Porous LaFeO3 nanofiber with oxygen vacancies as an efficient electrocatalyst for N2 conversion to NH3 under ambient conditions

Li, Chengbo; Ma, Dongwei; Mou, Shiyong; Luo, Yongsong; Ma, Benyuan; Lu, Siyu; Cui, Guanwei; Li, Quan; Liu, Qian; Sun, Xuping

doi:10.1016/j.jechem.2020.03.044

Cited by 98 publications

(48 citation statements)

References 65 publications

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“…In Table S5, Supporting Information, we also compared the NRR activities of all the samples in this work with those of other perovskite oxides in the literatures. [14][15][16][17][18][19] Our samples performed comparably to or better than those reported perovskite oxides except for LaCoO 3−δ that exhibited the highest NRR activities reported so far.…”

Section: Resultssupporting

confidence: 45%

A General Strategy to Boost Electrocatalytic Nitrogen Reduction on Perovskite Oxides via the Oxygen Vacancies Derived from A‐Site Deficiency

Chu

Liu

Zhu

et al. 2021

Advanced Energy Materials

119

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pressures (10-30 MPa), but also demands a large deal of H 2 mainly from natural gas reforming which causes abundant consumption of fossil fuels and huge CO 2 emissions. [3-6] As a result, for energy conservation and environmental protection, it is of crucial importance to explore a clean and sustainable route for NH 3 production. Electrocatalytic N 2 reduction reaction (NRR) under ambient conditions has been emerged recently as an attractive strategy for the green synthesis of NH 3 through utilizing inexhaustible N 2 and H 2 O. [7-12] However, due to the competition with H 2 evolution reaction (HER) and ultra-stable NN covalent triple bond, NRR suffers from unsatisfactory Faradaic efficiency (FE) and sluggish reaction kinetics. [13] It is of eager desire, but very challenging to develop selective and efficient electrocatalysts toward NRR that can inhibit the competitive HER and activate the N 2 molecule. Among various developed electrocatalysts, perovskite oxides have proven their great potential toward NRR because of their low cost, good adjustability in intriguing physicochemical properties, as well as economic and environmental friendliness. Typical examples include a few simple perovskite oxides, such as LaCoO 3 , LaCrO 3 , LaFeO 3 , La 2 Ti 2 O 7 , and Ce 1/3 NbO 3. [14-19] Although significant progress has been made, their NRR performance is still far from the requirements of commercial NH 3 synthesis. Most recently, several studies have shown that the electrocatalytic The electrocatalytic N 2 reduction reaction (NRR) under ambient conditions is an attractive strategy for green synthesis of NH 3. Due to the ultra-stable NN covalent triple bond, it is very challenging to develop highly selective and efficient electrocatalysts toward NRR. Here a general strategy to enhance the NRR activity through modulating A-site-deficiency-induced oxygen vacancies of perovskite oxides is reported. One successful example is La x FeO 3−δ (L x F, x = 1, 0.95, and 0.9) perovskite oxides with tunable oxygen vacancies that are directly proportional to the La-site deficiencies. As compared to the pristine LF, the L 0.95 F and L 0.9 F exhibit significantly improved NRR activities, which are positively correlated with the La-site deficiency and the amount of oxygen vacancies. Among them, the L 0.9 F delivers the best activity, with an NH 3 yield rate of 22.1 µg•h −1 •mg −1 cat. at −0.5 V and a Faradaic efficiency of 25.6% at −0.3 V, which are 2.2 and 1.6 times those of the pristine LF, respectively. Both experimental characterizations and theoretical calculations suggest that the enhanced NRR activity can be mainly attributed to the favorable merits produced by the oxygen vacancies: the promoted adsorption/activation of reaction species, and thus optimized reaction pathways. Application of this strategy to other perovskite oxides generates similarly successful results.

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Section: Resultssupporting

confidence: 45%

A General Strategy to Boost Electrocatalytic Nitrogen Reduction on Perovskite Oxides via the Oxygen Vacancies Derived from A‐Site Deficiency

Chu

Liu

Zhu

et al. 2021

Advanced Energy Materials

119

View full text Add to dashboard Cite

show abstract

“…In recent years, oxygen vacancies (OVs), [21–23] sulfur vacancies (SVs) [24,25] and nitrogen vacancies (NVs) [26,27] have been widely reported in catalytic reactions. Oxygen vacancies, as a common anion defect, can reduce the reaction activation energy barrier and play an important role in the process of electrocatalytic N 2 adsorption and activation [28,29] …”

Section: Figurementioning

confidence: 99%

WO₃ Rich in Oxygen Vacancies Through Ion‐Exchange Reaction for Enhanced Electrocatalytic N₂ Reduction to NH₃

