Plasma-induced adsorption of elemental mercury on TiO2 supported metal oxide catalyst at low temperatures.

A plasma–catalyst reactor was used for the adsorption of elemental mercury at low temperatures. SiO 2 , TiO 2 and SiO 2 or TiO 2 supported transition metal oxide catalysts were packed in the plasma discharge zone for adsorption enhancement. The results indicated that non-thermal plasma could induce the adsorption of elemental mercury effectively by catalysts. TiO 2 displays much higher adsorption efficiency than SiO 2 does. The adsorption efficiency is greatly improved by loading transition metal oxides on TiO 2 . Mn/TiO 2 is the most efficient catalyst, and ~ 99% of Hg 0 adsorption efficiency can be obtained under a SED of 2.3 ± 0.3 J L − 1 . The interaction between the plasma and catalyst was also investigated. The chemical properties of the catalyst, such as the active sites and electron transfer capacity, are key factors that affect adsorption efficiency. The mercury adsorption in plasma–catalyst reactor results primarily from the interaction between weakly adsorbed mercury and activated oxygen on catalyst surface induced by plasma. In addition, the effect of the O 2 concentration and HCl on mercury adsorption efficiency was investigated. The adsorption efficiency has a logarithmic correlation with O 2 concentration in the gas flow. [ABSTRACT FROM AUTHOR]