In-situ NMR Study of Hydrothermal Reactions of Hazardous Chlorinated Organic Compounds: CH2Cl2 (INTERFACE SCIENCE-Solutions and Interfaces)

Abstract

Hydrothermal decomposition of a hazardous chlorinated organic compound, dichloromethane, has been investigated using in-situ NMR spectroscopy. It is found that the hydrolysis of dichloromethane yields methanediol as an intermediate. Methanediol is a hydrated form of formaldehyde and easily transformed into methanol and formic acid under basic conditions. In the temperature range of 70-140 °C, the Cannizzaro-type reaction occurs: methanediol produces the reduced form, methanol and the oxydized form, formic acid. At higher temperatures between 200 and 250 °C, on the other hand, two methanediol molecules form glycolic acid which has a new C-C bond. The reaction rate constants and activation energies for the dechlorination and the Cannizzaro-type reactions have been obtained.