OXYGEN EVOLUTION ON IR-RU-SN TERNARY OXIDE-COATED ELECTRODES IN H2SO4 SOLUTION - AN APPROACH EMPLOYING STATISTICAL EXPERIMENTAL STRATEGY

A systematic modeling analysis of Ir-Ru-Sn ternary oxide-coated electrodes fabricated by thermal decomposition is performed. Using mixture experimental design, empirical models are fitted and plotted as contour diagrams which facilitate comparisons with experimental trends noted by other investigators and reveal the synergistic/antagonistic effects between the mixed oxides. The results indicate that each component demonstrates different performances in either binary (Ir-Ru, Ir-Sn, and Ru-Sn) or ternary (Ir-Ru-Sn) systems, with the Ir 75%-Ru 25% binary electrode being by far the most valuable anodic candidate for oxygen evolution in acidic media. X-ray photoelectron spectroscopy analysis shows that the Ir 75%-Ru 25% binary electrode surface is enriched with Ir, while Auger electron spectroscopy depth profile results demonstrate inhomogeneous bulk.