Theoretical study of pattern formation during the catalytic oxidation of CO on Pt{100} at low pressures.

Theoretical studies have thus far been unable to model pattern formation during the reaction in this system on physically feasible length and time scales. In this paper, we derive a computational reaction-diffusion model for this system in which most of the input parameters have been determined experimentally. We model the surface on a mesoscopic scale intermediate between the microscopic size of CO islands and the macroscopic length scale of pattern formation.

Pattern formation during the oxidation of CO on Pt{100}: a mesoscopic model.

Constantly changing irregular patterns of carbon monoxide (CO) and oxygen are seen during CO oxidation on platinum crystals in the [100] orientation. Ours is the first reaction-diffusion model to reproduce this pattern formation on physically feasible length and time scales, faithfully incorporating the available experimental data. Numerical simulations show patterns made up of CO and oxygen fronts moving at similar speeds to those seen in experiments.

Theory of C2Hx species on Pt{110}(1x2): structure, stability, and thermal chemistry.

The adsorption of C2Hx (x=0-5) hydrocarbon fragments on Pt{110}(1x2) has been investigated using calculations based on density functional theory. For all the species, the most stable adsorption site identified completes the tetravalency of each carbon atom and involves the maximum possible number of Pt atoms subject to that constraint. The most stable adsorption sites for C2Hx fragments of stoichiometry x=2-5 involve ridge atoms, while trough sites stabilize C2H and C2 species.