Catalytic wet hydrogen peroxide oxidation of p-hydroxybenzoic acid over Fe/TiO2 and 0.5Ru–3Fe/TiO2

p-Hydroxybenzoic acid (p-HBZ) degradation was achieved using catalytic wet hydrogen peroxide oxidation over Fe/TiO2 and Ru–Fe/TiO2 under mild conditions. The results showed that 71 % of p-HBZ conversion was obtained after 10 min of reaction over the 0.5Ru–3Fe/TiO2 catalyst calcined under oxygen. The influence of the H2O2/p-HBZ molar ratio (5:1, 10:1 and 15:1), reaction temperature (25, 40 and 60 °C), Fe loading (1, 2 and 3 wt%) and thermal treatment was studied. Characterization studies were performed by X-ray diffraction, N2 physisorption at 77 K, H2-TPR and elemental analysis, showing that close interaction between Ru and iron oxide species is necessary to obtain active and stable catalysts. 0.5Ru–3Fe/TiO2 C catalyst shows a high activity for the degradation of p-HBZ at 60 °C by CWHPO in the presence of H2O2. The system could be considered as a Fenton-like reaction due to the generation of radicals from H2O2 as well as the presence of iron sites on the catalyst.