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Free keywords:
electronic structure, hybrid construction, lattice-oxygen activation, oxygen evolution reaction, synergistic effects, Chemical activation, Electrocatalysts, Energy conversion, Iron compounds, Lanthanum compounds, Metals, Oxygen evolution reaction, Perovskite, Potassium hydroxide, Ruthenium compounds, Strontium compounds, Energy applications, Energy conversion technologies, High catalytic performance, Hybrid construction, Oxygen evolution reaction (oer), Perovskite phase, Proof of concept, Self-assembly method, Catalyst activity
Abstract:
The oxygen evolution reaction (OER) is pivotal in multiple gas-involved energy conversion technologies, such as water splitting, rechargeable metal–air batteries, and CO2/N2 electrolysis. Emerging anion-redox chemistry provides exciting opportunities for boosting catalytic activity, and thus mastering lattice-oxygen activation of metal oxides and identifying the origins are crucial for the development of advanced catalysts. Here, a strategy to activate surface lattice-oxygen sites for OER catalysis via constructing a Ruddlesden–Popper/perovskite hybrid, which is prepared by a facile one-pot self-assembly method, is developed. As a proof-of-concept, the unique hybrid catalyst (RP/P-LSCF) consists of a dominated Ruddlesden–Popper phase LaSr3Co1.5Fe1.5O10-δ (RP-LSCF) and second perovskite phase La0.25Sr0.75Co0.5Fe0.5O3-δ (P-LSCF), displaying exceptional OER activity. The RP/P-LSCF achieves 10 mA cm−2 at a low overpotential of only 324 mV in 0.1 m KOH, surpassing the benchmark RuO2 and various state-of-the-art metal oxides ever reported for OER, while showing significantly higher activity and stability than single RP-LSCF oxide. The high catalytic performance for RP/P-LSCF is attributed to the strong metal–oxygen covalency and high oxygen-ion diffusion rate resulting from the phase mixture, which likely triggers the surface lattice-oxygen activation to participate in OER. The success of Ruddlesden–Popper/perovskite hybrid construction creates a new direction to design advanced catalysts for various energy applications. © 2020 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
