Electrical conductivity of lanthanum oxide based composites containing carbon nanofibers

Володин, А. А.; Фурсиков, П. В.; Бельмесов, А. А.; Shul’ga, Yu. M.; Khodos, I. I.; Abdusalyamova, M. N.; Тарасов, Б. П.

doi:10.1134/s0020168514070164

Cited by 6 publications

(6 citation statements)

References 24 publications

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“…The ORR volcano plots show a near top position of the LaNiO 3 activity and this material exhibits metal‐like conductivities at room temperature . Besides, the electronic configuration with 1 e‐filled e g orbital of this perovskites due to presence of low‐spin t 2g 6 e g 1 from Ni 3+ (d 7 ) has been recently evidenced to be very promising in ORR . In particular, LaNiO 3 is stable over a wide potential range for the ORR in alkaline solution .…”

Section: Introductionmentioning

confidence: 88%

Porous Hollow‐Structured LaNiO₃ Stabilized N,S‐Codoped Graphene as an Active Electrocatalyst for Oxygen Reduction Reaction

Lee

Nguyen

Balamurugan

et al. 2017

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A nanohybrid based on porous and hollow interior structured LaNiO stabilized nitrogen and sulfur codoped graphene (LaNiO /N,S-Gr) is successfully synthesized for the first time. Such a nanohybrid as an electrocatalyst shows high catalytic activity for oxygen reduction reaction (ORR) in O -saturated 0.1 m KOH media. In addition, it demonstrates a comparable catalytic activity, longer working stability, and much better alcohol tolerance compared with commercial Pt/C behavior in same experiment condition. The obtained results are attributed to synergistic effects from the enhanced electrocatalytic active sites on the rich pore channels of porous hollow-structured LaNiO spheres and heteroatom doped efficiency on graphene structure. In addition, N,S-Gr can meritoriously stabilize monodispersion of the LaNiO spheres, and act as medium bridging for high electrical conductivity, thereby providing large active surface area for O adsorption, accelerating reduction reaction, and improving electrochemical stability. Such a hybrid opens an interesting class of highly efficient non-Pt catalysts for ORR in alkaline media.

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Section: Introductionmentioning

confidence: 88%

Porous Hollow‐Structured LaNiO₃ Stabilized N,S‐Codoped Graphene as an Active Electrocatalyst for Oxygen Reduction Reaction

Lee

Nguyen

Balamurugan

et al. 2017

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“…5b,9b,15 Furthermore, the Ni 3+ (d 7 ) ion in LNO has a stable low-spin (LS) t 2g 6 e g 1 configuration. 16 In addition to recent evidence showing that perovskites with an e g -filling of 1 e − are promising oxygen electrocatalysts, 14b the robust LS e g 1 occupation allows us to focus solely on symmetry changes within the e g orbitals. Finally, LNO in alkaline solution is stable over a wide range of potentials involving the ORR and OER.…”

mentioning

confidence: 99%

“…Moreover, LNO in the bulk form is already more catalytic than Pt toward the OER, though it has not yet shown higher activity than NiFeO x and α-Mn 2 O 3 . , Similar to the other oxides, its bifunctionality is limited by a lower activity toward the ORR . Since the rate-determining step (RDS) in both reactions is linked to excessive Ni–O chemisorption to hydroxyl groups, tuning these energies through strain could enhance both ORR and OER. ,, Furthermore, the Ni 3+ (d 7 ) ion in LNO has a stable low-spin (LS) t 2g 6 e g 1 configuration . In addition to recent evidence showing that perovskites with an e g -filling of 1 e – are promising oxygen electrocatalysts, the robust LS e g 1 occupation allows us to focus solely on symmetry changes within the e g orbitals.…”

