文摘
This study developed a heterogeneous catalytic permanganate oxidation system with ceria supported ruthenium, Ru/CeO2 (0.8鈥?as Ru), as catalyst for the first time. The catalytic performance of Ru/CeO2 toward butylparaben (BP) oxidation by permanganate was strongly dependent on its dosage, pH, permanganate concentration and temperature. The presence of 1.0 g L鈥? Ru/CeO2 increased the oxidation rate of BP by permanganate at pH 4.0鈥?.0 by 3鈥?6 times. The increase in Ru/CeO2 dosage led to a progressive enhancement in the oxidation rate of BP by permanganate at neutral pH. The XANES analysis revealed that (1) Ru was deposited on the surface of CeO2 as RuIII; (2) RuIII was oxidized by permanganate to its higher oxidation state RuVI and RuVII, which acted as the co-oxidants in BP oxidation; (3) RuVI and RuVII were reduced by BP to its initial state of RuIII. Therefore, Ru/CeO2 acted as an electron shuttle in catalytic permanganate oxidation process. LC-MS/MS analysis implied that BP was initially attacked by permanganate or RuVI and RuVII at the aromatic ring, leading to the formation of various hydroxyl-substituted and ring-opening products. Ru/CeO2 could maintain its catalytic activity during the six successive runs. In conclusion, catalyzing permanganate oxidation with Ru/CeO2 is a promising technology for degrading phenolic pollutants in water treatment.