Dynamic active site evolution and stabilization of core-shell structure electrode for oxygen evolution reaction

In robust oxygen evolution reaction (OER), the irregular transition metal atom migration at the catalyst electrolyte interface disrupts the durability of the surface electronic structure. Herein, we induce the orderly migration of metal elements from core to the surface of NiCo2O4@FeO(x )model electrode to overcome the instable element balance between metal dissolution and deposition. In OER working potential, the driving force of concentration gradient on Ni element migration can be strengthen by the shuttle of miniscule oxygen intermediates in the bulk phase, which promotes the changes of metal species (Ni or Co) and migration direction, further optimizing the surface oxide state. Consequently, the resulting electrode would stabl react over 50,000 CV cycles as well as continued test for 300 h at current density of 100 mA cm(-2).