کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
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5425835 | 1395867 | 2006 | 16 صفحه PDF | دانلود رایگان |

A dual analysis is proposed in order to have a better understanding of the adsorption of the cyanide ions on a platinum electrode. The SFG (Sum Frequency Generation) spectroscopy allows the in situ vibrational study and the SFG spectra of the CNâ species adsorbed on single crystal Pt electrode allow a systematic study of the low-index platinum surfaces. This experimental work is supported by ab initio calculations using density functional theory and cluster models. For each surface orientation and each geometry, a cluster model of 20-30 Pt atoms has been built in order to interpret the chemisorption of the CNâ ions through four kinds of adsorption geometry: on-top or bridge site, bonding via C or N atoms. Geometries have been optimized and adsorption energies, electronic properties and vibrational frequencies have been computed. From the electronic properties, we can propose an analysis of the bonding mechanism for each studied kind of adsorption.The SFG spectra of the CNâ/Pt(1Â 1Â 1) system present an unique resonance owing to the top C adsorption. It is mainly the same for the CNâ/Pt(1Â 0Â 0) system. It is also the case for the SFG spectra of the CNâ/Pt(1Â 1Â 0) system recorded at negative electrochemical voltage; at more positive voltage, a second resonance appears at a lower frequency, owing to the top N adsorption.Experimental and theoretical values of the C-N stretching frequencies are in excellent agreement.
Journal: Surface Science - Volume 600, Issue 10, 15 May 2006, Pages 2138-2153