ELECTROCHEMICAL REDUCTION OF DICHLOROMETHANE TO HIGHER HYDROCARBONS

The electroreduction of CH2Cl2 at Ni, Cu, Pt and Ag electrodes in acet onitrile and (C4H9)(4)NI 0.1 M as supporting electrolyte was studied. The half-wave potential was found to be in the range -2.2 to -2.5 V vs SCE at room temperature. From the analysis of the gaseous products it was found that methane, ethylene, chloromethane, propene and butene i somers were the main products, while at silver and platinum cathodes m ethane was mainly produced. The effect of the potential on the current efficiency of the gaseous products was also studied. The current effi ciency of the products increases at concentration levels of CH2Cl2 up to 0.2 M, whereas at higher values its CE is not significantly influen ced. The application of the Schultz-Flory distribution analysis to the experimental data showed that the hydrocarbons are mainly formed via polymerization of methylene radicals on the surface of Ni and Cu elect rodes. At Ag and Pt electrodes the mechanism appears to be different.