Naslov
Evaluation of Enthalpy of Interfacial Reactions from Temperature Dependency of Interfacial Equilibrium

Autori
Kallay, Nikola ; Čop, Ana

Izvornik
Applied Surface Science (0169-4332) 252 (2005), 3; 745-751

Vrsta, podvrsta i kategorija rada
Radovi u časopisima, članak, znanstveni

Ključne riječi
surface potential; enthalpy of surface protonation; electrostatic effects at interface; interfacial equilibrium; interfacial thermodynamics

Sažetak
Temperature dependency of equilibrium at metal oxide - aqueous electrolyte solution interface was analyzed by numerical simulation. Derivations of inner surface potential with respect to temperature were performed at constant values of several different parameters. When surface charge density in inner plane was kept constant the reasonable results were obtained, i.e. the electrostatic contribution to enthalpy of protonation of amphotheric surface sites was found to be positive in the pH region below the point of zero potential and negative above this point. All other examined possibilities produced opposite results. Derivation of empirical interfacial equilibrium constant at constant surface potential indicated that electrostatic effect on protonation entropy is negligible and that electrostatic contributions to reaction Gibbs energy and enthalpy are equal and directly related to the surface potential in the inner plane.

Izvorni jezik
Engleski

Znanstvena područja
Kemija

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