CuFe₂O₄ is regarded as a promising candidate of catalyst for Hg⁰ oxidation in industrial flue gas. However, the microcosmic reaction mechanism governing mercury oxidation on CuFe₂O₄ remains elusive. Herein, experiments and quantum chemistry calculations were conducted for understanding the chemical reaction mechanism of oxygen-assisted mercury oxidation on CuFe₂O₄. CuFe₂O₄ shows the optimal catalytic activity towards mercury oxidation at 150 ºC. The reactivity difference of different lattice oxygen species is associated with its atomic coordination environment. The lattice oxygen coordinating with two octahedral Cu atoms and a tetrahedral Fe atom shows higher catalytic activity towards mercury oxidation than other lattice oxygen atoms. The inverse spinel structure of CuFe₂O₄ is favorable for O₂ activation due to the Jahn-Teller effect, thereby promoting mercury oxidation. O₂ molecule preferably adsorbs on iron active site and dissociates into active oxygen species. Hg⁰ oxidation is a three-step reaction process: Hg⁰ adsorption, Hg(ads) → HgO(ads), and HgO desorption. The energy barrier of mercury oxidation by chemisorbed oxygen is lower than that of mercury oxidation by lattice oxygen. The chemisorbed oxygen preserves higher reactivity towards mercury oxidation than lattice oxygen. Hg(ads) → HgO(ads) is the rate-determining step of mercury oxidation by chemisorbed oxygen because of the higher energy barrier of 116.94 kJ/mol. This work could provide the theoretical guidance for the diversified structure design of highly-efficient catalysts used for elemental mercury oxidation.

CuFe ₂ O ₄被认为是工业烟气中Hg ⁰氧化的有前途的催化剂候选者。然而，在CuFe ₂ O ₄上控制汞氧化的微观反应机制仍然难以捉摸。在此，通过实验和量子化学计算来理解氧辅助汞氧化在 CuFe ₂ O ₄上的化学反应机理。CuFe ₂ O ₄显示了在 150 ºC 时对汞氧化的最佳催化活性。不同晶格氧物种的反应性差异与其原子配位环境有关。与两个八面体Cu原子和一个四面体Fe原子配位的晶格氧比其他晶格氧原子对汞氧化表现出更高的催化活性。由于Jahn-Teller效应，CuFe ₂ O ₄的反尖晶石结构有利于O ₂活化，从而促进汞氧化。O ₂分子优选吸附在铁活性位点上并解离成活性氧物质。Hg ⁰氧化是一个三步反应过程：Hg ⁰吸附、Hg(ads) → HgO(ads) 和 HgO 解吸。化学吸附氧氧化汞的能垒低于晶格氧氧化汞的能垒。与晶格氧相比，化学吸附的氧对汞氧化保持更高的反应性。Hg(ads) → HgO(ads) 是化学吸附氧氧化汞的速率决定步骤，因为其能量势垒较高，为 116.94  kJ/mol。该工作可为用于元素汞氧化的高效催化剂的多样化结构设计提供理论指导。