Voltammetric behaviour of ammonia at gold and vitreous carbon rotating-disc electrodes in molten alkali nitrates

Abstract

In the course of a systematic investigation of the electroactivity of hydrogen–nitrogen compounds in molten alkali nitrates, experiments using gold and vitreous carbon rotating-disc electrodes have been performed in solutions containing NH₃ and NH₃+ H₂O.

The results collected with gold electrodes confirm the validity of the mechanistic model previously proposed for platinum; in fact no substantial difference is observed between voltammograms recorded for the two noble metals: relatively small shifts observed between the various current–potential curves can be ascribed to different discharge overvoltages of NH₃ and/or H₂O on the two electrode materials.

Partially contrasting results were obtained on vitreous carbon electrodes, leading to the formulation of a new electrode-mechanistic model.