Design of Single-Atom Catalysts for Hg-0 Oxidation Using H2O2

Hg-0 removal is the most difficult part in mercury purification due to its insolubility in water and strong volatility. Catalytic oxidation is the main method for Hg-0 removal. O-2 and hydrogen halides (HCl and H2S) are common oxidants for catalytic Hg( )(0)oxidation. However, previous studies showed that current catalytic oxidation routes have sluggish kinetics and may cause secondary pollution. Herein, we propose a new pathway for catalytic Hg-0 oxidation on the surface of single-atom catalysts (SACs) using the green oxidant H2O2. Some potential catalysts were screened by analyzing the adsorption and activation mechanism of H(2)O(2 )on the surface of SACs. Spin-polarized density functional theory calculations with van der Waals corrections (DFT-D3) revealed that Zn-1-N-4-C has the lowest rate-determining step barrier (0.35 eV) among the analyzed systems. This study proposes a promising pathway for a kinetically facile catalytic Hg-0 oxidation, providing a new option for effective Hg-0 removal.