1. CO vs. CH4 oxidation over the
Pt201 Cluster.
Corneliu Buda,1 Matthew Neurock,1 Cathy Chin2 and Enrique Iglesia2
1 Department of Chemical Engineering, University of Virginia, Charlottesville, VA.
2 Department of Chemical Engineering, University of California, Berkeley, CA.
June 30th 2009

2. Pt 111 surface CO* + O*  CO2 TS Product Reactant 0 eV 0.75 eV
O Ads. En. = eV

3. Pt 100 surface CO* + O*  CO2 TS Reactant Product 0.50 eV - 0.10 eV
O Ads. En. = eV

4. CH4 vs. CO oxidation in vicinity of O*

5. CH4 1st step oxidation near O* on Pt201 cluster
Edge
Terrace
Corner
1.21 eV
1.24 eV
1.23 eV
O Ads. En. = eV
O Ads. En. = eV
O Ads. En. = eV

6. CO oxidation near O* on Pt201 cluster
Corner
Edge
Terrace
0.70 eV
0.85 eV
0.85 eV
???
O Ads. En. = eV
O Ads. En. = eV
O Ads. En. = eV

7. Corner & 100 facet
0 eV
0 eV
1.41 eV
2.29 eV

8. O locations CO locations
1, 2, 3 – (111) fcc
4, – (111) hcp
6, – (100) bridge
1 - 5 – activated by O* in 111 facet
6, 7 – activated by O* in 100 facet

9. CO Oxidation Summary
O location/Ads. En CO location/Ads. En Ea React. En.
1 / /
5 / / IP
2 / /
2 / / IP
4 / / IP
3 / /
3 / / IP
6 / /
7 / / IP
IP = In Progress

10. Comparison of the Intrinsic CO Oxidation and Methane Activation Barriers vs. O*

11. Comparison of the Apparent CO Oxidation and Methane Activation Barriers vs. O*

12. O diffusion

13. O2 diffusion on 7O surface
Ea = 0.81 eV 1σ
RE = eV

14. O2 diffusion on 7O surface
In Progress 1σ
RE = 0.10 eV

15. O2 diffusion on 5O surface1σ
0.21 eV eV

16. O2 diffusion on 3O surface1σ
0.02 eV eV

17. O2 diffusion on 3O surface2σ eV

18. O2 1σ adsorption

19. O2 1Sigma Adsorption over Pt201eV
Pt-O-O = º

20. O2 1Sigma Adsorption over Pt201-(CO)6eV
Pt-O-O = º