Potential Dependence of Cyanide Adsorption at a Pt Electrode in Acidic Solution: An Electrochemical in Situ Infrared Spectroscopic Study
| Autor: | Shao Xiong Liu, Wenhua Zhang, Jinlong Yang, Jun Cai, Yong Li Zheng, Yan-Xia Chen, Jie Xu |
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| Rok vydání: | 2013 |
| Předmět: | |
| Zdroj: | The Journal of Physical Chemistry C. 117:15562-15570 |
| ISSN: | 1932-7455 1932-7447 |
| DOI: | 10.1021/jp400465h |
| Popis: | Cyanide adsorption at the Pt film electrode in 0.1 M HClO4 is examined by electrochemical in situ infrared spectroscopy under attenuated total reflection configuration. N-bound Pt–NC with —N≡C stretching frequency from 2060 to 2135 cm–1, C-bound Pt–CN with —C≡N stretching frequency between 2140 and 2160 cm–1, and a trans-(HN═CH) adsorbate with C═N stretching frequency at 1639 cm–1 are identified; the latter only adsorbs at 0.05 V. The evolution of the spectral features reveal that the initial adsorption state of cyanide is in the form of Pt–NCHad, and then it fast splits into Pt–NC; furthermore, Pt—N≡C will slowly reorient to Pt—C≡N at longer adsorption time. The orientation of cyanide adsorbate at the Pt electrode surface is further confirmed by (i) the fact that the Stark slope for the —N≡C band is ca. 3 times larger than that for —C≡N and (ii) the spectral behavior of coadsorption of CO onto the presaturated cyanide adlayer: for Pt—N≡C, coadsorbed CO causes a blue shift in C≡N stretching frequency with... |
| Databáze: | OpenAIRE |
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