Constants of acid-base equilibria at the ZrO2/electrolyte interface

Acid-base equilibria arising at the zirconium oxide/electrolyte interface were studied experimentally using potentiometric titration and analysis of the dependence of the electrokinetic potential on the pH value in aqueous solutions of potassium chloride of various concentrations. The equilibrium constants were calculated. It was found that the two methods give consistent values of acid-base equilibrium constants: pK0 1 = 4.0, pK0 2 = 9.2, pK0 3 = 6.2, and pK0 4 = 6.7.