Effect of the composition and surface functional groups of Fe-Ni bimetal oxides catalysts in catalytic ozonation process

In this study, Fe-Ni bimetal oxides (Fe-NiO x ) catalysts were used to activate O 3 in a heterogeneous system. This research focuses on the degradation mechanism of dimethyl phthalate (DMP) by adding Fe-NiO x catalysts which activated the O 3 decomposition to generate strong oxidative hydroxyl radicals (•OH). The experimental results showed that O 3 /Fe-NiO x catalyst calcinated under 500 °C achieved 47.75% higher DMP removal efficiency when compared with ozonation of DMP without the catalyst. Besides, control experimental data suggested that the adsorption of DMP was negligible ( x . Thus, it was concluded that the removal of DMP was due to the catalytic ability of Fe-NiO x rather than the adsorption of DMP onto the catalysts. Moreover, the unsatisfactory performance of Fe-NiO x catalysts calcinated in the presence of N 2 revealed that O 2 played an important part in affecting the crystalline degree of catalysts during the synthesis process. Meanwhile, the X-ray Photoelectron Spectroscopy (XPS) and Fourier Transform Infrared Spectroscopy (FT-IR) characterization analysis indicated that calcination temperature was an indispensable factor that influenced the relative content of Ni 2+ and hydroxyl groups (−OH) in Fe-NiO x catalysts. Furthermore, the relative content of Ni 2+ had a greater effect on catalysts9 activity because of the electron transfer between multivalent metal states.