SOLVENT EFFECTS ON STANDARD THERMODYNAMIC FUNCTIONS OF SURFACE DISSOCIATION OF OXIDES

Different definitions of standard thermodynamic functions of proton ad sorption on oxides are discussed in terms of distinguishing between th e temperature variations of acidity of the surface and those of pK(w). Inert electrolyte titration was proposed as an accurate method for th e determination of pH(o) of oxides. The temperature dependence of pH(o ) of gamma-alumina was similar to other oxides notwithstanding some li terature data (Akratopulu et al. 1986). The standard enthalpy of proto n adsorption on gamma-alumina is more sensitive to dioxane admixtures in water relative to methanol. (C) 1994 Academic Press, Inc.