Mechanisms of the Electrochemistry of Small Organic Molecules. Low Temperature Methane Activation. Final Report (for the Period March 1, 1989-March 1, 1990)

摘要

Methane gas, dissolved in aqueous electrolyte, was found to react with dissolved oxygen at room temperature by an electrochemical mechanism. The O2 was activated by electrochemical injection of electrons to form the radical anion. The methane, in turn, was activated by reaction with the radical anion in a concerted step including the electrode surface. The major products of the reaction were CH2O and CH3OH. Much smaller amounts of CO and CO2 were also formed. The conversion of methane to CH2O and CH3OH was measured to be about 75%. CO and CO2 comprised only 1% of the product. It is assumed that the reaction is aided by the known, very long lifetime of the radical anion in alkaline solution. The lifetime has been measured to be hundreds of seconds in 0.1 mM concentration. The protonated form of the radical, O2H, has orders of magnitude shorter lifetime and may not be reactive toward CH4.