Hetero‐Atomic Pairs with a Distal Fe3+‐Site Boost Water Oxidation

• Published in: Angewandte Chemie Vol. 134; no. 48
• Main Authors: Zhu, Yanping, Chen, Gao, Chu, You‐Chiuan, Hsu, Chia‐Shuo, Wang, Jiali, Tung, Ching‐Wei, Chen, Hao Ming
• Format: Journal Article
• Language: English
• Published: Weinheim Wiley Subscription Services, Inc 25.11.2022
• Subjects: Atomic interactions; Chemistry; Electrocatalysts; Hetero-Atomic Pairs; Heterogeneity; Iron; Lewis Acidic Fe3; Metal-Support Interaction; Operando Characterization; Oxidation; Oxygen; Oxygen evolution reactions; Oxygen production; Phosphides; Substrates; Tungsten; Water Oxidation
• ISSN: 0044-8249; 1521-3757
• DOI: 10.1002/ange.202211142

The hetero‐atomic interaction has been the subject of many investigations, due to their heterogeneity, the individual roles of the atoms are still difficult to realize. Herein, an electrocatalyst with a hetero‐atomic pair confined on a tungsten phosphide (WP) substrate so that the Fe3+‐site of the pair is distal to the surface is shown to deliver an extremely low overpotential of 192 mV at 10 mA cm−2 and one of the highest oxygen production turnover frequencies (TOF) of 2.1 s−1 at 300 mV under alkaline environment for the oxygen evolution reaction (OER). Operando characterization shows the Lewis acidic Fe3+ site boosts a large population of Co4+/3+ and the deprotonation of coordinated water, allowing simultaneously enhanced electron‐transfer as well as the proton‐transfer. A significant contribution from the WP substrate modulates the order of hydroxide transfer in the pre‐equilibrium step (PES) and rate‐determining‐step (RDS), leading to a remarkable OER performance. A Co−Fe hetero‐atomic pair, bound to a tungsten phosphide (WP) substrate so that the Lewis acidic Fe center is distal to the surface, boosted water oxidation. A significant contribution from the WP substrate modulated the order of hydroxide transfer. The system offers insights into bimetallic oxygen evolution reaction (OER) electrocatalytic systems and provides a model of in situ/operando investigations on the mechanistic understanding as well as future catalysts design.