Hg0 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 Hg0 removal. O2 and hydrogen halides (HCl and H2S) are common oxidants
for catalytic Hg0 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 Hg0 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 H2O2 on the surface
of SACs. Spin-polarized density functional theory calculations with
van der Waals corrections (DFT-D3) revealed that Zn1–N4–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 Hg0 oxidation, providing
a new option for effective Hg0 removal.