The Chemistry of Water on Alumina Surfaces: Reaction Dynamics from First Principles

• DOI: 10.1126/science.282.5387.265
• Publication Date: 2002-07-27T09:43:20Z
• Authors: Kenneth C. Hass; William F. Schneider; Alessandro Curioni; Wanda Andreoni
• Keywords: Self-ionization of water; Metastability

Aluminas and their surface chemistry play a vital role in many areas of modern technology. The behavior adsorbed water is particularly important poorly understood. Simulations hydrated alpha-alumina (0001) surfaces with ab initio molecular dynamics elucidate aspects this problem, especially the complex dissociation related reactions. At low coverage, free energy profiles established that molecularly metastable dissociates readily, even absence defects, by kinetically preferred pathway. Observations at higher coverage revealed rapid unanticipated collective effects, including water-catalyzed proton transfer reactions between hydroxide. results provide consistent interpretation measured dependence heats adsorption, hydroxyl vibrational spectra, other experiments.