Removal of vapor-phase elemental mercury by N-doped CuCoO 4 loaded on activated carbon

Abstract

The adsorption ability for vapor-phase Hg° on commercially available granular activated carbon (AC) loaded with CuCoO 4 (AC–C), CuCoO 4 + NH 4Cl (AC–Cl), and CuCoO 4 + NH 4Br (AC–Br) were investigated in an attempt to produce more economic and effective sorbents for the control of Hg o emission from combustion processes. According to the X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Brunauer–Emmett–Teller (BET) and mass balance analysis on mercury, we found that N-doped AC–C had bigger S BET and the nitrogen doping greatly improved CuCoO 4 Hg o oxidation ability. It was considered that nitrogen atoms in doped CuCoO 4 polycrystalline and anion Cl −/Br - activated by AC and N-doped CuCoO 4 were responsible for the significant enhancement in Hg o oxidation ability of AC–Cl and AC–Br. We explored the Hg o oxidation ability of the three kinds of materials under various loading values and adsorption temperatures. We found that AC–Cl and AC–Br were more sensitive to loading value and had much higher Hg o oxidation ability than AC–C over a wide range temperature. The longevities of AC–C, AC–Cl and AC–Br were all less than the corresponding Al 2O 3 carrier material due to CuCoO 4 decomposition effect on AC, which destroyed the porous structure of AC. The effect of 0.31 vol.% SO 2 on the Hg o oxidation ability of AC–C, AC–Cl and AC–Br was insignificant which indicated that N-doping did not adversely affect Co 3+ and Cu 2+-octahedral structure.