Removal of vapor-phase elemental mercury by N-doped CuCoO4 loaded on activated carbon

The adsorption ability for vapor-phase Hg° on commercially available granular activated carbon (AC) loaded with CuCoO4 (AC–C), CuCoO4 + NH4Cl (AC–Cl), and CuCoO4 + NH4Br (AC–Br) were investigated in an attempt to produce more economic and effective sorbents for the control of Hgo 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 SBET and the nitrogen doping greatly improved CuCoO4 Hgo oxidation ability. It was considered that nitrogen atoms in doped CuCoO4 polycrystalline and anion Cl−/Br- activated by AC and N-doped CuCoO4 were responsible for the significant enhancement in Hgo oxidation ability of AC–Cl and AC–Br. We explored the Hgo 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 Hgo 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 Al2O3 carrier material due to CuCoO4 decomposition effect on AC, which destroyed the porous structure of AC. The effect of 0.31 vol.% SO2 on the Hgo oxidation ability of AC–C, AC–Cl and AC–Br was insignificant which indicated that N-doping did not adversely affect Co3+ and Cu2+-octahedral structure.