Journal article
Role of axially coordinated surface sites for electrochemically controlled carbon monoxide adsorption on single crystal copper electrodes
Physical chemistry chemical physics : PCCP, Vol.13(12), pp.5242-5251
03/28/2011
DOI: 10.1039/c0cp02064h
PMID: 21253640
Abstract
The adsorption of CO on low index copper single crystals in electrochemical environments has been investigated. The results, analysed through a combination of in situ infrared spectroscopy, DFT and cyclic voltammetry, reveal a unique adsorption behaviour when compared to previous studies on copper and the more widely studied noble metal surfaces. By employing small, weakly specifically adsorbed electrolytes, it is shown that carbon monoxide is adsorbed over a much wider electrode potential range than previously reported. The electrochemical Stark shift (δν/δE) observed is similar for the three Cu(hkl) surfaces examined despite different surface coverages. Most notably, however, is an electrochemical feature observed at ca. -1.0 V (vs. Ag/AgCl) on the (110) surface. It is proposed that this voltammetric feature arises from the reduction/oxidation of Cu(δ+) surface sites involved in the binding of carbon monoxide with the participation of the electrolyte anion. This provides additional specific sites for CO adsorption. DFT calculations support the proposed presence of low-coordination copper sites stabilised by electrolyte anions. An experimental electron transfer rate constant of 4.2 s(-1) to the Cu(δ+) surface sites formed was found. These new observations concerning the surface electrochemistry of CO on Cu indicate that the electrocatalytic behaviour of Cu electrodes in processes such as CO(2) reduction need to be re-evaluated to take account of the rich adsorption behaviour of CO, including the co-adsorption of the electrolyte anion to these sites.
Details
- Title: Subtitle
- Role of axially coordinated surface sites for electrochemically controlled carbon monoxide adsorption on single crystal copper electrodes
- Creators
- Scott K Shaw - Chemistry Department, University of Liverpool, Liverpool, UK L69 7ZD. skshaw@email.arizona.eduAntonio BernáJuan Miguel FeliuRichard J NicholsTimo JacobDavid J Schiffrin
- Resource Type
- Journal article
- Publication Details
- Physical chemistry chemical physics : PCCP, Vol.13(12), pp.5242-5251
- Publisher
- England
- DOI
- 10.1039/c0cp02064h
- PMID
- 21253640
- ISSN
- 1463-9076
- eISSN
- 1463-9084
- Language
- English
- Date published
- 03/28/2011
- Academic Unit
- Chemistry
- Record Identifier
- 9983985941302771
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