Intrinsic Electrocatalytic Activity for Oxygen Evolution of Crystalline 3d‐Transition Metal Layered Double Hydroxides

• Published in: Angewandte Chemie International Edition Vol. 60; no. 26; pp. 14446 - 14457
• Main Authors: Dionigi, Fabio, Zhu, Jing, Zeng, Zhenhua, Merzdorf, Thomas, Sarodnik, Hannes, Gliech, Manuel, Pan, Lujin, Li, Wei‐Xue, Greeley, Jeffrey, Strasser, Peter
• Format: Journal Article
• Language: English
• Published: Germany Wiley Subscription Services, Inc 21.06.2021; John Wiley and Sons Inc
• Edition: International ed. in English
• Subjects: Catalysts; Cobalt; Crystal structure; Crystallinity; Electrocatalysts; electrochemical surface area; Electrochemistry; Electrolytes; hydrothermal synthesis; Hydroxides; Iron; Iron compounds; layered double hydroxides; Manganese; Nickel compounds; Oxygen; oxygen evolution reaction; Oxygen evolution reactions; Reaction centers; Transition metals; water splitting; oxygen evolution reaction; layered double hydroxides; hydrothermal synthesis; water splitting; electrochemical surface area
• ISSN: 1433-7851; 1521-3773; 1521-3773
• DOI: 10.1002/anie.202100631

Layered double hydroxides (LDHs) are among the most active and studied catalysts for the oxygen evolution reaction (OER) in alkaline electrolytes. However, previous studies have generally either focused on a small number of LDHs, applied synthetic routes with limited structural control, or used non‐intrinsic activity metrics, thus hampering the construction of consistent structure–activity‐relations. Herein, by employing new individually developed synthesis strategies with atomic structural control, we obtained a broad series of crystalline α‐MA(II)MB(III) LDH and β‐MA(OH)2 electrocatalysts (MA=Ni, Co, and MB=Co, Fe, Mn). We further derived their intrinsic activity through electrochemical active surface area normalization, yielding the trend NiFe LDH > CoFe LDH > Fe‐free Co‐containing catalysts > Fe‐Co‐free Ni‐based catalysts. Our theoretical reactivity analysis revealed that these intrinsic activity trends originate from the dual‐metal‐site nature of the reaction centers, which lead to composition‐dependent synergies and diverse scaling relationships that may be used to design catalysts with improved performance. Catalytic activities for oxygen evolution on crystalline 3d transition metal layered double hydroxides are derived using electrochemical surface area based normalization. Density functional calculations reveal a dual‐metal‐site feature of the reaction centers that provides opportunities to design new catalysts with improved performance.