Elemental mercury (Hg⁰), mostly from coal combustion, poses a critical threat to ecosystems and the health of human beings, as it causes several fatal human diseases. Thus, there has been an effort to strengthen regulations around the world. Catalytic oxidation of Hg⁰ into HgCl₂ is considered an economical and practical option, and selective catalytic reduction catalysts such as titania-supported vanadia (VO_x/TiO₂) have been shown to also oxidize Hg⁰ to Hg²⁺. Herein, based on density functional theory (DFT) calculations, we demonstrate the relationship between the coordinative environment of V in the VO_x/TiO₂ catalyst and the catalytic activity towards Hg⁰ oxidation, as well as the effect of hydroxylation. We mechanistically estimate the Hg⁰ oxidation activity of several VO_x/TiO₂ models using previously reported mechanisms. We also explore the temperature (T)- and pressure (p)-dependent thermodynamic stabilities of the VO_x/TiO₂ catalyst models by calculating the Gibbs free energy of formation ($\mathrm{\Delta }{G}^{\mathit{form}}$). Finally, the thermodynamic (T, p) conditions that favor high activity of the VO_x/TiO₂ catalyst are suggested.

大部分来自煤炭燃烧的元素汞（Hg ⁰）对生态系统和人类健康构成严重威胁，因为它会导致多种致命的人类疾病。因此，已经在努力加强全世界的法规。将Hg ⁰催化氧化为HgCl ₂被认为是一种经济实用的选择，并且选择性催化还原催化剂（例如二氧化钛负载的钒）（VO _x / TiO ₂）也已将Hg ⁰氧化为Hg ²⁺。在此，基于密度泛函理论（DFT）计算，我们证明了VO _x / TiO ₂中V的配位环境之间的关系。催化剂和对Hg ⁰氧化的催化活性，以及羟基化作用。我们使用先前报道的机理，机械地估计了几种VO _x / TiO ₂模型的Hg ⁰氧化活性。我们还通过计算形成的吉布斯自由能来探索VO _x / TiO ₂催化剂模型的温度（T）和压力（p）依赖的热力学稳定性（$\mathrm{\Delta }{G}^{\mathit{形式}}$）。最后，提出了有利于VO _x / TiO ₂催化剂高活性的热力学条件（T，p）。