Naslov
Impedance modeling of ruthenium modified glass-like carbon electrodes

Autori
Horvat-Radošević, Višnja ; Magdić, Katja ; Kvastek, Krešimir

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Izvornik
63rd Annual Meeting of the International Society of Electrochemistry / - Prag : International Society of Electrochemistry, 2012

Skup
63rd Annual Meeting of the International Society of Electrochemistry

Mjesto i datum
Prag, Češka Republika, 19.08.2012. - 24.08.2012

Vrsta sudjelovanja
Poster

Vrsta recenzije
Nije recenziran

Ključne riječi
GC-Ru composite; EIS; modeling

Sažetak
Impedance modeling of ruthenium modified glass- like carbon, GC, electrodes in H2SO4 electrolyte solution is presented. Ruthenium modification of GC electrodes was made by cathodic deposition of Ru from the (NH4)2RuCl6/H2SO4 solution at -0.850 V vs. SSE. Impedance modeling has been made on the basis of experimental impedance spectra measured at polarization potentials, E, within double-layer region of GC (-0.600 V to +0.600 V vs. SSE), underpotential deposition of hydrogen, UPD H, at ruthenium (~ -0.500 to -0.650 V vs. SSE) and hydrogen evolution reaction, HER, (~ -0.650 to -0.800 V vs. SSE) at ruthenium. According to impedance spectra measured over the frequency range of 105 to 0.01 Hz between -0.400 and -0.775 V vs. SSE, the reactions of UPD H and HER at ruthenium are occuring in parallel to double-layer charging/discharging coupled with fast faradaic reaction of surface oxygen species at GC electrodes. Two impedance branches in parallel, pertaining to separate responses of GC and ruthenium respectively, indicate formation of GC/Ru composite at GC electrode. All of this is in full accordance to the profiles of cyclic voltammograms, CVs, with characteristic peaks of: A) UPD H at Ru, B) redox reaction of surface oxygen species of hydroquinone/quinone-type at GC and C) formation of Ru (IV) oxy-hydroxide.

Izvorni jezik
Engleski

Znanstvena područja
Kemija

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