Specular reflectivity studies of the adsorption and the oxidation of methanol on palladium in an alkaline solution

✍ Scribed by Tsutomu Takamura; Yuichi Sato

• Publisher: Elsevier Science
• Year: 1974
• Tongue: English
• Weight: 568 KB
• Volume: 19
• Category: Article
• ISSN: 0013-4686
• DOI: 10.1016/0013-4686(74)85057-7

✦ Synopsis

Adsorption and anodic oxidation of methanol on palladium electrode in Q5 N NaOH was studied by measuring current-potential (i-E) and reflectivity-potential

curves. Presence of methanol retarded the formation of the oxide layer of Pd, giving rise to an anodic shift of the potential. A linear relation was found between the potential retarded and the logarithm of methanol concentration, the slope being about 30 mV/decade. The form of adsorbed entities was discussed based on the slope. The cathodic charge consumed by the reduction of Pd-oxide was smaller in the presence of methanol than in the absence. This was explained by three causes; the less amount of oxide layer formed during the anodic sweep owing to the adsorption of oxidation product of methanol, the reduction of formed oxide layer by a chemical reaction with methanol, and a compensation effect due to the anodic oxidation of methanol during the cathodic sweep. Plottings of the total charge in the anodic region US -AR/R,, in the absence and the presence of methanol suggested that electro-oxidation of methanol proceeds only at the bare portion of Pd.