An in situ weighing study of the mechanism for the formation of the adsorbed oxygen monolayer at a gold electrode

Abstract

The mechanism for the formation of the first monolayer of electrosorbed oxygen at a gold electrode was shown to proceed via the three step reaction sequence: (a) Au-(H 2O) ads → Au-OH+H ++ e −. (2) Au-OH → Au=O+H ++ e −, and finally the place exchange reaction (3) Au=O+H 2O → O=Au-(H 2O) ads in which a water molecule adsorbs on the gold atom. The mechanism was established by determining the in situ change in weight of the gold electrode concomitantly with the cyclic voltammogram using the oscillating quartz crystal method.