Chemisorption and oxidation of methanol at polycrystalline Pt in acid solutions

✍ Scribed by C. Paul Wilde; Meijie Zhang

• Publisher: Elsevier Science
• Year: 1994
• Tongue: English
• Weight: 801 KB
• Volume: 39
• Category: Article
• ISSN: 0013-4686
• DOI: 10.1016/0013-4686(94)80073-1

✦ Synopsis

The oxidation of methanol has been studled over a wde range of concentrations using the electrochemical quartz crystal nucrobalance (EQCM) techmque Accumulation of strongly adsorbing spectes at the electrode surface IS accompamed by a decrease m mass, relative to the background electrolyte, and the rate of this mcrease IS an m&cation of how rapidly the surface becomes covered by adsorbates At lower methanol concentrattons, removal of these adsorbates IS accompamed by a stepped mcrease m the mass response and 1s followed by a small regon of potential where the mass IS constant and where methanol 1s apparently oxldmzd by a reamon wth OH at the electrode surface There 1s some adsorption m this regon too, which increases wth mcreasmg methanol concentration At 30mM methanol and above, the step upon adsorbate removal and the subsequent remon of constant mass can no longer be distmgmshed Mass responses also reveal that mcreasmg amounts of methanol m the electrolyte cause a shting of the oxldative removal of strongly adsorbed mtermedlates to more positive potentials, a sigmficant mhWlon of the irreversible oxldatlon of the electrode surface and a more rapid removal of the oxide on the cathodic scan Key words electrochermcal quartz crystal mmobalance, methanol