Steering moderated intermediate adsorption and lattice oxygen activation via Ce and B co-doped CuCo catalysts for...

Developing non-precious-metal electrocatalysts with concurrent high activity and durability remains a grand challenge for the alkaline oxygen evolution reaction (OER). Herein, we rationally design and develop a cerium and boron co-doped ultrathin copper-cobalt carbonate hydroxide nanosheet (B-Ce-CuCo) electrocatalyst. The introduced Ce and B achieve a rare collaboration between the adsorbate evolution mechanism (AEM) and lattice oxygen oxidation mechanism (LOM) by optimizing oxygen-containing intermediate adsorption, increasing stabilized oxygen vacancies, and activating lattice oxygen. The optimized catalyst exhibits an ultralow overpotential of 208 mV at 10 mA cm^-2 with a Tafel slope of 42.77 mV dec^-1 and exceptional stability over 1000 h at 50 mA cm^-2. Theoretical calculations reveal that Ce modulates the electronic structure by shifting unoccupied Co/O states toward the Fermi level, optimizing the adsoprtion of oxygenated intermediate and boosting the AEM pathway. Both Ce and B promote oxygen vacancy generation, while B stabilizes these vacancies to activate lattice oxygen, enabling extensive LOM participation via Co(IV)O and *OO intermediates. ¹⁸O-labeled differential electrochemical mass spectrometry (DEMS) directly identifies the coexistence of AEM and LOM pathways. This synergy reduces the AEM and LOM energy barriers to 0.39 eV and 0.58 eV, respectively, establishing a fundamentally new paradigm for designing high-performance electrocatalysts via dual-element doping.