Coordination tuned ozone catalytic activity of iron oxides

At present, near-ground ozone still acts as an air pollutant, posing threats to human’s health. In this study, Fe-based catalysts with different coordination environments and valance states were synthesized and the coordination environments were verified using EXAFS and XRD Rietveld fitting, while in-situ Raman and in-situ DRIFTs were employed to investigate the oxygen intermediates of ozone catalytic reaction. The following activities order for ozone catalytic reaction was obtained: [FeO 6 ] 3+ ≫ [FeO 4 ] 3+ > [FeO 6 ] 2+ ≈ [FeO 4 ] 2+ proven by DFT calculations, and α-Fe 2 O 3 with [FeO 6 ] 3+ coordination structure has a high efficiency of about 80 % after 2 h at a WHSV of 720000 mL g -1 h −1 and ozone concentration of 1000 ppm. The superior catalytic activity could be attributed to the high crystal splitting energy in the octahedral coordination structure, which could offer electrons easily for the catalytic reaction. This study provides valuable insights for the development of Fe-based ozone catalysts as well as for other transition metal oxides.