The Microstructure and Electrocatalytic Performance of RuO2/Ti Electrodes Thermally Formed in Air, Oxygen and Argon

• Published in: Transactions of the Institute of Metal Finishing 2000, Vol.78 (6), p.231-237
• Main Authors: Yang, L.X., Farr, J.P.G., Ashworth, M.A.
• Format: Article
• Language: English
• Subjects: capacitance; charge; Chemistry; dimensionally stable anode; electrocatalysis; Electrochemistry; Electrodes: preparations and properties; Exact sciences and technology; General and physical chemistry; morphology; Other electrodes
• ISSN: 0020-2967; 1745-9192
• DOI: 10.1080/00202967.2000.11871347

The electrocatalytic performance of RuO 2 films depends on their chemical composition, structure and surface morphology. In the present paper the structure and morphology of RuO 2 thermally formed on a titanium support in air. oxygen and argon were characterised using HRSEM. XRD and XPS. Both XRD and XPS results show that the ruthenium catalyst film thermally formed in different atmospheres was not composed of stoichiometric RuO 2 , but was a Ru (IV) (rutile type) structure highly deficient in oxygen. HRSEM revealed that ultra-fine particles existed along both flat planes and cracks and their size was dependent on the calcination environment. The in situ techniques voltammetry and a.c. impedance applied within the "double layer" region revealed that the activity of the electrodes thermally formed in different atmospheres is directly related to their ultrafine particle size. These measurements confirmed that the double layer capacitance is augmented by a pseudocapacitance due to redox processes. The maturation of the electrodes is probably related to the progressive hydration of the calcined oxide surfaces.