Low-Temperature NOX (x=1, 2) Removal with •OH Radicals from Catalytic Ozonation over -FeOOH

FeOOH(H), FeOOH(P) and FeOOH(O) prepared by hydrothermal, precipitant-hydrolysis and oxidation-hydrolysis methods were tested as ozonation catalysts for the low-temperature NOX (x=1, 2) removal. FeOOH(H) exhibits higher catalytic activities than FeOOH(P) and FeOOH(O), achieving 85.6% of NOX removal efficiency with a low ozone concentration. Compared to FeOOH(P) and FeOOH(O), FeOOH(H) shows much higher BET surface areas and higher density of surface -OH, both of which are critical for the center dot OH radical generation over the catalysts. These radicals can be successfully transferred into the duct under the coupling effect of hydroxyl radicals and O-3, oxidizing and removing the NOX (x=1, 2). Results of ion chromatography (IC) indicate that the oxidation products are all NO3- without any NO2- in the tail solutions.