Thermodynamic characterization of two layers of CO2 on a graphite surface

We find by examination of density profiles that carbon dioxide adsorbs on graphite in two distinct layers. We report the activity coefficient, entropy and enthalpy for CO2 in each layer using a convenient computational method, the Small System Method, thereby extending this method to surfaces. This opens up the possibility to study thermodynamic properties for a wide range of surface phenomena. (C) 2014 The Authors. Published by Elsevier B.V.