Oxygen reduction reaction spectroscopy

Lewera A, Inukai J, Zhou WP, Cao D, Duong HT, Alonso-Vante N, Wieckowski A (2007) Chalcogenide oxygen reduction reaction catalysis X-ray photoelectron spectroscopy with Ru, Ru/Se and Ru/S samples emersed from aqueous media. Electrochim Acta 52 5759-5765... 

Fig. 43. Double-logarithmic plot of the electrode polarization resistance versus the microelectrode diameter measured with impedance spectroscopy (ca. 800 °C) at (a) a cathodic dc bias of -300 mV, and (b) at an anodic dc bias of +300 mV. In (b) the first data point of the 20-pm microelectrode is not included in the fit. (c) Sketch illustrating the path of the oxygen reduction reaction for cathodic bias, (d) Path of the electrochemical reaction under anodic bias the rate-determining step occurs close to the three-phase boundary.

In the case of iron phthalocyanine catalyst dispersed on carbon, infrared spectroscopy measurements enabled to confirm the series mechanistic pathway for the ORR in the high overpotential domain (below 0.7 V vs RHE). Two intermediates species, 02 and H02 and two products, water (majority product) and hydrogen peroxide could be identified. However, since only few studies are led on the oxygen reduction reaction by infrared spectroscopy, a confident attribntion of the different vibrational transitions observed to a particnlar intermediate remains difficult. 

Kuang, R, Zhang, D., Li, Y., Wan, Y, and Hou, B. 2009. Electrochemical impedance spectroscopy analysis for oxygen reduction reaction in 3.5% NaCl solution. Journal of Solid State Electrochemistry 13, 385-390. 

Methanol oxidation on CNF- and CNT-supported Pt-Ru particles in liquid electrolytes has been studied using cyclic voltammetry, chronoamperometry [13,231-237], and electrochemical impedance spectroscopy [236]. Rotating disk electrode and linear potential sweep voltammetry in liquid electrolytes were used to study the oxygen reduction reaction on Pt supported on CNTs and CNFs (see,... 

Ziegelbauer JM, Gatewood D, Gulla AF, Ramaker DE, Mukerjee S (2006) X-ray absorption spectroscopy studies of water activation on RhxSy electrocatalyst for oxygen reduction reaction application. Electrochem Solid State Lett 9 A430-A434... 

In attempts to simulate the experimentally observed oxygen reduction reaction, several kinetic models have been reported in the literature, based on various proposed ORR mechanisms [38—41]. These models employed either the associative or the dissociative model. The former was used by Antoine et al. [38] in their simulation of a polarization curve and impedance spectra, and by Du et al. [40] in a model-based electrochemical impedance spectroscopy study. Antoine et al. considered the following reaction steps ... 

Adlerhas investigated the behaviour of LSC porous electrodes by AC impedance spectroscopy and has found that the oxygen reduction reaction is limited by surface chemical exchange and solid state diffusion, contrary to the commonly accepted view that the electrode reactions are charge transfer limited. Furthermore he has also found that the reduction reaction extends over several micrometres and under certain conditions may approach the thickness of the electrode. Isotope exchange measurements on dense LSC deposited on a Ceo.9Cao.iOi,9 electrolyte were performed by Kawada et These experiments showed that the... 

However, due to a different experimental setup, the assignation of these species could not be confirmed from the infrared spectroscopy measurements carried out on a gold catalyst in alkaline medium, " which was found to present an exclusive series of oxygen reduction pathway. " The presence of these species as intermediates in the ORR mechanism was observed by Raman spectroscopy coupled with electrochemistiy in acidic medium on a gold electrode with bismuth adatoms. " Later, this mechanistic study of ORR by Raman spectroscopy was extended to a gold electrode in alkaline medium "" with an evidence for O2 formation as a reaction intermediate. H02 was also identified, but as a product of the ORR in alkaline medium. 

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