Transport effects in the electrooxidation of methanol studied on nanostructured Pt/glassy carbon electrodes
Artikel i vetenskaplig tidskrift, 2010

Transport effects in the methanol oxidation reaction (MOR) were investigated using nanostructured Pt/glassy carbon (GC) electrodes and, for comparison, a polycrystalline Pt electrode. The nanostructured Pt/GC electrodes, consisting of a regular array of catalytically active cylindrical Pt nanostructures with 55 +/- 10 nm in diameter and different densities supported on a planar GC substrate, were fabricated employing hole-mask colloidal lithography (HCL). The MOR measurements were performed under controlled transport conditions in a thin-layer flow cell interfaced to a differential electrochemical mass spectrometry (DEMS) setup. The measurements reveal a distinct variation in the MOR activity and selectivity (product distribution) with Pt nanostructure density and with electrolyte rate, showing an increasing overall activity, reflected by a higher Faradaic reaction current, as well as a pronounced increase of the turnover frequency for CO(2) formation and of the CO(2) current efficiency with decreasing flow rate and increasing Pt coverage. These findings are discussed in terms of the "desorption-readorption-reaction" model introduced recently (Seidel et al. Faraday Discuss 2008, 140, 67). Finally, consequences for applications in direct methanol fuel cells are outlined.

Författare

Y.E. Seidel

Universität Ulm

A. Schneider

Universität Ulm

Z. Jusys

Universität Ulm

Björn Wickman

Kompetenscentrum katalys (KCK)

Chalmers, Teknisk fysik, Kemisk fysik

Bengt Herbert Kasemo

Kompetenscentrum katalys (KCK)

Chalmers, Teknisk fysik, Kemisk fysik

R.J. Behm

Universität Ulm

Langmuir

0743-7463 (ISSN) 1520-5827 (eISSN)

Vol. 26 5 3569-3578

Ämneskategorier

Atom- och molekylfysik och optik

DOI

10.1021/la902962g