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confidence: 99%

Enhanced Bifunctional Oxygen Catalysis in Strained LaNiO₃ Perovskites

Petrie¹,

Cooper²,

et al. 2016

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ABSTRACT:Strain is known to greatly influence low temperature oxygen electrocatalysis on noble metal films, leading to significant enhancements in bifunctional activity essential for fuel cells and metal-air batteries. However, its catalytic impact on transition metal oxide (TMO) thin films, such as perovskites, is not widely understood. Here, we epitaxially strain the conducting perovskite LaNiO 3 to systematically determine its influence on both the oxygen reduction (ORR) and oxygen evolution reaction (OER). Uniquely, we found that compressive strain could significantly enhance both reactions, yielding a bifunctional catalyst that surpasses the performance of noble metals such as Pt. We attribute the improved bifunctionality to straininduced splitting of the e g orbitals, which can customize orbital asymmetry at the surface. Analogous to straininduced shifts in the d-band center of noble metals relative to Fermi level, such splitting can dramatically affect catalytic activity in this perovskite and other potentially more active oxides. Advancements in energy storage are essential for driving the development of more sophisticated mobile technologies as well as continuing the trend towards a greener economy. At the forefront of this push are high energy density devices, such as regenerative fuel cells and metal-air batteries. 1 In these and related electrochemical systems, both the oxygen reduction and oxygen evolution reactions (ORR and OER, respectively) are crucial towards successful operation. 2 Traditionally, conductive catalysts incorporating noble metals (e.g., Pt and IrO 2 ) have been used to facilitate these reactions near room temperature. 3 To alleviate costs and poor stabilities during OER in alkaline solutions, significant efforts have focused on transition metal oxides (TMOs) with multivalent Ni, Fe, Co, and Mn, such as NiFeO x .4 Similar to alloying in noble metals, the majority of research into increasing oxygen activities of TMOs involves cationic doping, which often promotes either the ORR or OER but not bifunctionality. 5Here, we explore how another factor, i.e. strain, can influence bifunctionality in TMOs. Contemporary work on high-temperature (>500 C) oxide catalysis in an aprotic environment (e.g. ORR: O 2 + 4e -→ 2O 2-) has emphasized the importance of tensile strain for activating defects to improve catalytic reactions. 6 In an alkaline environment (e. . Among TMOs, the ABO 3 perovskites, in which A is traditionally from Groups I-III and B is a transition metal ion with six-fold octahedral coordination, also have electronic structures that are sensitive to strain. Due to strong hybridization between the O 2p and the transition metal d z 2 and d x 2 -y 2 lobes in the BO 6 octahedra, the σ* states near E F consist of e g orbitals. 10,10b Similar to the Jahn-Teller distortion, strain is known to lift the degeneracy in these symmetry-localized d z 2 and d x 2 -y 2 orbitals, yielding changes in the orbital occupancy, or polarization.7a, 11 By using strain to control the degree of this ...

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“…In our studies [14,15], it was noted that the addition of 3 wt.% of carbon nanotubes and nanofibers to titanium or lanthanum oxides leads to a significant increase in conductivity. Composites based on nickel hydroxide were also formed: G/Ni(OH) 2 , CNT/Ni(OH) 2 , CNF/Ni(OH) 2 , and GLM/Ni(OH) 2 containing 3 wt.% of the carbon component.…”

Section: Composite Materialsmentioning

confidence: 68%

Advanced Materials for Nickel—Metal Hydride Chemical Power Sources

Володин¹,

Тарасов²,

Blinov³

2019

dteees

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A general survey on Ni-MH power sources is given, their advantages and disadvantages are shown, and the reported experimental data for improving their performance are summarized. The prospect of using carbon nanostructures to improve the performance of electrodes is considered and the effectiveness of their use is shown. The resulting materials can be used to produce electrodes for Ni-MH batteries and metal hydride fuel cells.

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Electrical conductivity of lanthanum oxide based composites containing carbon nanofibers

Cited by 6 publications

References 24 publications

Porous Hollow‐Structured LaNiO₃ Stabilized N,S‐Codoped Graphene as an Active Electrocatalyst for Oxygen Reduction Reaction

Porous Hollow‐Structured LaNiO₃ Stabilized N,S‐Codoped Graphene as an Active Electrocatalyst for Oxygen Reduction Reaction

Enhanced Bifunctional Oxygen Catalysis in Strained LaNiO₃ Perovskites

Advanced Materials for Nickel—Metal Hydride Chemical Power Sources

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Electrical conductivity of lanthanum oxide based composites containing carbon nanofibers

Cited by 6 publications

References 24 publications

Porous Hollow‐Structured LaNiO3 Stabilized N,S‐Codoped Graphene as an Active Electrocatalyst for Oxygen Reduction Reaction

Porous Hollow‐Structured LaNiO3 Stabilized N,S‐Codoped Graphene as an Active Electrocatalyst for Oxygen Reduction Reaction

Enhanced Bifunctional Oxygen Catalysis in Strained LaNiO3 Perovskites

Advanced Materials for Nickel—Metal Hydride Chemical Power Sources

Contact Info

Product

Resources

About

Porous Hollow‐Structured LaNiO₃ Stabilized N,S‐Codoped Graphene as an Active Electrocatalyst for Oxygen Reduction Reaction

Porous Hollow‐Structured LaNiO₃ Stabilized N,S‐Codoped Graphene as an Active Electrocatalyst for Oxygen Reduction Reaction

Enhanced Bifunctional Oxygen Catalysis in Strained LaNiO₃ Perovskites