A quantitative theoretical analysis of the enthaplic effects accompanying ion adsorption at the oxide/electrolyte interface, based on a model of energetically heterogeneous surface oxygens, is presented. The
triple layer complexation model is accepted, along with the 2-pK charging mechanism. For the purpose
of illustration a set of experimental data is subjected to that quantitative analysis including titration
curves, radiometrically measured individual iostherms of ions, and calorimetric titration data for the
alumina/NaCl electrolyte system. Two models of energetic heterogeneity were taken into consideration.
One of them assumes that the binding-to-oxygen energies of the surface complexes vary but are highly
correlated when going from one to another surface oxygen. The other model of surface heterogeneity
assumes that these correlations are very small. Our numerical simultaneous analysis of the titration data,
of the individual isotherms of Na+ and Cl- adsorption, and of the accompanying heat effects advocates
strongly for the model of surface heterogeneity assuming small correlations to exist. A good simultaneous
fit of all three kinds of experimental data is obtained, with a small uncertainty as for the values of the
estimated adsorption parameters. A simultaneous fit of the measured enthalpic effects appears to be an
especially strong criterion for a proper choice of adsorption parameters.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.