Novel sorbents of non-metal-doped spinel Co3O4 for the removal of gas-phase elemental mercury.
N-doping technology is introduced to improve Co3O4's Hg0 removal ability and anion activation ability for the first time. The adsorption tests show that N-doped Co3O4 has a higher S(BET) and greater Hg0 removal ability. The reaction mechanism has been carefully studied using a number of different analyses methods such as X-ray diffraction, Brunauer-Emmett-Teller, and X-ray photoelectron spectroscopy. The analysis results illustrate that N atoms have been doped into a Co3O4 matrix as anions and are thoughtto substitute for O atoms. Anions, such as Cl- and Br-, can be activated by N-doped Co3O4 and then oxidize Hg0. It is considered that nitrogen atoms in polycrystalline N-doped Co304 are responsible for the significant enhancement of Hg0 removal ability. Different NH4Cl or NH4Br adulteration values have been tested, and the results show that 50 mol % NH4Cl or 40 mol % NH4Br doped Co3O4 have the highest Hg0 removal ability. Compared with Co3O4, N-doped Co3O4 has a longer breakthrough time and better SO2 antipoisoning ability. On the basis of the above analyses, possible Hg0 oxidation mechanisms of N-doped Co3O4 are provided.
Mei
Zhijian
Z
School of Environmental Science and Engineering, Shanghai Jiao Tong University, 800 Dong Chuan Road, Shanghai 200240, PR China.
Shen
Zhemin
Z
Wang
Wenhua
W
Zhang
Yejian
Y
D000327:Adsorption; D000393:Air Pollutants / Q000737:chemistry*; D000397:Air Pollution / Q000517:prevention & control; D000537:Aluminum Oxide / Q000737:chemistry; D000643:Ammonium Chloride / Q000737:chemistry*; D001965:Bromides / Q000737:chemistry*; D003035:Cobalt / Q000737:chemistry*; D008628:Mercury / Q000737:chemistry*; D010084:Oxidation-Reduction; D010087:Oxides / Q000737:chemistry*; D000644:Quaternary Ammonium Compounds / Q000737:chemistry*; D013458:Sulfur Dioxide / Q000737:chemistry; D013696:Temperature
D000393:Air Pollutants; D001965:Bromides; D010087:Oxides; D000644:Quaternary Ammonium Compounds; D000643:Ammonium Chloride; D013458:Sulfur Dioxide; D003035:Cobalt; D008628:Mercury; D000537:Aluminum Oxide; C051470:ammonium bromide; C060728:cobalt oxide