Better Understanding of Water's Reaction with Metal Oxides
Metal oxides are very common materials on Earth, as is water, yet the interactions between them are not well understood. We do know enough to use metal oxides as catalysts for reactions involving water, but exactly what happens is not completely known. Researchers at the University of Wisconsin, Madison however have recently made a discovery that should shed some light on the mechanisms though.
It is somewhat easy to understand how water interacts with metals, as metals can be very homogenous. Once oxygen is added though, defects can be present in the oxide layer and affect the chemical processes by allowing hydroxyls to form. Using scanning tunneling microscopy and some quantum mechanics, the researchers were able to identify the chemical structures and atoms at the defect sites. The results indicate that when the metal oxide surface is smooth and free of defects, amorphous networks of water molecules form, but when there are defects and hydroxyls, the water molecules take on a more ordered structure.
The next step is to learn how these water structures interact with other materials, and that could lead to better metal-oxide catalysts. It could also lead to advances in geochemistry and atmospheric chemistry, wherever similar processes occur.
Source: University of Wisconsin, Madison