To create phase diagrams, we consider the different adsorption types as different surface species and we assume that the different surface species can form a homogeneous mixture on the surface, i.e., a 2D analogue of an ideal solution. A distinct surface one-phase region was assumed to be the region where a certain set of surface species are present at significant amounts, arbitrarily set to at least 1 % of all surface species. The equilibrium amounts of each surface species was obtained from minimization of the systems Gibbs free energy at different combinations of temperature, total pressure, and initial composition.