Adsorbate formation during the electrochemical reduction of carbon dioxide at palladium—A DEMS study

✍ Scribed by D. Kolbe; W. Vielstich

• Publisher: Elsevier Science
• Year: 1996
• Tongue: English
• Weight: 325 KB
• Volume: 41
• Category: Article
• ISSN: 0013-4686
• DOI: 10.1016/0013-4686(96)00032-1

✦ Synopsis

Electrochemical reduction of carbon dioxide is followed via cyclic voltammetry (cv) and on-line mass spectrometry (DEMS) at sputtered palladium in aqueous 0.1 M KHCO, solution. Carbon monoxide is detected as a volatile reduction product at potentials more negative than -1.4 V vs. Ag/AgCl. During the first potential scan consumption of carbon dioxide is already observed at -1 V vs. Ag/AgCl corresponding to a cathodic signal in cu. Flow cell experiments show that an adsorbate is formed at -1 V. Carbon monoxide is generated from this adsorbate between -1.4 and -1.9 V. Oxidation of the adsorbate forming carbon dioxide is observed between 0.2 and 0.6 V. At -1 V adsorbed CO/COOH is likely to be formed from carbon dioxide, inhibiting further CO, reduction. Reduction of CO, proceeds after desorption of the adsorbate at potentials below -1.4V vs. Ag/AgCI.