Correlating the electronic structure of perovskite La1−Sr CoO3 with activity for the oxygen evolution reaction: The critical role of Co 3d hole state

Shen, Zechao; Qu, Mei; Shi, Jueli; Oropeza, Freddy E.; O’Shea, Víctor A. de la Peña; Gorni, Giulio; Tian, Cuicui; Hofmann, Jan P.; Cheng, Jun; Li, Jun; Zhang, Kelvin H. L.

doi:10.1016/j.jechem.2021.06.032

Cited by 59 publications

(40 citation statements)

References 66 publications

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“…The experimental results demonstrate that the BCFI has good OER catalytic effect, and the doping of 5% Ir can significantly improve the catalytic activity. BCFI also exhibits excellent OER activity compared with some Co‐based perovskites, such as (Ba 0.5 Sr 0.5 ) 1– x Co 0.8 Fe 0.2 O 3– δ (about 380 mV, 88 mV·dec –1 ), [ 24 ] monolithic perovskite NF/LaCo 0.8 Fe 0.2 O 3 (350 mV, 59 mV·dec –1 ), [ 25 ] La 1– x Sr x CoO 3 (>370 mV, 85 mV·dec –1 ) [ 26 ] and Mn‐Ni dual doped ABO 3 ‐type LaMn x Ni y Co z O 3 (370 mV, 80.19 mV·dec –1 ). [ 27 ] Furthermore, compared with the recent reports about perovskite catalysts based on transition metals (Table S2), BCFI still presents remarkable catalytic performance.…”

Section: Resultsmentioning

confidence: 99%

Iridium‐Doped 10H‐Phase Perovskite BaCo₀_.₈Fe₀_.₁₅Ir₀_.₀₅O₃_–δ as an Efficient Oxygen Evolution Reaction Catalyst

Liu

Luo

et al. 2022

Chin. J. Chem.

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Comprehensive Summary Designing low‐cost and high‐performance catalysts of electrocatalytic oxygen evolution reaction (OER) has always been one of the hot topics in current research. Hexagonal perovskite materials show great application potential in this field. Here, we synthesized 5% Iridium (Ir)‐doped hexagonal phase perovskite BaCo0.8Fe0.15Ir0.05O3–δ (BCFI). Using the Rietveld method to refine the structure, combining with the spherical aberration corrected high‐angle annular dark‐field scanning transmission electron microscopy (HAADF‐STEM) atomic imaging, we found that BCFI is a ten‐layer hexagonal (10H) structure, which belongs to the P true 6¯m2 space group. In addition, BCFI shows excellent OER catalytic effect and good stability in 1 mol/L KOH solution, and the overpotential reaches 294 mV at a current density of 10 mA cm–2. The reduction of Cobalt (Co) valence state induced by Ir doping significantly enhances the OER activity of BCFI. Meanwhile, density functional theory (DFT) calculations show that the 2p‐band center of oxygen (O) in BCFI is closer to the Fermi level than that in undoped BaCo0.8Fe0.2O3‐δ (BCF), which is beneficial to the OER. This work reveals a novel 10H‐BCFI material with excellent OER performance, and provides a basis for the design of hexagonal perovskite materials in OER and other energy conversion fields.

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Section: Resultsmentioning

confidence: 99%

Iridium‐Doped 10H‐Phase Perovskite BaCo₀_.₈Fe₀_.₁₅Ir₀_.₀₅O₃_–δ as an Efficient Oxygen Evolution Reaction Catalyst

Liu

Luo

et al. 2022

Chin. J. Chem.

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“…It is always necessary to understand the relationship between the electronic structure and the electrocatalytic activity of a catalyst, which is crucial for further advancements . We examined the electronic properties of Co 3 O 4 and Co 3 O 4 |CoP by using both the Tauc plots that were obtained from ultraviolet–visible diffuse reflectance spectroscopy (UV-DRS) and XPS valence band (VB) spectroscopy.…”

Section: Resultsmentioning

confidence: 99%

“…It is always necessary to understand the relationship between the electronic structure and the electrocatalytic activity of a catalyst, which is crucial for further advancements. 35 We examined the electronic properties of Co 5b). The Role of the Binder in the Catalyst Ink Preparation.…”

Section: ■ Experimental Sectionmentioning

confidence: 99%

Co₃O₄|CoP Core–Shell Nanoparticles with Enhanced Electrocatalytic Water Oxidation Performance

Malik

Sadhanala

Sun

et al. 2022

ACS Appl. Nano Mater.

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Developing high performance, cost-effective, and durable electrocatalysts that must be derived from non-noble metals is crucial for alkaline oxygen evolution reaction (OER). OER, which takes place at the anode, is accepted as a major obstacle for commercialization due to its sluggish kinetics. In this study, a two-step synthesis method, such as a hydrothermal process followed by the annealing of the reactants in an Ar-filled Swagelok cell, is briefly described to obtain a cubic type of Co3O4 core and CoP shell. As a result of synergy, Co3O4|CoP demonstrates an onset overpotential of 280 mV and reaches a current density of 10 mA cm–2 at an overpotential of 320 mV in an alkaline medium (pH = 13.5). The electronic property of the heterojunction is verified by the Tauc plot and valence band XPS. The band structure indicates that Co3O4|CoP exhibits a more metallic character than pristine Co3O4 due to the fact that the charge transfer process is faster. Further, the introduction of CoP significantly modifies the redox processes of Co3O4, which we examined with the help of large amplitude alternating current voltammetry (LA-ACV). The mechanistic study suggests that “catalytic performance is directly related to the peak-to-peak current density” of the redox process of the combined catalyst and reactant.

