In this paper, we report on the preparation and catalysis of a bifunctional molecular catalyst (Fe[Pc(I)₄]+Ni[Pc(I)₄]@NC_PDI) for oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) in rechargeable Zn-air batteries. This catalyst is prepared by self-assembling tetraiodo metal phthalocyanines (Fe[Pc(I)₄] and Ni[Pc(I)₄]) on a 2D N-doped carbon material (NC_PDI) through π-π interactions. The introduction of iodine groups in the edge of phthalocyanines controls the density of electron cloud and electrostatic potential around Fe-N/Ni-N sites and constructs a built-in electric field that facilitates directional transport of charges, enhancing the catalytic activity of the catalyst. Density functional theory (DFT) calculations support this mechanism by showing a reduced energy barrier for the ORR rate-determining step (RDS). The Fe[Pc(I)₄]+Ni[Pc(I)₄]@NC_PDI exhibits excellent performance outperforming 20 wt% Pt/C and single-molecule self-assembled Fe[Pc(I)₄]@NC_PDI and Ni[Pc(I)₄]@NC_PDI, with a half-wave potential of E_1/2 = 0.940 V in the ORR process under alkaline condition. During the OER process, Fe[Pc(I)₄]+Ni[Pc(I)₄]@NC_PDI exhibited a low overpotential of 298 mV at 10 mA cm⁻² under the alkaline condition, which is much better than RuO₂, Fe[Pc(I)₄]@NC_PDI and Ni[Pc(I)₄]@NC_PDI. The catalyst also demonstrates excellent catalysis and durability in rechargeable Zn-air batteries. This work provides a simple and specific method to develop efficient multifunctional molecular electrocatalysts.

本文报道了双功能分子催化剂（Fe[ Pc (I) ₄ ]+Ni[ Pc (I) ₄ ]@NC _PDI ）的制备及其催化氧还原反应（ORR）和析氧反应（ OER）可充电锌空气电池。该催化剂是通过四碘金属酞菁（Fe[ Pc (I) ₄ ]和Ni[ Pc (I) ₄ ]）通过π-π相互作用在2D N掺杂碳材料（NC _PDI ）上自组装而制备的。在酞菁边缘引入碘基团控制了Fe-N/Ni-N位点周围的电子云密度和静电势，并构建了有利于电荷定向传输的内置电场，增强了催化剂的催化活性。密度泛函理论 (DFT) 计算显示 ORR 速率决定步骤 (RDS) 的能垒降低，从而支持了这一机制。 Fe[ Pc (I) ₄ ]+Ni[ Pc (I) ₄ ]@NC _PDI表现出优于 20 wt% Pt/C 和单分子自组装 Fe[ Pc (I) ₄ ]@NC _{PDI 的}优异性能， Ni[ Pc (I) ₄ ]@NC _PDI ，在碱性条件下ORR过程中半波电位为E _1/2 = 0.940 V。 在OER过程中，Fe[ Pc (I) ₄ ]+Ni[ Pc (I) ₄ ]@NC _PDI在碱性条件下在10 mA cm ^-2下表现出298 mV的低过电势，远优于RuO ₂ 、Fe[ Pc (I) ₄ ]@NC _PDI和 Ni[ Pc (I) ₄ ]@NC _PDI 。该催化剂在可充电锌空气电池中也表现出优异的催化作用和耐久性。这项工作为开发高效的多功能分子电催化剂提供了一种简单而具体的方法。