Mass spectrometric investigation of the electrochemical behavior of adsorbed carbon monoxide at platinum in 0.2 M sulphuric acid

The technique of Electrochemical Mass Spectrometry is applied to the cathodic adsorption of CO at platinum in 0.2 M H₂SO₄ and the anodic desorption of the reaction product CO₂. From the data obtained by CO shielding during the adsorption reaction and by CO₂ collection during the desorption process, one site adsorption of the principal CO adsorbate at the electrode surface is determined to occur over the whole range of CO coverage. A two electron transfer is involved in the oxidation of this adsorbed CO species to CO₂. CO adsorbed in the hydrogen adsorption region produces a small amount of adsorbate requiring a three electron transfer to produce CO₂.