Oxidation and adsorption of gas-phase Hg0 over a V2O5/AC catalyst

Abstract

Oxidation and adsorption of gas-phase Hg⁰ over a V₂O₅/AC catalyst was studied in N₂ and N₂ + O₂ atmospheres. The results showed that the V₂O₅/AC catalyst had a high Hg⁰ capture capability in N₂ and N₂ + O₂, which can be attributed to the critical role of V₂O₅ oxidation activity for oxidizing Hg⁰ to Hg²⁺ (form HgO). O₂ promoted Hg⁰ oxidation and its role was mainly to resume the oxidation activity of V₂O₅ by replenishing O to the used V₂O₅ sites. It was found that only a portion of the V₂O₅ sites on the V₂O₅/AC surface were effective for Hg⁰ oxidation. The high Hg⁰ capture capability of V₂O₅/AC was due to the combined effects of oxidation and adsorption, and the effect extent of each was different at different temperatures.