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Correlation between CO Oxidation and H Adsorption/Desorption on Pt Surfaces in a Wide pH Range: The Role of Alkali Cations
Author(s) -
García Gonzalo
Publication year - 2017
Publication title -
chemelectrochem
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.182
H-Index - 59
ISSN - 2196-0216
DOI - 10.1002/celc.201600731
Subject(s) - desorption , chemistry , alkali metal , electrochemistry , adsorption , carbon monoxide , inorganic chemistry , electrode , hydrogen , catalysis , organic chemistry
It is well‐known that hydrogen adsorption/desorption on Pt open surfaces sites (110 and 100) shows a dependence on the pH below a pure Nernstian shift. Also, it is recognized that the oxidation of CO (and organic molecules) on Pt open surface electrodes occurs at more negative potentials in alkaline media than in acidic solutions. In contrast, both electrochemical processes develop a pure Nernstian behavior at the close‐packed Pt(111) over the whole pH range. The current work employs experimental results of hydrogen desorption and carbon monoxide oxidation on Pt electrodes with different surface orientations over a wide pH range to reveal that the unusual Nernstian behavior observed at open surface sites is linked to an electrochemical process for both reactions, owing to the fact that similar absolute values are detected. Furthermore, the nature and concentration of alkali cations appear to play an important role in the mutual electrochemical process.