In this work, the effect of temperature on the adsorption states of Pt(111) vicinal surface electrodes in perchloric acid is studied through a thermodynamic analysis. The method allows calculating thermodynamic properties of the interface. In this framework, the concept of the generalized isothermand the statistical thermodynamics description are applied to calculate formal entropies, enthalpies and Gibbs energies,ΔGi0, of the adsorption processes at two-dimensional terraces and one-dimensional steps. These values are compared with data from literature. Additionally, the effect of the step density onΔGi0 and on the lateral interactions between adsorbed species,ωij, at terraces and steps is also determined. Calculated ΔGi0 , entropies and enthalpies are almost temperature-independent, especially at steps, but they depend on the step orientation. In contrast,ΔGi0 and ωij at terraces depend on the step density, following a linear tendency for terrace lengths larger than 5 atoms. However, while ΔGi0 increases with the step density, ωij decreases. Results were explained by considering the modification in the energetic surface balance by hydrogen, Hads, andwater,H2Oads, co-adsorption on the electrode, which in turn determines the whole adsorption processes on terraces and steps. ; This study has been carried out in the framework of the European Commission FP7 Initial Training Network “ELCAT”, Grant Agreement No. 214936-2. Support from the Spanish MINECO though project CTQ2013-44083-P and GV through PROMETEOII/2014/013 (FEDER) are greatly acknowledged.