Zhang

Jiang

et al. 2020

ChemCatChem

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Electrochemical route is an admirable strategy for N2 fixation to NH3, which can save more energy and reduce greenhouse gas emissions compared with the Haber‐Bosch process. However, it still suffers from extremely low ammonia yield for the lack of effective electrocatalysts and shows low Faraday efficiency due to competitive hydrogen evolution reaction (HER). Herein, we firstly synthesized needle‐like K0.33WO3.16 (K‐WO3) by molten salt method, then K0.33WO3.16 with surface defect structure (WO3‐OV) was successfully obtained through ion‐exchange of H+ and dehydration process. An obvious absorption enhancement in the near infrared region exhibited in UV‐vis absorption spectra and a significant ESR signal at g=2.003 proves the existence of O vacancies. The abundant oxygen vacancies ensure that Faraday efficiency of WO3‐OV gets improved to 25.45 % at −0.3 V (vs RHE), much superior to K‐WO3 (FE: 9.33 %). It is worth noting that defect‐rich WO3‐OV also shows high electrochemical stability.

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“…These materials only presented inferior performance when compared with La 0.8 Cs 0.2 Fe 0.8 Ni 0.2 O 3− δ and LaFeO 3 . Beyond the cation doping/substitution strategy, post‐treatment by annealing in a reductive atmosphere (5% H 2 /Ar) [ 121 ] or A‐site deficiency [ 26 ] can also create oxygen vacancies in LaFeO 3 and induce efficient NRR catalysis. Further theoretical studies demonstrated that the introduction of oxygen vacancies into LaFeO 3 could not only facilitate the adsorption and activation of the N 2 molecule, but also optimize the reaction pathways through intensifying the interactions between adsorbed species and unsaturated Fe sites.…”

Section: Electrocatalysis Of Nrrmentioning

confidence: 99%

Perovskite Oxides for Cathodic Electrocatalysis of Energy‐Related Gases: From O₂ to CO₂ and N₂

Zhang

Lü

et al. 2021

Adv Funct Materials

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The oxygen reduction reaction (ORR), carbon dioxide reduction reaction (CO2RR), and nitrogen reduction reaction (NRR) are important cathodic reactions for renewable fuel production and energy conversion technologies. However, the sluggish kinetics of these reactions hinders the practical applications of the relevant technologies. Perovskite oxides, a promising family of catalysts with great flexibility in composition and structure engineering, exhibit versatility in electrocatalysis of these reactions. In this review, beginning with a brief introduction on the fundamentals of ORR, CO2RR, and NRR, the mechanistic understanding of the electrocatalysis by perovskite oxides is discussed based on both molecular orbital and band theories. The recent advances of perovskite oxide‐based electrocatalysts for ORR, CO2RR, and NRR are then highlighted. Strategies for developing perovskite oxide‐based ORR catalysts are emphasized with representative examples, intending to draw on the experience of developing ORR catalysts to both CO2RR and NRR catalysts. Finally, perspectives on the perovskite oxide‐based electrocatalysis are discussed by paying particular attention to the practical applications and future development of perovskite oxide‐based catalysts.

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Porous LaFeO3 nanofiber with oxygen vacancies as an efficient electrocatalyst for N2 conversion to NH3 under ambient conditions

Cited by 98 publications

References 65 publications

A General Strategy to Boost Electrocatalytic Nitrogen Reduction on Perovskite Oxides via the Oxygen Vacancies Derived from A‐Site Deficiency

A General Strategy to Boost Electrocatalytic Nitrogen Reduction on Perovskite Oxides via the Oxygen Vacancies Derived from A‐Site Deficiency

WO₃ Rich in Oxygen Vacancies Through Ion‐Exchange Reaction for Enhanced Electrocatalytic N₂ Reduction to NH₃

Perovskite Oxides for Cathodic Electrocatalysis of Energy‐Related Gases: From O₂ to CO₂ and N₂

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Porous LaFeO3 nanofiber with oxygen vacancies as an efficient electrocatalyst for N2 conversion to NH3 under ambient conditions

Cited by 98 publications

References 65 publications

A General Strategy to Boost Electrocatalytic Nitrogen Reduction on Perovskite Oxides via the Oxygen Vacancies Derived from A‐Site Deficiency

A General Strategy to Boost Electrocatalytic Nitrogen Reduction on Perovskite Oxides via the Oxygen Vacancies Derived from A‐Site Deficiency

WO3 Rich in Oxygen Vacancies Through Ion‐Exchange Reaction for Enhanced Electrocatalytic N2 Reduction to NH3

Perovskite Oxides for Cathodic Electrocatalysis of Energy‐Related Gases: From O2 to CO2 and N2

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Product

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About

WO₃ Rich in Oxygen Vacancies Through Ion‐Exchange Reaction for Enhanced Electrocatalytic N₂ Reduction to NH₃

Perovskite Oxides for Cathodic Electrocatalysis of Energy‐Related Gases: From O₂ to CO₂ and N₂