The three-way catalytic converter relies on cerium oxides to reduce nitrogen oxides to nitrogen gas and oxidize carbon monoxide to carbon dioxide and unburned hydrocarbons to carbon dioxide and water in the exhaust products.
At room temperature a clean metal surface will oxidize very little, since a thin oxide film forms and protects the metal from further oxidation.
Scott Fendorf and colleagues of Stanford University used laboratory experiments to show that birnessite, a manganese-oxide mineral found in these regions, could oxidize the chromium III) in chromite into chromium VI).
Moreover, it is both a strong oxidant and peroxidant and, if formed, may chemically attack (oxidize) a nearby molecule, often the same molecule that sensitized the molecular oxygen.
In this process, oxygen or air is added to the impure liquid metal; the impurities oxidize before the metal and are removed as an oxide slag or a volatile oxide gas.
The metal continues to oxidize upon prolonged contact with air, generating a heavy nonprotective oxide crust.
Because iron oxide is always present in glass, the role of CeO2 is to oxidize the Fe2+, which imparts a bluish tint to the glass, to Fe3+, which has a faint yellow colour.
In thermal oxidation the substrate is heated to 800 1,100 °C (1,500 2,000 °F), which causes the surface to oxidize.
One way the body detoxifies ethanol is to oxidize it, using an enzyme produced by the liver, alcohol dehydrogenase, or ADH.
Typically, about 5 kilograms (11 pounds) of manganese dioxide or 1.5 kilograms of sodium chlorate per ton suffice to oxidize tetravalent uranium.
When varnish dries, its solvent portion evaporates, and the remaining constituents oxidize or polymerize to form a durable transparent film.
