title: Mechanism of Hg(0) oxidation in the presence of HCl over a commercial V2O5-WO3/TiO2 SCR catalyst.
abstract: Experiments were conducted in a fixed-bed reactor containing a commercial V2O5/WO3/TiO2 catalyst to investigate mercury oxidation in the presence of HCl and O2. Mercury oxidation was improved significantly in the presence of HCl and O2, and the Hg(0) oxidation efficiencies decreased slowly as the temperature increased from 200 to 400°C. Upon pretreatment with HCl and O2 at 350°C, the catalyst demonstrated higher catalytic activity for Hg(0) oxidation. Notably, the effect of pretreatment with HCl alone was not obvious. For the catalyst treated with HCl and O2, better performance was observed with lower reaction temperatures. The results showed that both HCl and Hg(0) were first adsorbed onto the catalyst and then reacted with O2 following its adsorption, which indicates that the oxidation of Hg(0) over the commercial catalyst followed the Langmuir-Hinshelwood mechanism. Several characterization techniques, including Hg(0) temperature-programmed desorption (Hg-TPD) and X-ray photoelectron spectroscopy (XPS), were employed in this work. Hg-TPD profiles showed that weakly adsorbed mercury species were converted to strongly bound species in the presence of HCl and O2. XPS patterns indicated that new chemisorbed oxygen species were formed by the adsorption of HCl, which consequently facilitated the oxidation of mercury.
authors.affiliation: Research Center for Process Pollution Control, National Engineering Laboratory for Hydrometallurgical Cleaner Production Technology, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, China; School of Resources and Materials, Northeastern University at Qinhuangdao Branch, Qinhuangdao 066004, China. Electronic address: liuruihui2015@126.com.
authors.forename: Ruihui
authors.initials: R
authors.lastname: Liu
authors.affiliation: Research Center for Process Pollution Control, National Engineering Laboratory for Hydrometallurgical Cleaner Production Technology, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, China. Electronic address: wqxu@ipe.ac.cn.
authors.forename: Wenqing
authors.initials: W
authors.lastname: Xu
authors.affiliation: Research Center for Process Pollution Control, National Engineering Laboratory for Hydrometallurgical Cleaner Production Technology, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, China.
authors.forename: Li
authors.initials: L
authors.lastname: Tong
authors.affiliation: Research Center for Process Pollution Control, National Engineering Laboratory for Hydrometallurgical Cleaner Production Technology, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, China. Electronic address: tyzhu@ipe.ac.cn.
authors.forename: Tingyu
authors.initials: T
authors.lastname: Zhu
mesh_terms: D000327:Adsorption; D002384:Catalysis; D002713:Chlorine / Q000737:chemistry*; D008628:Mercury / Q000737:chemistry*; D010084:Oxidation-Reduction; D010087:Oxides / Q000737:chemistry*; D010100:Oxygen / Q000737:chemistry*; D014025:Titanium / Q000737:chemistry*; D014414:Tungsten / Q000737:chemistry*; D017968:Vanadium Compounds / Q000737:chemistry*
chemical_list: D010087:Oxides; D017968:Vanadium Compounds; C009495:titanium dioxide; D002713:Chlorine; C511604:tungsten oxide; C066075:vanadium pentoxide; D014025:Titanium; D008628:Mercury; D010100:Oxygen; D014414:Tungsten
keywords: Hydrogen chloride; Mechanism; Mercury; Oxidation; Vanadium-based catalyst