Photoassisted catalytic oxidation of alcohols and halogenated hydrocarbons with amorphous manganese oxides

This manuscript discusses the synthesis of Amorphous Manganese Oxide (AMO) materials that are used for efficient photoassisted catalytic oxidation of alcohols and halogenated hydrocarbons. Characterization studies suggest that oxygen is lost from AMO very readily under illumination, creating oxygen vacancies that may be important in photooxidation reactions. Alcohols are converted to ketones such as acetone from isopropanol with 100% selectivity at room temperature. These AMO systems have turnover numbers that are over one order of magnitude greater than TiO2 systems for isopropanol oxidation and over an order of magnitude greater than for TiO2 systems in decomposition of halogenated hydrocarbons. In addition the TiO2 systems are poisoned much faster than the AMO materials, especially in degradation of halogenated hydrocarbons. The same high activity and selectivity occur for the total oxidation of halogenated hydrocarbons such as methyl bromide which is converted into CO2, H2O and Br-2. The synthesis, characterization, and photoactivity of these materials will be discussed. AMO photocatalysts are also active in the decomposition of methyl choride and methyl iodide.