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“…Utilizing alkaline electrolytes is a feasible solution to use earth-abundant 3 d transition metal oxides as electrocatalysts because of their structural and chemical stability. As catalysts for alkaline water electrolysis, perovskite-type oxides such as La 1– x Sr x CoO 3−δ , have been reported to show high OER activity. Recently, it has been reported that Fe-doped Ni and Co oxides exhibit superior electrochemical performance under rational design. − However, the electrode/electrolyte interface reaction mechanism, which is necessary to understand the origin of the excellent catalytic performance, has not been fully clarified.…”

Section: Introductionmentioning

confidence: 99%

State of the Active Site in La_1–xSr_xCoO_3−δ Under Oxygen Evolution Reaction Investigated by Total-Reflection Fluorescence X-Ray Absorption Spectroscopy

Ren

Oyama

Uchiyama

et al. 2022

ACS Appl. Energy Mater.

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Recent developments in hydrogen energy devices have furthered the research on sustainable hydrogen production methods. Among these, the water splitting process has been considered a promising hydrogen production method, particularly, in alkaline media. The lack of information on the reaction active sites under the conditions of the oxygen evolution reaction (OER) hinders establishing guidelines for catalyst development. In the case of powder catalysts, many operando techniques also measure bulk information, and therefore, extracting information on the reaction active sites is challenging. Accordingly, film electrodes were used in this study, and the electrochemical performance and reaction kinetics of perovskite-type La1–x Sr x CoO3−δ films as OER catalysts synthesized by pulsed laser deposition were investigated. By combining ex situ X-ray absorption spectroscopy (XAS) and operando total-reflection fluorescence X-ray absorption spectroscopy (TRF-XAS), we succeeded in observing a significant oxidation state change on the surface of La0.6Sr0.4CoO3−δ, which indicated that the active surface sites were formed upon applying the OER potential. This surface reconstruction resulted in numerous active sites at the reaction interface, thereby enhancing the OER activity. This study provides definitive evidence for the surface reconstruction of OER catalysts, which enhances the fundamental understanding of OER catalyst behaviors, and can inspire the design of active OER catalysts by suitable surface modulation.

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Correlating the electronic structure of perovskite La1−Sr CoO3 with activity for the oxygen evolution reaction: The critical role of Co 3d hole state

Cited by 59 publications

References 66 publications

Iridium‐Doped 10H‐Phase Perovskite BaCo₀_.₈Fe₀_.₁₅Ir₀_.₀₅O₃_–δ as an Efficient Oxygen Evolution Reaction Catalyst

Iridium‐Doped 10H‐Phase Perovskite BaCo₀_.₈Fe₀_.₁₅Ir₀_.₀₅O₃_–δ as an Efficient Oxygen Evolution Reaction Catalyst

Co₃O₄|CoP Core–Shell Nanoparticles with Enhanced Electrocatalytic Water Oxidation Performance

State of the Active Site in La_1–xSr_xCoO_3−δ Under Oxygen Evolution Reaction Investigated by Total-Reflection Fluorescence X-Ray Absorption Spectroscopy

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Correlating the electronic structure of perovskite La1−Sr CoO3 with activity for the oxygen evolution reaction: The critical role of Co 3d hole state

Cited by 59 publications

References 66 publications

Iridium‐Doped 10H‐Phase Perovskite BaCo0.8Fe0.15Ir0.05O3–δ as an Efficient Oxygen Evolution Reaction Catalyst

Iridium‐Doped 10H‐Phase Perovskite BaCo0.8Fe0.15Ir0.05O3–δ as an Efficient Oxygen Evolution Reaction Catalyst

Co3O4|CoP Core–Shell Nanoparticles with Enhanced Electrocatalytic Water Oxidation Performance

State of the Active Site in La1–xSrxCoO3−δ Under Oxygen Evolution Reaction Investigated by Total-Reflection Fluorescence X-Ray Absorption Spectroscopy

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Iridium‐Doped 10H‐Phase Perovskite BaCo₀_.₈Fe₀_.₁₅Ir₀_.₀₅O₃_–δ as an Efficient Oxygen Evolution Reaction Catalyst

Iridium‐Doped 10H‐Phase Perovskite BaCo₀_.₈Fe₀_.₁₅Ir₀_.₀₅O₃_–δ as an Efficient Oxygen Evolution Reaction Catalyst

Co₃O₄|CoP Core–Shell Nanoparticles with Enhanced Electrocatalytic Water Oxidation Performance

State of the Active Site in La_1–xSr_xCoO_3−δ Under Oxygen Evolution Reaction Investigated by Total-Reflection Fluorescence X-Ray Absorption Spectroscopy