Liu Ling, Sun Xin, Li Yonghui, Zhang Xiao-Dong
Tianjin Key Laboratory of Brain Science and Neural Engineering, Academy of Medical Engineering and Translational Medicine, Tianjin University, Tianjin 300072, China.
Department of Physics and Tianjin Key Laboratory of Low Dimensional Materials Physics and Preparing Technology, School of Sciences, Tianjin University, Tianjin 300350, China.
ACS Omega. 2024 Jul 29;9(32):35144-35153. doi: 10.1021/acsomega.4c04990. eCollection 2024 Aug 13.
Developing biomimetic catalysts with excellent peroxidase (POD)-like activity has been a long-standing goal for researchers. Doping nonmetallic atoms with different electronegativity to boost the POD-like activity of Fe-N-C single-atom catalysts (SACs) has been successfully realized. However, the introduction of heteroatoms to regulate the coordination environment of the central Fe atom and thus influence the activation of the HO molecule in the POD-like reaction has not been extensively explored. Herein, the effect of different doping sites and numbers of heteroatoms (P, S, B, and N) on the adsorption and activation of HO molecules of Fe-N sites is thoroughly investigated by density functional theory (DFT) calculations. In general, alternation in the catalytic efficiency directly depends on the transfer of electrons and the geometrical shifts near the Fe-N site. First, the symmetry disruption of the Fe-N site by P, S, and B doping is beneficial to the activation of HO due to a significant reduction in the adsorption energies. In some cases, without Fe-N site disruption, the configurations fail to modulate the adsorption behavior of HO. Second, Fe-N-P/S configurations exhibit a stronger affinity for HO molecules due to the significant out-of-plane distortions induced by larger atomic radii of P and S. Moreover, the synergistic effects of Fe and doping atoms P, S, and B with weaker electronegativity than that of N atoms promote electron donation to generated oxygen-containing intermediates, thus facilitating subsequent electron transfer with other substrates. This work demonstrates the critical role of tuning the coordinating environment of Fe-N active centers by heteroatom doping and provides theoretical guidance for controlling the types by breaking the symmetry of SACs to achieve optimal POD-like catalytic activity and selectivity.
开发具有优异类过氧化物酶（POD）活性的仿生催化剂一直是研究人员长期以来的目标。通过掺杂具有不同电负性的非金属原子来提高Fe-N-C单原子催化剂（SACs）的类POD活性已成功实现。然而，引入杂原子以调节中心Fe原子的配位环境从而影响类POD反应中HO分子的活化尚未得到广泛研究。在此，通过密度泛函理论（DFT）计算深入研究了不同掺杂位点和杂原子（P、S、B和N）数量对Fe-N位点HO分子吸附和活化的影响。一般来说，催化效率的变化直接取决于电子转移和Fe-N位点附近的几何位移。首先，P、S和B掺杂导致Fe-N位点的对称性破坏有利于HO的活化，这是由于吸附能显著降低。在某些情况下，在没有Fe-N位点破坏的情况下，构型无法调节HO的吸附行为。其次，由于P和S较大的原子半径引起显著的面外畸变，Fe-N-P/S构型对HO分子表现出更强的亲和力。此外，Fe与电负性比N原子弱的掺杂原子P、S和B的协同作用促进了向生成的含氧中间体的电子捐赠，从而促进了随后与其他底物的电子转移。这项工作证明了通过杂原子掺杂调节Fe-N活性中心配位环境的关键作用，并为通过打破SACs的对称性来控制类型以实现最佳类POD催化活性和选择性提供了理论指导。
