Surface-mediated reactions, diversity

The diversity of reactions that are considered to be surface mediated has also increased over the past decade. It is not only strict sorption/desorption and precipitation/dissolution processes that are important but also the surface mediation of reactions such as electron transfer (eg. 14-17), hydrolysis 18) and various photochemical transformations. In addition certain solid phases, in particular metallic iron, iron oxides and smectitic clays, are capable of transferring electrons in and out of their bulk structure (eg. 19-23), When viewed in this context, minerals should not be considered as passive solids, or even as simple sources of a reactive surface but must be considered as bulk reactants. 

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