Oxygen reactivity regulation via double‐exchange interaction for enhanced water oxidation

Abstract

Abstract The sluggish kinetics of anodic oxygen evolution reaction (OER) largely impedes the energy conversion efficiency in electrolytic industries. Fundamentally, the OER process is governed by the chemical reactivity of oxygen intermediates. Here, we demonstrate an effective approach to regulate the oxygen reactivity through the double‐exchange interaction (DEI) towards OER activity improvement, using Ti‐substituted pyrochlore ruthenate Y2Ru2−xTixO7 as model catalyst. We unveil that DEI‐induced electron hopping in asymmetric Ru‐O‐Ti backbone enables the charge depletion in Ru active center to tune on the oxygen activation by ligand hole introduction. In addition, the ferromagnetic nature of DEI constructs a spin‐selected channel for charge transport to govern the spin state in oxygen intermediates. Such comprehensive manipulation of oxygen reactivity substantially facilitates the nucleophilic attack process during O–O coupling as rate‐determining step, lowering the energy barrier to improve the intrinsic OER activity.

Keywords

• double‐exchange interaction
• oxygen evolution reaction
• oxygen reactivity
• ruthenate
• spin polarization