Details

Autor(en) / Beteiligte

• Marelli, Elena
• Lyu, Jike
• Morin, Mickaël
• Leménager, Maxime
• Shang, Tian
• Yüzbasi, N. Sena
• Aegerter, Dino
• Huang, Jinzhen
• Daffé, Niéli D
• Clark, Adam H
• Sheptyakov, Denis
• Graule, Thomas
• Nachtegaal, Maarten
• Pomjakushina, Ekaterina
• Schmidt, Thomas J
• Krack, Matthias
• Fabbri, Emiliana
• Medarde, Marisa

Titel

Cobalt-free layered perovskites RBaCuFeO (R = 4f lanthanide) as electrocatalysts for the oxygen evolution reaction

Ist Teil von

• EES catalysis, 2024-01, Vol.2 (1), p.335-35

Erscheinungsjahr

2024

Link zum Volltext

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• Co-based perovskite oxides are intensively studied as promising catalysts for electrochemical water splitting in an alkaline environment. However, the increasing Co demand by the battery industry is pushing the search for Co-free alternatives. Here we report a systematic study of the Co-free layered perovskite famil y RBaCuFeO 5+ δ (R = 4f lanthanide), where we uncover the existence of clear correlations between electrochemical properties and several physicochemical descriptors. Using a combination of advanced neutron and X-ray synchrotron techniques with ab initio DFT calculations we demonstrate and rationalize the positive impact of a large R ionic radius in their oxygen evolution reaction (OER) activity. We also reveal that, in these materials, Fe 3+ is the transition metal cation the most prone to donate electrons. We also show that similar R 3+ /Ba 2+ ionic radii favor the incorporation and mobility of oxygen in the layered perovskite structure and increase the number of available O diffusion paths, which have an additional, positive impact on both, the electric conductivity and the OER process. An unexpected result is the observation of a clear surface reconstruction exclusively in oxygen-rich samples ( δ > 0), a fact that could be related to their superior OER activity. The encouraging intrinsic OER values obtained for the most active electrocatalyst (LaBaCuFeO 5.49 ), together with the possibility of industrially producing this material in nanocrystalline form should inspire the design of other Co-free oxide catalysts with optimal properties for electrochemical water splitting. O K-edge XAS measurements reveal a surface reconstruction in RBaCuFeO 5+ δ layered perovskites when δ > 0. Oxygen excess, together with some degree of A-site cation intermixing, appears to control the OER activity in these Co-free electrocatalysts.