Abstract
Ruthenium catalysts have been prepared by incipient wetness impregnation of ruthenium(III) nitrosylnitrate, Ru(NO)(NO(3))(3) onto high surface area titanate supports obtained by hydrothermal treatment of TiO(2) P25 in concentrated alkaline solutions. These Ru-containing catalysts were evaluated in the catalytic wet air oxidation of p-hydroxybenzoic acid (p-HBZ), a model compound representative of phenolic pollutants present in olive mills wastewaters, at 413 K and 50 bars of air. Two different titanates morphologies were tested as supports for this reaction: hydrogenotitanate nanotubes (HNT) obtained with concentrated NaOH and hydrogenotitanate nanowires (HNW) formed in the presence of highly concentrated KOH solution. The HNT and HNW supports and their corresponding supported Ru catalysts were characterized by means of N(2) adsorption-desorption, XRD, UV and TEM analyses. Results showed that the use of high surface area titanate supports led to catalysts much more active than similar Ru catalysts supported on conventional TiO(2) supports.