monoxide (CO) is
important for a series of technological and environmental
applications. In this work, the catalytic oxidation of CO on
Si-doped (6,0) boron nitride nanotubes (BNNTs) is inves-
tigated by using density functional theory calculations.
Reaction barriers and corresponding thermodynamic pa-
rameters were calculated using the M06-2X, B3LYP and
wB97XD density functionals with 6-31G* basis set. Our
results indicate that a vacancy defect in BNNT strongly
stabilizes the Si adatom and makes it more positively
charged. This charging enhances the adsorption of reaction
gases (O 2 and CO) and results in the change of the elec-
tronic structure properties of the tube. The calculated bar-
rier of the reaction CO ? O 2 ? CO 2 ? O ads on Si-doped
BNNTs following the Langmuir–Hinshelwood is lower
than that on the traditional noble metal catalysts. The
second step of the oxidation would be the Eley–Rideal
reaction (CO ? O ads ? CO 2 ) with an energy barrier of
about 1.8 and 10.1 kcal/mol at M06-2X/6-31G* level. This
suggests that the CO oxidation catalyzed by the Si-doped
BNNTs is likely to occur at the room temperature. The
results also demonstrate that the activation energies and
thermodynamic quantities calculated by M06-2X, B3LYP
and wB97XD functionals are consistent with each other.
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