The chemical industry would be transformed if selective oxidation of hydrocarbons could be achieved efficiently using cheap and clean oxygen from the air. Doing that with gold as a catalyst is a method gaining in allure. The selective oxidation of hydrocarbons — the targeted addition of oxygen atoms to produce specific desired reaction products — is crucial in industrial petroleum-based chemical processes. Oxygen-containing organic compounds, such as epoxides, ketones, aldehydes, alcohols and acids, are used to produce plastics, detergents, paints, cosmetics and food additives. Oxidation catalysts are second in usage only to polymerization catalysts, accounting for 18% of total catalyst use in the United States in 1991, for example. The advancement by Hutchings and colleagues of greener' methods for oxidation catalysis using gold (page 1132 of this issue) is therefore invaluable. Most industrial oxidation processes involve more than two reaction stages, and tend to use either chlorine or organicperoxides. In the first case, chlorinated organic intermediates are neutralized to form organic oxygenates, producing huge amounts of chloride salts and lesser, but significant, amounts of toxic chlorinated organic by-products. The alternative use of organic peroxides is expensive, and is also accompanied by the formation of by-products — economically disadvantageous if there is no market for them.
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