Controlled lattice oxygen redox in Ce-doped CoFe-LDH for stable oxygen evolution

Ce–O v coupling enables site-differentiated mixed AEM/LOM pathways. • CeCoFe-LDH delivers 230 m V at 10 mA cm −2 and a low Tafel slope of 27.9 mV dec −1 . • Controlled lattice oxygen redox suppresses Co/Fe dissolution and deep surface reconstruction. • CeCoFe-LDH operates stably for 1500 h at 500 mA cm −2 under industrial conditions. • Anion-exchange-membrane water electrolysis reaches 1.71 V at 1 A cm −2 for 220 h at 60 °C. Achieving both high OER activity and long-term stability at industrial current densities remains a key challenge for green hydrogen production by water electrolysis. Herein, we report a CeCoFe-layered double hydroxide (LDH) catalyst designed to balance lattice oxygen activation with structural stability under industrial-current-density OER conditions. The synergistic interaction between doped Ce and synthesis-induced oxygen vacancies (O v ) preferentially activates adjacent lattice oxygen sites, thereby introducing a lattice oxygen mechanism (LOM) channel while retaining partial metal-site adsorbate evolution mechanism (AEM) activity. As a result, the catalyst delivers an overpotential of 230 m V at 10 mA cm −2 and a Tafel slope of 27.9 mV dec −1 , demonstrating excellent OER performance. When assembled as the anode catalyst in an anion exchange membrane water electrolyzer, CeCoFe-LDH achieves a cell voltage of only 1.71 V at 1 A cm −2 and 60 °C, with stable operation for 220 h. Experimental characterization and theoretical calculations reveal that Ce-O v coupling upshifts the O 2 p band center while moderately weakening the Co O bonds, thereby facilitating controlled lattice oxygen redox participation. Meanwhile, residual AEM activity on Co sites, together with Ce-mediated structural stabilization, prevents excessive lattice oxygen consumption and suppresses Co/Fe dissolution and deep surface reconstruction, allowing stable OER operation for 1500 h at 500 mA cm −2 . These findings highlight a rational strategy for durable high-performance OER electrocatalysts for industrial applications. Download: Download high-res image (212KB) Download: Download full-size image