The “age” of the fundamental studies on the so-called DSAs (Dimensionally Stable Anodes) probably starts with the first paper containing a detailed study on the fundamental properties of RuO2, but the first appearance of this type of electrodes is the Beer’s patent dated 1965. The path of this research has mainly been addressed to the improvement of electrocatalytic properties without loss of service life, especially in the applications for chlor-alkali industries, and electrometallurgical processes, where environment-friendly anode materials for the oxygen evolution reaction are requested. In the above applications, the high stability in strongly acidic media is certainly an important target. The research in our laboratory aims to explore the fundamental factors responsible of the DSA® performance, which has recently led to an improvement of the level of understanding. In this sense, we have performed a systematic study on binary mixtures of Iridium and Tin oxide, which is, in given composition ranges, an interesting material for electrocatalytic coatings of Titanium. A careful tuning of the preparative path has allowed the obtainment of uniform and homogenous coatings, also at low percentage of Iridium, without losses of volatile Tin by-products, as witnessed by the morphological characterisation carried out using Scanning Electron Microscopy, Atomic Force Microscopy, Energy Dispersive X-rays Analysis and Photoemission Spectroscopy. Also the Low-Angle X-ray Diffraction technique has been widely used. Electrochemical characterisations were performed by Cyclic Voltammetry and studies on the kinetics of the Oxygen Evolution Reaction, also in non-isothermal conditions. The Tafel slope and electrocatalytic activity and stability have been scrutinized as a function of active layer composition and morphological aspects. A reaction mechanism has been proposed and, following an analysis by Conway and co-workers, an estimation of the activation parameters has been performed, to demonstrate the potential use of this method in determining the free energy of activation.
Characterization of IrO2-SnO2 film electrodes
URGEGHE, Christian;VAZQUEZ GOMEZ, Lourdes;FERRO, Sergio;DE BATTISTI, Achille
2004
Abstract
The “age” of the fundamental studies on the so-called DSAs (Dimensionally Stable Anodes) probably starts with the first paper containing a detailed study on the fundamental properties of RuO2, but the first appearance of this type of electrodes is the Beer’s patent dated 1965. The path of this research has mainly been addressed to the improvement of electrocatalytic properties without loss of service life, especially in the applications for chlor-alkali industries, and electrometallurgical processes, where environment-friendly anode materials for the oxygen evolution reaction are requested. In the above applications, the high stability in strongly acidic media is certainly an important target. The research in our laboratory aims to explore the fundamental factors responsible of the DSA® performance, which has recently led to an improvement of the level of understanding. In this sense, we have performed a systematic study on binary mixtures of Iridium and Tin oxide, which is, in given composition ranges, an interesting material for electrocatalytic coatings of Titanium. A careful tuning of the preparative path has allowed the obtainment of uniform and homogenous coatings, also at low percentage of Iridium, without losses of volatile Tin by-products, as witnessed by the morphological characterisation carried out using Scanning Electron Microscopy, Atomic Force Microscopy, Energy Dispersive X-rays Analysis and Photoemission Spectroscopy. Also the Low-Angle X-ray Diffraction technique has been widely used. Electrochemical characterisations were performed by Cyclic Voltammetry and studies on the kinetics of the Oxygen Evolution Reaction, also in non-isothermal conditions. The Tafel slope and electrocatalytic activity and stability have been scrutinized as a function of active layer composition and morphological aspects. A reaction mechanism has been proposed and, following an analysis by Conway and co-workers, an estimation of the activation parameters has been performed, to demonstrate the potential use of this method in determining the free energy of activation.I documenti in SFERA sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
