E. N. Schulman and P. S. Weiss
Submitted for publication.
Abstract
The presence of a sticky step edge alters the collision rates of adsorbates and may locally change the energy barrier in Langmuir-Hinshelwood reactions. We present an analytic comparison between two systems, a standard terraced surface and another with the addition of a sticky step edge that attracts one of the adsorbates in a bi-molecular reaction. The step edge reduces the interspecies collision rate, thus impeding the catalytic process, but may compensate by reducing the energy needed for the reaction. We further address the extent to which the alignment of adsorbed reactants by substrate-mediated interactions can enhance the reaction rate.