Table 1 Reaction barriers and free energies*.

From: Unidirectional suppression of hydrogen oxidation on oxidized platinum clusters

Reaction

Pt 8 O 8 /TiO 2

Pt 12 /TiO 2

  

E a

Δ G

E a

Δ G

O2 adsorption

O2+*→O2*

/

0.14

/

−1.67

O2* dissociation

O2*+*→2O*

0.62

−0.27

0.49

−1.51

H2 adsorption

H2+*→H2*

/

0.34

/

−1.06

H2* dissociation

H2*+*→2 H*

0.17

−0.32

/

 

OH* formation

O*+H*→OH*+*

0.19

−0.92

1.38

0.14

 

O*+H2O*→2OH*

0.28

0.17

0.40

0.06

H2O* formation

OH*+H*→H2O*+*

0.38

−0.68

0.56

0.01

H2O* desorption

H2O*→H2O+*

/

−0.20

/

0.17

  1. *The Gibbs free energy changes of H2 and O2 adsorption and H2O desorption were calculated including the corresponding gas-phase entropy contributions under the standard state pressure and temperature. Calculated hydrogen oxidation reaction barriers and derived Gibbs free energy changes of the elementary reaction steps at anatase Pt8O8/TiO2(001) and Pt12/TiO2(001) surfaces.
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