Mn- or Cu- substituted LaFeO<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si4.svg"><mml:msub><mml:mrow/><mml:mn>3</mml:mn></mml:msub></mml:math>-based three-way catalysts: Highlighting different catalytically operating modes of La<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si7.svg"><mml:msub><mml:mrow/><mml:mn>0.67</mml:mn></mml:msub></mml:math>Fe<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si8.svg"><mml:msub><mml:mrow/><mml:mn>0.8</mml:mn></mml:m

Nandi, Shreya; Wu, Jiang; Simon, Pardis; Nuns, Nicolás; Trentesaux, Martine; Tougerti, Asma; Fonda, Emiliano; Girardon, Jean‐Sébastien; Paul, Jean‐François; Mamède, Anne-Sophie; Berrier, Élise

doi:10.1016/j.apcatb.2021.120330

Cited by 21 publications

(1 citation statement)

References 55 publications

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“…Correspondingly, an obvious shift of Fe 2p 3/2 peak to higher binding energy from 709.7 eV of La 1.03 FeO 3 to 710.1 eV of La 0.97 FeO 3 can be noted (Fig. 2b ), suggesting that reduction of La content could induce improved valence state of Fe cations to maintain the charge balance in the oxides 33 , 34 . Overall, the above results illustrate that engineering the La concentration at A-site of perovskite ferrites is effective to alter chemical state of lattice oxygen, which is expected to exert great influence to the redox activity.…”

Section: Resultsmentioning

confidence: 87%

Subsurface A-site vacancy activates lattice oxygen in perovskite ferrites for methane anaerobic oxidation to syngas

He,

Wang,

et al. 2024

Nat Commun

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Tuning the oxygen activity in perovskite oxides (ABO3) is promising to surmount the trade-off between activity and selectivity in redox reactions. However, this remains challenging due to the limited understanding in its activation mechanism. Herein, we propose the discovery that generating subsurface A-site cation (Lasub.) vacancy beneath surface Fe-O layer greatly improved the oxygen activity in LaFeO3, rendering enhanced methane conversion that is 2.9-fold higher than stoichiometric LaFeO3 while maintaining high syngas selectivity of 98% in anaerobic oxidation. Experimental and theoretical studies reveal that absence of Lasub.-O interaction lowered the electron density over oxygen and improved the oxygen mobility, which reduced the barrier for C-H bond cleavage and promoted the oxidation of C-atom, substantially boosting methane-to-syngas conversion. This discovery highlights the importance of A-site cations in modulating electronic state of oxygen, which is fundamentally different from the traditional scheme that mainly credits the redox activity to B-site cations and can pave a new avenue for designing prospective redox catalysts.

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Section: Resultsmentioning

confidence: 87%