Ruthenium versus platinum on cerium materials in wet air oxidation of acetic acid.

This study was a comparison between Ru-catalysts and similar, previously investigated, Pt-catalysts. In this paper, ruthenium catalysts for catalytic wet air oxidation are prepared, characterized and tested. Both catalysts were supported on commercial CeO2 as well as mixed oxide Zr(0.1)(Ce(0.75)Pr(0.25))(0.9)O2. The catalysts were characterized by measuring the oxygen storage capacities (OSC), BET, XRD, FTIR and chemisorption of hydrogen. In addition, the effect of sintering (treatments under H2) was compared with both of the catalysts. The comparison of the results showed that initial intrinsic activity of ruthenium is not significantly influenced by the type of the support, which is contrast to platinum. Furthermore, the particle size of Ru had an important effect on CWAO activity: the higher the particle size, the better the activity. This was different with Pt-catalysts, where the optimal particle size was smaller, having about 15% of metal dispersion.