| AVS 55th International Symposium & Exhibition | |
| Surface Science | Monday Sessions |
| Session SS+NC-MoM |
| Session: | Catalysis and Alloy Formation |
| Presenter: | F. Tao, Lawrence Berkeley National Laboratory |
| Authors: | F. Tao, Lawrence Berkeley National Laboratory Z. Liu, Lawrence Berkeley National Laboratory C.Y. Chung, Lawrence Berkeley National Laboratory D. Butcher, Lawrence Berkeley National Laboratory Y.W. Zhang, Lawrence Berkeley National Laboratory M. Grass, Lawrence Berkeley National Laboratory M. Salmeron, Lawrence Berkeley National Laboratory G.A. Somorjai, Lawrence Berkeley National Laboratory |
| Correspondent: | Click to Email |
Bridging pressure gap of catalytic model studies is one of the most changeling issues to be addressed for elucidating mechanism of heterogeneous catalysis. A new high pressure STM was homebuilt for this purpose. CO adsorption and oxidation on a stepped platinum single crystal was selected as a model to study in a wide range of CO pressure from 10-9 to 1000 Torr as the adsorption and surface structure of CO on noble metals under a realistic catalytic condition is an important topic for pollution control. STM study revealed a significant pressure dependence of surface structure of CO adsorption. The clean platinum single crystal surface prepared in UHV progressively reconstruct by adsorbing CO at step sites and breaking the step edge at low pressure. At high pressure the surface reconstructs into clusters with a size of 1-3 nm. The dramatic structural evolution from low pressure to high pressure is reversible. The reversibility is confirmed with a synchrotron-based high pressure XPS. A model rationalizing the pressure dependence of CO adsorption on this catalyst is suggested.