Research output: Contribution to journal › Article › peer-review
Model electrocatalysts for the oxidation of rechargeable electrofuels - carbon supported Pt nanoparticles prepared in UHV. / Stumm, Corinna; Kastenmeier, Maximilian; Waidhas, Fabian; Bertram, Manon; Sandbeck, Daniel J.S.; Bochmann, Sebastian; Mayrhofer, Karl J.J.; Bachmann, Julien; Cherevko, Serhiy; Brummel, Olaf; Libuda, Jörg.
In: Electrochimica Acta, Vol. 389, 138716, 01.09.2021.Research output: Contribution to journal › Article › peer-review
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TY - JOUR
T1 - Model electrocatalysts for the oxidation of rechargeable electrofuels - carbon supported Pt nanoparticles prepared in UHV
AU - Stumm, Corinna
AU - Kastenmeier, Maximilian
AU - Waidhas, Fabian
AU - Bertram, Manon
AU - Sandbeck, Daniel J.S.
AU - Bochmann, Sebastian
AU - Mayrhofer, Karl J.J.
AU - Bachmann, Julien
AU - Cherevko, Serhiy
AU - Brummel, Olaf
AU - Libuda, Jörg
N1 - Publisher Copyright: © 2021
PY - 2021/9/1
Y1 - 2021/9/1
N2 - Isopropanol (IPA) can be used as a rechargeable electrofuel. In this approach, IPA is oxidized to acetone (ACE) in a direct alcohol fuel cell and the formed ACE is subsequently back-converted to IPA in a heterogeneously catalyzed process. To study the electrochemical reaction mechanisms of the IPA oxidation at the molecular level, appropriate and well-defined model electrocatalysts are necessary. In this work we prepare such model electrocatalysts by surface science methods in ultra-high vacuum (UHV). The catalysts consist of well-defined platinum nanoparticles on carbon supports. As carbon support, we use flat highly ordered pyrolytic graphite (HOPG) and thin (20 nm) magnetron sputtered carbon films on a polycrystalline gold substrate. In a first step, we characterize the model electrocatalysts and investigate their stability in-situ with complementary methods, i.e. by electrochemical scanning tunneling microscopy (EC-STM), electrochemical on-line inductively coupled plasma mass spectrometry (ICP-MS) and CO stripping experiments followed by electrochemical infrared reflection absorption spectroscopy (EC-IRRAS). We determined a stability window ranging from -0.65 VRHE to 1.15 VRHE for both sample types, independent of the presence or absence of IPA in the electrolyte. In the second step, we study the oxidation of IPA on tPt nanoparticles using differential electrochemical mass spectrometry (DEMS) and EC-IRRAS. The onset of IPA oxidation is observed at 0.3 VRHE. ACE is formed with high selectivity, while we identify traces of CO2 as the only side-product formed at higher potentials. However, we do not observe any formation of adsorbed CO. A direct comparison of these results with previous work on Pt(111) suggests that low coordinated Pt sites and size effects play a subordinate role for IPA oxidation on Pt electrocatalysts.
AB - Isopropanol (IPA) can be used as a rechargeable electrofuel. In this approach, IPA is oxidized to acetone (ACE) in a direct alcohol fuel cell and the formed ACE is subsequently back-converted to IPA in a heterogeneously catalyzed process. To study the electrochemical reaction mechanisms of the IPA oxidation at the molecular level, appropriate and well-defined model electrocatalysts are necessary. In this work we prepare such model electrocatalysts by surface science methods in ultra-high vacuum (UHV). The catalysts consist of well-defined platinum nanoparticles on carbon supports. As carbon support, we use flat highly ordered pyrolytic graphite (HOPG) and thin (20 nm) magnetron sputtered carbon films on a polycrystalline gold substrate. In a first step, we characterize the model electrocatalysts and investigate their stability in-situ with complementary methods, i.e. by electrochemical scanning tunneling microscopy (EC-STM), electrochemical on-line inductively coupled plasma mass spectrometry (ICP-MS) and CO stripping experiments followed by electrochemical infrared reflection absorption spectroscopy (EC-IRRAS). We determined a stability window ranging from -0.65 VRHE to 1.15 VRHE for both sample types, independent of the presence or absence of IPA in the electrolyte. In the second step, we study the oxidation of IPA on tPt nanoparticles using differential electrochemical mass spectrometry (DEMS) and EC-IRRAS. The onset of IPA oxidation is observed at 0.3 VRHE. ACE is formed with high selectivity, while we identify traces of CO2 as the only side-product formed at higher potentials. However, we do not observe any formation of adsorbed CO. A direct comparison of these results with previous work on Pt(111) suggests that low coordinated Pt sites and size effects play a subordinate role for IPA oxidation on Pt electrocatalysts.
KW - 2-propanol
KW - Carbon support
KW - In-situ electrochemical methods
KW - Isopropanol oxidation
KW - Isopropyl alcohol
KW - Model catalysis
KW - Platinum nanoparticles
KW - FORMIC-ACID
KW - METHANOL
KW - PLATINUM DISSOLUTION
KW - STABILITY
KW - In-situ electrochemical methods 2-propanol
KW - ADSORPTION
KW - ISOPROPANOL OXIDATION
KW - THIN-FILM ELECTROCATALYSTS
KW - IN-SITU FTIR
KW - PARTICLE-SIZE
KW - CELL
UR - http://www.scopus.com/inward/record.url?scp=85108525198&partnerID=8YFLogxK
U2 - 10.1016/j.electacta.2021.138716
DO - 10.1016/j.electacta.2021.138716
M3 - Article
AN - SCOPUS:85108525198
VL - 389
JO - Electrochimica Acta
JF - Electrochimica Acta
SN - 0013-4686
M1 - 138716
ER -
ID: 86102051