Abstract
In this work ethanol oxidation on carbon supported Pt catalysts modified with irreversibly adsorbed adatoms is reported. This study concerns understanding of the effect of a second metal on real catalysts in conditions as close as possible to those applied in fuel cells systems. The results were acquired using cyclic voltammetry, chronoamperometry and in situ infra-red techniques always taking into account the future application of the electrocatalyst materials in fuel cells. Foreign adatoms, both Bi and Sb, irreversibly adsorbed on a Pt electrode were studied, and revealed to enhance catalytic activity toward a more efficient ethanol oxidation. The catalytic enhancement continuously increased with the coverage of the adatom on the surface up to coverages close to saturation. With these high coverages a decrease of the activity was observed suggesting that free platinum atoms are required to oxidize ethanol. The results suggest that the adatoms play a third body role avoiding the poisoning of the Pt sites that will then be free for oxidizing ethanol. However, electronic effects on Pt/C-Bi and bifunctional mechanism at Pt/C-Sb are also suggested. The oxidation products were identified by in situ FTIR and are mainly acetaldehyde and acetic acid for the three catalysts. CO2 was also observed for the unmodified Pt/C and interestingly for the Pt/C-Sb electrodes.
| Original language | English |
|---|---|
| Pages (from-to) | 378-385 |
| Number of pages | 8 |
| Journal | Applied Catalysis. B, Environmental |
| Volume | 140-141 |
| DOIs | |
| Publication status | Published - 1 Aug 2013 |
| Externally published | Yes |
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Keywords
- Adatoms
- Direct ethanol fuel cells (DEFCs)
- Electrocatalysis
- Ethanol oxidation
- Platinum
Cite this
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Tailoring properties of platinum supported catalysts by irreversible adsorbed adatoms toward ethanol oxidation for direct ethanol fuel cells. / Figueiredo, Marta C.; Santasalo-Aarnio, Annukka; Vidal-Iglesias, Francisco J.; Solla-Gullón, José; Feliu, Juan M.; Kontturi, Kyosti; Kallio, Tanja (Corresponding author).
In: Applied Catalysis. B, Environmental, Vol. 140-141, 01.08.2013, p. 378-385.Research output: Contribution to journal › Article › Academic › peer-review
TY - JOUR
T1 - Tailoring properties of platinum supported catalysts by irreversible adsorbed adatoms toward ethanol oxidation for direct ethanol fuel cells
AU - Figueiredo, Marta C.
AU - Santasalo-Aarnio, Annukka
AU - Vidal-Iglesias, Francisco J.
AU - Solla-Gullón, José
AU - Feliu, Juan M.
AU - Kontturi, Kyosti
AU - Kallio, Tanja
PY - 2013/8/1
Y1 - 2013/8/1
N2 - In this work ethanol oxidation on carbon supported Pt catalysts modified with irreversibly adsorbed adatoms is reported. This study concerns understanding of the effect of a second metal on real catalysts in conditions as close as possible to those applied in fuel cells systems. The results were acquired using cyclic voltammetry, chronoamperometry and in situ infra-red techniques always taking into account the future application of the electrocatalyst materials in fuel cells. Foreign adatoms, both Bi and Sb, irreversibly adsorbed on a Pt electrode were studied, and revealed to enhance catalytic activity toward a more efficient ethanol oxidation. The catalytic enhancement continuously increased with the coverage of the adatom on the surface up to coverages close to saturation. With these high coverages a decrease of the activity was observed suggesting that free platinum atoms are required to oxidize ethanol. The results suggest that the adatoms play a third body role avoiding the poisoning of the Pt sites that will then be free for oxidizing ethanol. However, electronic effects on Pt/C-Bi and bifunctional mechanism at Pt/C-Sb are also suggested. The oxidation products were identified by in situ FTIR and are mainly acetaldehyde and acetic acid for the three catalysts. CO2 was also observed for the unmodified Pt/C and interestingly for the Pt/C-Sb electrodes.
AB - In this work ethanol oxidation on carbon supported Pt catalysts modified with irreversibly adsorbed adatoms is reported. This study concerns understanding of the effect of a second metal on real catalysts in conditions as close as possible to those applied in fuel cells systems. The results were acquired using cyclic voltammetry, chronoamperometry and in situ infra-red techniques always taking into account the future application of the electrocatalyst materials in fuel cells. Foreign adatoms, both Bi and Sb, irreversibly adsorbed on a Pt electrode were studied, and revealed to enhance catalytic activity toward a more efficient ethanol oxidation. The catalytic enhancement continuously increased with the coverage of the adatom on the surface up to coverages close to saturation. With these high coverages a decrease of the activity was observed suggesting that free platinum atoms are required to oxidize ethanol. The results suggest that the adatoms play a third body role avoiding the poisoning of the Pt sites that will then be free for oxidizing ethanol. However, electronic effects on Pt/C-Bi and bifunctional mechanism at Pt/C-Sb are also suggested. The oxidation products were identified by in situ FTIR and are mainly acetaldehyde and acetic acid for the three catalysts. CO2 was also observed for the unmodified Pt/C and interestingly for the Pt/C-Sb electrodes.
KW - Adatoms
KW - Direct ethanol fuel cells (DEFCs)
KW - Electrocatalysis
KW - Ethanol oxidation
KW - Platinum
UR - http://www.scopus.com/inward/record.url?scp=84877886547&partnerID=8YFLogxK
U2 - 10.1016/j.apcatb.2013.04.038
DO - 10.1016/j.apcatb.2013.04.038
M3 - Article
AN - SCOPUS:84877886547
VL - 140-141
SP - 378
EP - 385
JO - Applied Catalysis. B, Environmental
JF - Applied Catalysis. B, Environmental
SN - 0926-3373
ER -