Highly Disordered Fe-Doped CeO₂ with Oxygen Vacancies Facilitates Electrocatalytic Water Oxidation

Abstract

The practical application of electrocatalytic water splitting is hindered by the sluggish anodic oxygen evolution reaction (OER), where the exploration of efficient and stable electrocatalysts toward water oxidation remains a great challenge. Herein, we report an active iron-doped ceria (FeO x /CeO2) catalyst with a highly disordered feature decorated on three-dimensional (3D) nickel foam, which can directly serve as the superior OER electrode in alkaline media. The highly disordered Fe-doped CeO2 catalyst displays remarkable OER performance with a low overpotential of 252 mV to achieve 10 mA cm–2, a small Tafel slope of 45 mV dec–1, and long-term durability for at least 48 h with a stable structure. The superior OER activity of FeO x /CeO2 is attributed to the lattice oxygen activation mechanism facilitated by its disordered structure as well as the high electrochemical surface area. This study provides valuable insights into the rational design of efficient OER catalysts through tailoring the catalyst structure and reaction pathway.

Heterometal Dopant Changes the Mechanism of Proton-Coupled Electron Transfer at the Polyoxovanadate-Alkoxide Surface

“…The observation of the formation of an O-atom defect at a vanadium center positioned cis to the titanium dopant is significant. Theoretical investigations interrogating defect formation in doped metal oxides reveal preferential reduction adjacent to the heterometal. − This observation is justified by the fact that the heterometal weakens adjacent metal oxygen bonds. It is important to recall that in the case of these low-valent POV-alkoxide clusters, bridging sites are saturated with alkoxide ligands, rendering them inert to H-atom-transfer reactions.…”