Energetic and vibrational properties of carbon monoxide adsorption on platinum nanoparticles under applied voltage*

Carbon monoxide poisoning is a significant limitation to the performance of platinum-based transition metals. Manipulating the size of the catalytic particles could help inhibit carbon monoxide adsorption and increase the life cycle of the catalyst. This study models the energetic and vibrational properties of carbon monoxide on platinum nanoparticles under applied voltage using the self-consistent continuum solvation (SCCS) model. We determine adsorption patterns as the function of nanoparticle size and site coordination. It is found that the local surface charge strongly affects carbon monoxide adsorption particularly along the (111) and (001) facets of the nanoparticle. These results could prove useful in optimizing electrocatalytic systems such as proton exchange membrane (PEM) fuel cells where trace amounts of carbon monoxide in the hydrogen fuel can poison the nanostructured platinum electrodes and decrease the durability of the fuel cell.