Co-benefit of Ag and Mo for the catalytic oxidation of elemental mercury

Abstract

Abstract The performance of catalyst-combining silver (Ag) and molybdenum (Mo) for elemental mercury (Hg0) oxidation was clearly improved, and the experimental results demonstrated the synergy between Ag and Mo. The physical and chemical characterizations indicated that Ag0 and Ag2MoO4 nanoparticles existed on the surface of TiO2 for Ag(2%)–Mo–Ti. Furthermore, the oxidation ability of Mo–Ti was enhanced, and the redox temperature decreased after silver was added. The gas component analysis demonstrated that HCl was the main catalytic component, and the catalyst still had high oxidation efficiency when O2 was nonexistent. Ag(2%)–Mo–Ti had a superior resistance toward SO2. Furthermore, Hg0 breakthrough, desorption, and HCl pretreated experiments were conducted to investigate the catalytic mechanisms of Hg0 oxidation. The results indicated that Ag had an absorbency role on HCl and Hg0, and Mo and chemical adsorption oxygen had a catalytic effect on HCl. Adsorbed active Cl subsequently reacted with adsorbed Hg0 followed by the Langmuir Hinshelwood mechanism at low temperature.