| 卤族轴向配位原子对Fe-N4位点氧还原活性的调控机制：密度泛函理论研究 | |
| Regulation mechanism of halogen axial coordination atoms on the oxygen reduction activity of Fe-N4 site: A density functional theory study | |
| 摘要: 采用密度泛函理论构建了不同卤族轴向配位原子修饰的碳载Fe-N4位点(Fe原子与同一水平面的4个N原子配位成键)模型(Fe-N4-F/C、Fe-N4-Cl/C和Fe-N4-Br/C)，通过计算上述模型的态密度、Mulliken电荷、氧还原中间体吸附能以及氧还原自由能，深入研究卤族轴向配位原子对Fe中心电子结构和吸附行为的调控机理，明确不同卤族轴向原子与Fe-N4位点氧还原活性之间的构效关系。计算结果发现，引入Br作为轴向配位原子可以有效优化Fe原子的电子结构，从而适当降低Fe中心对OH*中间体的吸附强度，促进OH*解吸反应顺利进行。与Fe-N4/C模型相比，Fe-N4-Br/C模型具有更低的决速步骤(即OH*解吸)反应能垒。因此预测卤族轴向配位原子修饰策略能够改善Fe-N4位点的氧还原本征催化活性。 | |
| 关键词: 氧还原反应 Fe-N4位点 卤族轴向配位原子 电子结构 密度泛函理论 | |
| 基金项目: 内蒙古自治区直属高校基本科研业务费项目(No.JY20250031)资助。 | |
| Abstract: A series of halogen axial coordination atoms-modified Fe-N4 (Fe atoms coordinated with four N atoms on the same horizontal plane to form bonds) models (Fe-N4-F/C, Fe-N4-Cl/C, and Fe-N4-Br/C) were constructed based on the density functional theory. All density functional theory (DFT) calculations were carried out using the Dmol3 code in the Materials Studio package. By calculating the partial density of states, Mulliken charge, adsorption energy of intermediates, and free energy of oxygen reduction reaction (ORR), the regulation mechanism of halogen axial coordination atoms on the electronic structure and adsorption behavior of Fe atoms was studied. The structure-activity relationship between halogen axial coordination atoms and the catalytic activity of the Fe-N4 site was also investigated. The results of calculations reveal that the introduction of Br as the halogen axial coordination atoms can optimize the electronic structure of the Fe atom, thus weakening the bonding strength of OH* intermediates on the Fe center. As a result, the Fe-N4-Br/C possesses a lower energy barrier of the rate-determining step (desorption of OH* intermediates) compared to Fe-N4/C, indicating better ORR kinetics process and intrinsic activity of the Fe-N4-Br/C. Therefore, it is speculated that the introduction of halogen axial coordination atoms can improve the catalytic activity of Fe-N4 sites for ORR. | |
| Keywords: oxygen reduction reaction Fe-N4 site halogen axial coordination atom electronic structure density functional theory | |
| 投稿时间：2024-12-30 修订日期：2025-02-18 | |
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| 徐昊,李若鹏,杨培霞,刘安敏,白杰.卤族轴向配位原子对Fe-N4位点氧还原活性的调控机制：密度泛函理论研究[J].无机化学学报,2025,41(4):695-701. | |
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