Mineral surfaces expose reactive sites acting as reaction centers for gases, solutes and solvents. In particular, (hydr)oxo groups are sites of especial importance from Earth subsurface to atmospheric processes where they can undergo (de)protonation as well as ligand exchange reactions, and form extensive networks of hydrogen bonds between themselves and interfacial species and solvents. Knowledge of the types, and distributions of these groups is essential for understanding molecular-scale processes taking place at mineral surfaces.<br/><br/>Vibration spectroscopic signatures of mineral surfaces provides insight into the identity and reactivity of hydroxo groups. In this work initial efforts from our made on resolving these processes in synthetic iron oxyhydroxides of controlled crystal habits will first be reviewed. More recent findings on the identity and reactivity of analogous sites in less well defined minerals, including hematite, ferrihydrite and montmorillonite particles will thereafter be presented. Examples of ligand exchange reactions and thin water film formation will be used to show how site-specific, and in some cases crystal face-specific, reactions can be readily tracked and used to devise molecularly sound reaction mechanisms that can be readily bridged to molecular simulations.

Tracking site-specific reactions at mineral surfaces

253rd National Meeting (2017)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.