On Modeling Proton Affinity at the Oxide/Water Interface

✍ Scribed by William F. Bleam

• Publisher: Elsevier Science
• Year: 1993
• Tongue: English
• Weight: 379 KB
• Volume: 159
• Category: Article
• ISSN: 0021-9797
• DOI: 10.1006/jcis.1993.1328

✦ Synopsis

The electrostatic model predicts the point of zero net proton change of oxide/water interfaces from independent variables having the form: (s / R) ( (s) is the bond valence, cation valence divided by coordination number, and (R) is the distance separating two ions). The electrostatic model uses bond valence (s) to represent the effective charge at a surface site. For each of the various electrostatic models, there is an analogous crystallochemical model that is identical in every way except that it lacks (R^{-1}) dependence. A statistical comparison of the electrostatic and crystallochemical models demonstrates that the (R^{-1})-dependence in the electrostatic model makes no significant contribution to the correlation coefficient. The crystallochemical model, besides being a predictor of proton affinity, has close connections with the bond-valence model of hydrogen-bond structure and function. From this connection, the crystallochemical model makes qualitative predictions regarding the effect of hydrogen bonding on: (a) proton affinity; (b) the physisorption of water; and (c) surface structure. 1993 Academic Press. Inc.