EQCM and in-situ reflectance FTIR spectroscopic studies of adsorption and oxidation of methanol on Pt electrode in alkaline media

The adsorption and oxidation of methanol on Pt electrode in alkaline media have been investigated by using cyclic voltammetry, electrochemical quartz crystal microbalance (EQCM) and in-situ reflectance FTIR spectroscopy. The experimental results demonstrated that the electrooxidation of CH3OH was closely relative to solution acidity. Only one current peak of methanol oxidation in PGPS was detected at -0.09 V, which illustrated the disappearance of the second current peak due to Pt electrode passivation in alkaline media. The magnitude of the dissociative adsorbate of methanol in alkaline media is smaller than that in acidic media. The main product, such as CO2 and CO32-, was detected clearly and the reactive intermediates that were determined by FTIRS under experimental condition might be mainly HCOO- species. The EQCM studies provide quantitative results of surface mass changes during methanol oxidation, and have thrown new light in the elucidating methanol oxidation

The adsorption and oxidation of isopropanol at platinum electrode in alkaline media

The adsorption and oxidation of isopropanol in alkaline media at platinum electrode have been investigated by using electrochemical quartz crystal microbalance (EQCM) and in situ FTIR spectroscopy. The results show that there is no self-poisoning in the electrooxidation of isopropanol in alkaline media. Though no poison species, such as CO, are evidenced by in situ FTIR spectroscopy, the adsorption of isopropanol or its dissociative products on Pt surface is suggested by EQCM data. The final product of isopropanol oxidation is only acetone under experimental condition, which suggests that the oxidation of isopropanol into acetone takes place via dehydrogenation step. The EQCM studies provide quantitative results of surface mass variation and have thrown new light in the elucidating isopropanol oxidation