Final published version
Research output: Contribution to Journal/Magazine › Journal article › peer-review
Research output: Contribution to Journal/Magazine › Journal article › peer-review
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TY - JOUR
T1 - Oxygen reduction on structurally well defined, bimetallic PtRu surfaces
T2 - monolayer PtxRu1-x/Ru(0001) surface alloys versus Pt film covered Ru(0001)
AU - Brimaud, S.
AU - Engstfeld, A. K.
AU - Alves, O. B.
AU - Hoster, H. E.
AU - Behm, R. J.
PY - 2014/2
Y1 - 2014/2
N2 - The electrocatalytic activity of different, structurally well defined bimetallic PtRu surfaces in the oxygen reduction reaction was investigated by a combination of scanning tunnelling microscopy and electrochemical measurements performed under controlled mass transport conditions in a flow cell. We compare the effect of pseudomorphic Pt cover layers, mimicking the situation in a core-shell Pt/Ru nanoparticle, and of mixed PtxRu1-x monolayer surface alloys, reflecting the situation in an alloyed nanoparticle. The results unambiguously demonstrate that these bimetallic surfaces can reach activities well in excess of that of Pt(111), both for the film surfaces and the surface alloys, by optimizing the Pt surface content (surface alloys) or the Pt film thickness (film surfaces). The results are compared with simulated kinetic current-potential profiles based on existent density functional theory calculations (Greeley and Norskov, J Phys Chem C 113:4932, 2009; Lischka et al., Electrochim Acta 52:2219, 2007) revealing very good agreement in trends. Potential and limits of this approach are discussed.
AB - The electrocatalytic activity of different, structurally well defined bimetallic PtRu surfaces in the oxygen reduction reaction was investigated by a combination of scanning tunnelling microscopy and electrochemical measurements performed under controlled mass transport conditions in a flow cell. We compare the effect of pseudomorphic Pt cover layers, mimicking the situation in a core-shell Pt/Ru nanoparticle, and of mixed PtxRu1-x monolayer surface alloys, reflecting the situation in an alloyed nanoparticle. The results unambiguously demonstrate that these bimetallic surfaces can reach activities well in excess of that of Pt(111), both for the film surfaces and the surface alloys, by optimizing the Pt surface content (surface alloys) or the Pt film thickness (film surfaces). The results are compared with simulated kinetic current-potential profiles based on existent density functional theory calculations (Greeley and Norskov, J Phys Chem C 113:4932, 2009; Lischka et al., Electrochim Acta 52:2219, 2007) revealing very good agreement in trends. Potential and limits of this approach are discussed.
KW - Bimetallic surface
KW - Surface alloy
KW - Platinum monolayer
KW - Electrocatalysis
KW - Oxygen reduction reaction
KW - Scanning probe microscopy
KW - RUTHENIUM AD-ATOMS
KW - HETEROGENEOUS CATALYSIS
KW - ELECTRONIC-PROPERTIES
KW - AMMONIA-SYNTHESIS
KW - CARBON-MONOXIDE
KW - SINGLE-CRYSTAL
KW - METAL-SURFACES
KW - CO ADSORPTION
KW - PLATINUM
KW - ELECTROCATALYSTS
U2 - 10.1007/s11244-013-0177-0
DO - 10.1007/s11244-013-0177-0
M3 - Journal article
VL - 57
SP - 222
EP - 235
JO - Topics in Catalysis
JF - Topics in Catalysis
SN - 1022-5528
IS - 1-4
ER -