Catalytic wet hydrogen peroxide oxidation of p-hydroxybenzoic acid over Fe/TiO 2 and 0.5Ru–3Fe/TiO 2

p-Hydroxybenzoic acid (p-HBZ) degradation was achieved using catalytic wet hydrogen peroxide oxidation over Fe/TiO 2 and Ru–Fe/TiO 2 under mild conditions. The results showed that 71 % of p-HBZ conversion was obtained after 10 min of reaction over the 0.5Ru–3Fe/TiO 2 catalyst calcined under oxygen. The influence of the H 2 O 2 /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, N 2 physisorption at 77 K, H 2 -TPR and elemental analysis, showing that close interaction between Ru and iron oxide species is necessary to obtain active and stable catalysts. Graphical Abstract 0.5Ru–3Fe/TiO 2 C catalyst shows a high activity for the degradation of p-HBZ at 60 °C by CWHPO in the presence of H 2 O 2 . The system could be considered as a Fenton-like reaction due to the generation of radicals from H 2 O 2 as well as the presence of iron sites on the catalyst.