Breaking the chlorine and oxygen evolution scaling relation via the selective shielding effect of oxophilic Ti sites

Abstract

To overcome the selectivity–stability trade-offs in acidic chlor-alkali electrolysis, we develop Co₃O₄/TiO₂ core–shell nanowires. The oxophilic TiO₂ shell creates a “shielding effect” that blocks H₂O access to Co₃O₄, effectively decoupling chlorine and oxygen evolution. This architecture shows a remarkably low overpotential (310 mV) and long-term stability, presenting a powerful paradigm for selective electrocatalyst design.