Abstract:
The MnO
x/PG catalysts were prepared by supporting Mn oxides to palygorskite (PG) and used to remove Hg
0 in simulated flue gas, which were analyzd and characterized by the specific surface area analysis (BET), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). The results show that the co-effect of MnO
x and PG significantly enhances the Hg
0 removal performance; the MnO
x/PG catalyst with 8% MnO
x loading has the highest Hg
0 removal activity. The Hg
0 removal efficiency can maintain above 95% at 210 ℃ with a space velocity of 6000 h
-1 and an inlet Hg
0 concentration of 80 μg/m
3 for 400 min. O
2 can promote the Hg
0 removal by MnO
x/PG catalysts, while SO
2 and H
2O have inhibitory effects. In the presence of O
2, the inhibitory effect of SO
2 can be obviously weakened. The results of XRD, XPS and temperature programmed desorption experiments (TPD) indicate that the active components MnO
x disperse well on the surface of PG. The removal process of Hg
0 on the MnO
x/PG catalyst includes the steps of adsorption, oxidation and reaction, and HgO and HgSO
4 are generated and adsorbed on the catalyst.