CO oxidation and CO2 reduction on carbon supported PtWO3 catalyst

✍ Scribed by N.P. Lebedeva; V. Rosca; G.J.M. Janssen

• Publisher: Elsevier Science
• Year: 2010
• Tongue: English
• Weight: 553 KB
• Volume: 55
• Category: Article
• ISSN: 0013-4686
• DOI: 10.1016/j.electacta.2009.12.041

✦ Synopsis

The activity of a carbon supported PtWO 3 (PtWO 3 /C) catalyst in the CO oxidation and CO 2 reduction reactions was evaluated in sulfuric acid solution at room temperature.

Cyclic voltammetry combined with on-line mass spectrometry shows that the oxidation of both saturated CO adlayer and dissolved CO on PtWO 3 /C material commences at rather low potentials, ca. 0.18 and 0.12 V vs. RHE, respectively. However, the low-potential process seems to involve only a minor fraction of the CO adlayer, the major part of the adsorbed CO layer being oxidised at the potentials as high as those for pure Pt catalysts-ca. 0.7 V vs. RHE. PtWO 3 /C material was found to reversibly de-activate upon a prolonged exposure to the CO-saturated solution due to the inhibition of the hydrogen tungsten bronze formation.

The reduction of CO 2 on PtWO 3 /C leads to the formation of an adsorbate -presumably CO -on the Pt sites of the catalyst. Although the rate of the adsorbate build-up on PtWO 3 /C at 0.1 V is lower than that on pure Pt/C, our results indicate that upon a prolonged exposure of the PtWO 3 /C electrode to a CO 2 -saturated solution a complete poisoning of the Pt sites with the adsorbate is likely to occur at room temperature.