Oxidation of formaldehyde and ethanol on Au(1 1 1) and Au(1 1 1) modified by spontaneously deposited Ru in sulfuric acid solution
The oxidation of formaldehyde and ethanol on both pure Au(1 1 1) and Au(1 1 1) modified by approximately 0.3 monolayer (ML) of spontaneously deposited Ru was studied by cyclic voltammetry (CV) in 0.5 M H 2SO 4 solution containing either 0.25 M formaldehyde or 0.35 M ethanol. In situ scanning tunneli...
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Published in | Electrochimica acta Vol. 54; no. 23; pp. 5408 - 5412 |
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Main Authors | , |
Format | Journal Article |
Language | English |
Published |
Kidlington
Elsevier Ltd
30.09.2009
Elsevier |
Subjects | |
Online Access | Get full text |
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Summary: | The oxidation of formaldehyde and ethanol on both pure Au(1
1
1) and Au(1
1
1) modified by approximately 0.3 monolayer (ML) of spontaneously deposited Ru was studied by cyclic voltammetry (CV) in 0.5
M H
2SO
4 solution containing either 0.25
M formaldehyde or 0.35
M ethanol.
In situ scanning tunneling microscopy (STM) and CV were employed to characterize the Au(1
1
1) and Ru/Au(1
1
1) surfaces. The oxidation of HCHO on Ru/Au(1
1
1) commences at 0.1
V more negative potential than on pure Au(1
1
1). From 0.25 to 0.55
V
vs. (Ag/AgCl), the reaction occurs with increasing current, showing a peak at a potential of 0.43
V. It is assumed that the increasing anodic activity of the Ru/Au(1
1
1) surface is associated with the oxidation of some reaction intermediates, facilitated by the presence of Ru in its metallic state. On the other hand, the oxidation of ethanol on Ru/Au(1
1
1) commences at 0.1
V more positive potential than on pure Au(1
1
1), and proceeds in the potential region from 0.2 to 0.5
V with significantly smaller currents, showing a peak at 0.43
V. This inhibiting effect is explained by the deactivation of the most active Au(1
1
1) step sites by high coverage with Ru islands. The appearance of a small peak at 0.43
V is most likely associated to the oxidation of some intermediates during ethanol oxidation at the Ru/Au step sites formed on the Au(1
1
1) terraces by the presence of a small coverage with Ru islands. |
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Bibliography: | ObjectType-Article-2 SourceType-Scholarly Journals-1 ObjectType-Feature-1 content type line 23 |
ISSN: | 0013-4686 1873-3859 |
DOI: | 10.1016/j.electacta.2009.04.031 |