AVS 45th International Symposium
    Surface Science Division Monday Sessions
       Session SS2-MoM

Paper SS2-MoM3
The Role of Steps and Kinks in Catalytic Activity

Monday, November 2, 1998, 9:00 am, Room 309

Session: Molecular Adsorbates on Metals
Presenter: L. Ford, University of Illinois, Urbana
Authors: L. Ford, University of Illinois, Urbana
P. Blowers, University of Illinois, Urbana
R. Masel, University of Illinois, Urbana
Correspondent: Click to Email
In the literature, there is the idea that steps and kinks are active sites for chemical reactions, but the experimental data is far from convincing. In this paper we see if there is a correlation between step and kink density and reactivity for a number of simple decomposition and hydrogenation reactions on platinum. We have examined the decomposition of ethylene, methanol, methylamine, ethanol, propanol, NO, the hydrogenation of ethylene, and the hydrogenolysis of ethylene, methanol, ethanol on Pt(111), Pt(110)(1x1), Pt(110)(1x2), Pt(100)-hex, Pt(100)(1x1), Pt(210), Pt(511), Pt(331). We find that in general stepped surfaces have different reactivity than closed packed planes, but some stepped surfaces are more active than Pt(111) while other stepped surfaces are less active than Pt(111). There is no correlation between step and kink density and catalytic activity. Calculations are done to understand the variations. We find that in general stepped surfaces relax to more stable geometries. The relaxation process lowers the electronic coordination number of the atoms in the surface of the catalyst so after relaxation, there is not a large difference in the coordination of atoms in stepped surfaces and Pt(111).