Compositional and Microstructural Characterization of RuO2 ‐ TiO2 Catalysts Synthesized by the Sol‐Gel Method

RuO2/TiO2 mixtures were prepared from solution using Ti(i-OPr)4 and three different precursors for RuO2, RuNO(NO3)3, and RuCl3.xH2O and tris (2, 4-pentanedionate) Ru(III). Multi-layer coatings were deposited by spin coating onto fused silica slides with and without an intermediate, 200 nm thick, vacuum deposited Ti film. Samples heat treated at 200, 300 and 400 C were studied by several techniques (Rutherford backscattering spectrometry, elastic recoil detection, nuclear reaction analysis, SEM, FTIR and XRD) to characterise morphological and compositional changes and to test the reproducibility of the preparation method. In all cases, a single crystalline phase, the solid solution of the two component oxides, was detected by XRD. The films appeared to have a low density, and hydrogen and carbon were still found in the coatings after each heat treatment; their content was reduced only at 400 C for samples B and C. The surface of the films displayed increasing percentages of TiO2. 21 refs.