Balancing the Surface Reconstruction of Spinel Oxides for Efficient Oxygen Evolution Reaction

Transition metal compounds usually suffer from dynamic surface reconstruction with the electrocatalytic oxygen evolution reaction (OER). However, how to modulate the reconstruction to simultaneously achieve high activity and stability remains a grand challenge. Herein, we report a dynamic manipulation of the surface reconstruction to break the activity-stability trade-off in the spinel cobalt oxides through an introduction of an oxygen vacancy and doped metal element. The combined operando spectra investigations and theoretical calculations disclose that oxygen vacancies and Fe dopants synergistically elevate the Co d-band center and the O p-band center, manipulating the occurrence of surface transformation into active Fe-doped CoOOH (Fe-CoOOH) with optimized *O adsorption. The dynamically generated Fe vacancies during the OER suppress excessive reconstruction by downshifting the d-band center of Co, thereby stabilizing the catalyst. This work provides an alternative way to design more active and stable transition-metal-compound-based electrocatalysts for OER catalysis.