山东理工大学《JCIS》：聚卟啉锰与3D N掺杂石墨烯之间的Mn-N5结构可提高双功能氧催化性能

方案1. The preparation process of PPorMn and PPorMn/3D-NG.

图1. The characterization of samples (a) TEM; (b) HRTEM of PPorMn; (c) the inverse FFT image of (110) plane. (d) Lattice spacing measurement. (e-h) HAADF-STEM of PPorMn and Mapping of C, N, Mn; (i) UV–Vis of TcPorMn, and PPorMn; (j) FT-IR; (k) TG (l) 1H NMR of PPorMn (solvent as DMSO‑d6); (m) Nitrogen adsorption–desorption isotherms and pore-size distribution plots for the samples; (n) PXRD.

图2. The characterization of PPorMn/3D-NG and PPorMn/3D-G. (a) SEM images; (b, c) TEM and HR-TEM images of PPorMn/3D-NG; (d) SAED; (e) HAADF-STEM and mapping of C, N, and Mn elements; (f) UV–Vis diffuse reflectance absorption spectra; (g) Raman spectra of PPorMn/3D-NG, PPorMn/3D-G, and 3D-NG; (h) The XRD of PPorMn/3D-NG and 3D-NG; (i) BET surface area; (j) Pore size distribution; (k) X-ray photoelectron spectroscopy (XPS) full spectra; High-resolution X-ray photoelectron spectroscopy of PPorMn and PPorMn/3D-NG:, (l) N 1 s, (m) N species content, and (n) Mn 2p.

图3. The ORR and OER test performance evaluation. (a) LSV curves; (b) Tafel curves; (c) The number of electrons transferred and H2O2 yields got from RRDE; (d) The poisoning experiments for PPorMn/3D-NG (O2-saturated 0.1 M KOH) with and without 0.05 M KSCN; (e) OER LSV curves; (f) The ADT curve; (g) ΔE calculation of ORR and OER; (h) Comparison of E1/2, n number, Ej=10, ΔE, Tafel (ORR), Tafel (OER) of PPorMn/3D-NG and the other oxygen catalysts in literature.

图4. The DFT calculations of samples (a) The energy levels of the HOMO and LUMO of TcPorMn and PPorMn; (b) Mn–N4 site and (c) Mn–N5 site models; (d, e) Oxygen adsorption intermediates models (Mn–N5 site); (f, g) The calculated free-energy evolution diagram for ORR of samples; (h) DOS of TcPorMn and PPorMn; (i, j) Charge density difference of PPorMn/3D-G (Mn–N4 site) and PorMn/3D-NG (Mn–N5 site).

图5. The Zn-air batteries performance evaluation (a) Model diagram of Zn-air battery; (b) The discharge curves of ZABs; (c) The charge and discharge polarization curve of Zn-air battery; (d) Specific capacity of ZABs (∼10 mA cm−2); (e) The cyclic stability performance curve of ZAB at 10 mA cm−2; (f) Schematic diagram of F-ZABs; (g) The power density; (h) Galvanostatic discharge and charge curves of Zn-air battery with the PPorMn/3D-NG cathodes under bending.

本研究成功合成了具有高热稳定性和较小 HOMO-LUMO 能级间隙的全共轭 PPorMn，并将其与 3D-NG 固定在一起，形成具有 Mn-N5 活性中心的 PPorMn/3D-NG。Mn-N5 结构的创新构建提高了氧催化性能。PPorMn/3D-NG 具有显著的氧催化性能，与 RHE 相比，E1/2为0.90 V。PPorMn/3D-NG 还具有良好的 OER 性能，在10mA cm-2 的电流密度下，其电位较低（与 RHE相比，Ej=10为1.59 V）。它具有良好的双功能催化性能（△E = 0.69 V）。在l-ZABs和F-ZABs中，它还表现出较高的功率密度和循环稳定性。DFT 计算表明，锰-吡啶N桥键作为 “电子泵”，不断将电子从三维-NG转移到锰-N5 位点，从而提高了 PPorMn/3D-NG 的氧催化活性。PPorMn/3D-NG 的催化性能优于之前的研究。这项工作进一步探索了 Mn-N5 结构的电子传递机制，从而为设计高效的双功能氧催化剂提供了支持。它还提出了利用 PPorMn/3D-NG 提高氧催化剂性能和扩大其在氧催化转化装置中应用的可行策略。