EQCM Studies of Methanol Adsorption and Oxidation

The adsorption of methanol was followed quantitatively by the combination of cyclic voltammetiy and EQCM. ° 

RHE due to the removal of the oxygenated species and of any adsorption residues from methanol. Finally the re-adsorption of methanol residues between 0.6 an 0.05 V vs. RHE lead to a mass increase Aw = 5 ng cm.  

Aity quantitative inteqjretation is still difficult to make, since the mass variations result from several coupled processes replacement of adsorbed hydrogen, water molecules and supporting anions by strongly adsorbed species from methanol chemisorption, reorganization of the double layer, formation of oxygenated species at the platinum surface, etc. 

Therefore more quantitative and selective methods are needed such as DBMS and radiotracer labehng, to investigate the adsorption and oxidation of methanol. 

Differential Electrochemical Mass Spectrometry (OEMS) was also used for methanol stripping experiments, which can give some information on the electrode coverage by species coming from the adsorption and oxidation of methanol. First, it can be seen from the CVs and the MSCVs recorded on a coreduced PtogRuo2/C catalyst as an example (Fig. 19) that the coverage of the electrode is much lower from methanol adsorption (curves 2) than that from CO adsorption (curves 1). 

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