Geochemistry of Mineral Surfaces and Factors Affecting Their Chemical Reactivity

Geochemistry of Mineral Surfaces and Factors Affecting Their Chemical Reactivity 

Gordon E. Brown, Jr.1,2 Thomas P. Trainor3 and Anne M. Chaka4 

From this general description of the Earth s solid-fluid-gaseous envelope, it is apparent that reactions governing the chemistry of the environment are dominated by those at environmental interfaces. The importance of such reactions is well summarized in a 1987 quotation from the late Werner Stumm [3] Almost all of the problems associated with understanding the processes that control the composition of our environment concern interfaces, above all the interfaces of water with naturally occurring solids.  

Mineral-liquid or mineral-gas interfaces under reactive conditions cannot be studied easily using standard UHV surface science methods. To overcome the pressure gap between ex situ UHV measurements and the in situ reactivity of surfaces under atmospheric pressure or in contact with a liquid, new approaches are required, some of which have only been introduced in the last 20 years, including scanning tunneling microscopy [28,29], atomic force microscopy [30,31], non-linear optical methods [32,33], synchrotron-based surface scattering [34—38], synchrotron-based X-ray absorption fine structure spectroscopy [39,40], X-ray standing wave 

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Geochemistry of Mineral Surfaces and Factors Affecting Their Chemical Reactivity Table 7.4 (Continued)... 

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