Investigations on the Formation of RuO2/ZrO2-Based Electrocatalytic Thin Films by Surface Analysis Techniques

Secondary ion mass spectrometry (SIMS) was used to follow the evolution of RuO2/ZrO2 film electrodes. The coating mixtures with compositions 20% Ru + 80% Zr and 50% Ru + 50% Zr prepared on titanium supports from isopropanolic solutions of RuCl3 x 3H2O and ZrOCl2 x 8H2O precursors were heated to 200, 300, and 500 °C and analyzed by SIMS. Cl- concentration depth profiles as ion ZrOCl2 precursor in the outer part of the film at low temperature and noble metal content and a rather uniform distribution at elevated temperatures. Zr+/Ru+ ion intensity ratios showed the relative enrichment of ruthenium in the near surface region at 500 °C, while slight accumulation of zirconia at the surface was evidenced for both compositions in harmony with the results of emission FTIR measurements. No reaction between the oxide components or between coatings and support was identified in the systems investigated.