The enhance effect of atomic Cl in CuCl2/TiO2 catalyst for Hg0 catalytic oxidation

• The CuCl2/TiO2 catalyst is highly active and stability for Hg0 oxidation.
• Atomic Cl and O in material play a crucial role in Hg0 conversion.
• Both HCl and O2 gases were found to be required for back to CuO or CuCl2 via intermediate.

The effect of flue gas components on the Hg0 oxidation efficiency of CuO/TiO2 and CuCl2/TiO2 catalysts was investigated. The results indicated that HCl and O2 in the atmosphere positively affect Hg0 oxidation, and HCl is more effective than O2. Meanwhile, atomic Cl and O in the catalyst also play crucial roles in the Hg0 oxidation process. Thermogravimetry (TG), X-ray Diffractograms (XRD), Brunauer–Emmet–Teller (BET) and X-ray photoelectron spectroscopy (XPS) technologies were adopted to characterize the raw CuCl2/TiO2 catalyst. The Hg0 oxidation mechanisms over CuO/TiO2 and CuCl2/TiO2 catalysts were discussed. Both HCl and O2 gases were found to be necessary to revert to CuO or CuCl2 via an intermediate step. The CuCl2/TiO2 catalyst has a potential industrial application because it has a certain oxidation activity in the absence of HCl, high stability and a large temperature window.