How Reconstruction‐Driven Mechanism Switching Controls Metal Polyphthalocyanines Catalyst Stability
Qianglong Qi, Wenqing Guan, Yunhai Zi, Chenxu Zhang, Jue Hu
Abstract
Abstract During the oxygen evolution reaction (OER), the dynamic reconstruction of electrocatalysts is a key factor in regulating catalytic performance. However, current research has foucused on documenting the phenomenon of electrocatalyst reconstruction, while critically overlooking the intrinsic connection between its dynamic reconstruction and catalytic stability. Herein, using metallic polyphthalocyanines (M‐PPc, M═Fe/Co/Ni/Mn/Cu) as model, it is first revealed that dynamic reconstruction of active sites with different metal centers not only regulates active phase structure, but also drives directional change reaction mechanisms and directly determine stability differences. Specifically, in‐situ Raman reveals weak metal─nitrogen bond facilitate rapid metal─oxygen bond formation, enabling Fe‐PPc and Co‐PPc to form phases of FeOOH or CoOOH at low potentials, while Ni‐PPc and Cu‐PPc reconstruction requires higher potentials due to stronger M─N bonds. Fe‐PPc and Co‐PPc undergo a transition from the initial intramolecular oxygen coupling mechanism (IOM) to the lattice oxygen mechanism (LOM), while Ni‐PPc and Mn‐PPc switch from IOM to the adsorbate evolution mechanism (AEM). The direction of this mechanistic transition directly determines the different expression of catalytic stability. Fe‐PPc achieves stable operation for 150 h at 1000 mA cm −2 , while Ni‐PPc, which transitions to the AEM pathway, exhibits significant stability degradation.