Synthesis of mesoprous materials with Ce-Co/KIT-6 and its mercury removal performance

The oxidation activity of elemental mercury (Hg⁰) by transition metal modified KIT-6 was investigated using a simulated element mercury (Hg⁰) adsorption reactor. The physical and chemical propertied of the catalysts were characterized by scanning electron microscope (SEM), N₂ adsorption-desorption (BET), Fourier Transform Infrared spectroscopy (FT-IR) Analysis, H₂-Temperature programmed reduction (H₂-TPR), thermogravimetric analysis (TGA). The results show that Ce-Co/KIT-6 surface area and total pore volume of the catalysts decrease after the modification. However, the pore structure and distribution after modification have little variation. The mean pore size and BET surface area of mesoporous Ce-Co/KIT-6 are 4.6 nm and 495.2 m²/g, respectively. The Ce-Co/KIT-6 shows a high Hg⁰ adsorption efficiency without O₂, the removal efficiency of Hg⁰ is about 50.67%; moreover, it has a high Hg⁰ removal efficiency of O₂ above 95% for 250 ℃, the presence of O₂ greatly contributes to mercury removal capacity of the catalyst. Oxygen enters the metal structure through changes in the valence state of Ce-Co and reacts with mercury, which may be the main mechanism of this process.