Phase stabilisation, chemical behaviour and protonic conductivity of vanadium doped Barium Indate for ITSOFC application

Tyagi, Deepak; Shirsat, A.N.; Saha, Bikash; Varma, Salil

doi:10.1016/j.jallcom.2021.160298

Cited by 3 publications

(5 citation statements)

References 33 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Besides the difference in activation energy for long-range proton diffusion, we also note a clear difference in regard to the value of the macroscopic proton conductivity between hydrated barium indate and proton-conducting perovskites. Specifically, we note that the proton conductivities obtained from impedance spectroscopy measurements of Ba 2 In 2 O 5 (H 2 O) x are 1–3 orders of magnitude lower than those in the best proton-conducting perovskites, such as Y-doped BaZrO 3 . − However, for the proton diffusion coefficients as determined by QENS, the values for different relevant proton conductors are similar. For instance, the related material BaZr 1− x In x O 3− x /2 exhibits proton diffusion coefficients of 1–3 Å 2 /ns, which are within the same range as observed here for BIO92 (0.45–2.4 Å 2 /ns).…”

Section: Discussionmentioning

confidence: 79%

“…A strategy to preserve an oxygen-vacancy-free structure while reducing the number of protons could be to partially substitute indium atoms with tetravalent or pentavalent cations. For instance, dehydrated vanadium-substituted barium indate still displays the brownmillerite structure at moderate substitution content (≤20%) and shows under a moist Ar atmosphere about an order of magnitude increase in total conductivity compared to pristine barium indate . Similarly, moderate substitution by titanium (≤20%) and additional elements, or high substitution by vanadium (≤40%), has been shown to stabilize the high-temperature tetragonal structure of barium indate and improve protonic conductivities.…”

Section: Discussionmentioning

confidence: 99%

See 1 more Smart Citation

Proton Diffusion Mechanism in Hydrated Barium Indate Oxides

et al. 2023

View full text Add to dashboard Cite

We report on quasielastic neutron scattering (QENS) and ab initio molecular dynamics (AIMD) simulations of the mechanism of proton diffusion in the partially and fully hydrated barium indate oxide proton conductors Ba 2 In 2 O 5 (H 2 O) x (x = 0.30 and 0.92). Structurally, these materials are featured by an intergrowth of cubic and "pseudo-cubic" layers of InO 6 octahedra, wherein two distinct proton sites, H(1) and H(2), are present. We show that the main localized dynamics of these protons can be described as rotational diffusion of O−H(1) species and H(2) proton transfers between neighboring oxygen atoms. The mean residence times of both processes are in the order of picoseconds in the two studied materials. For the fully hydrated material, Ba 2 In 2 O 5 (H 2 O) 0.92 , we also reveal the presence of a third proton site, H(3), which becomes occupied upon increasing the temperature and serves as a saddle state for the interexchange between H(1) and H(2) protons. Crucially, the occupation of the H(3) site enables long-range diffusion of protons, which is highly anisotropic in nature and occurs through a two-dimensional pathway. For the partially hydrated material, Ba 2 In 2 O 5 (H 2 O) 0.30 , the occupation of the H(3) site and subsequent long-range diffusion are not observed, which is rationalized by hindered dynamics of H(2) protons in the vicinity of oxygen vacancies. A comparison to state-of-the-art proton-conducting oxides, such as barium zirconate-based materials, suggests that the generally lower proton conductivity in Ba 2 In 2 O 5 (H 2 O) x is due to a large occupation of the H(1) and H(2) sites, which, in turn, means that there are few sites available for proton diffusion. This insight suggests that the chemical substitution of indium by cations with higher oxidation states offers a novel route toward higher proton conductivity because it reduces the proton site occupancy while preserving an oxygen-vacancy-free structure.

show abstract

Section: Discussionmentioning

confidence: 79%

Section: Discussionmentioning

confidence: 99%

Proton Diffusion Mechanism in Hydrated Barium Indate Oxides

et al. 2023

View full text Add to dashboard Cite

show abstract

“…The phase is characterized by monoclinic symmetry (sp. group P2/c) with the unit cell parameters a = 7.942(1) Å, b = 5.868(5) Å, c = 18.201(6) Å,  = 91.52 (9).…”

Section: Resultsmentioning

confidence: 99%

“…The most oxygen-incomplete type in perovskite-like family is the brownmillerite structure with the general formula A2B2O5, where the B-cations occupy two polyhedral positions [BO6] and [BO4] with alternating octahedral and tetrahedral layers in the structure, and one oxygen position per formula unit is vacant A2B2O5(VO)1. The Ba2In2O5 barium indate with the brownmillerite structure is well-studied and described as oxygen-ion and proton conductor; solid solutions based on it remain in the attention focus of some researchers [5][6][7][8][9]. But it is interesting to find other complex oxides with structural oxygen vacancies, potentially exhibiting the proton conductivity.…”

Section: Introductionmentioning

confidence: 99%

Oxygen-ion and proton conductivity in the Ba₃InGa₂O_7.5 complex oxide with incomplete oxygen sublattice

Kochetova,

Cherepanova,

Pikalova

et al. 2024

Chim.Tech.Acta

View full text Add to dashboard Cite

The Ba3InGa2O7.5 complex oxide, possessing the perovskite-related structure with structural oxygen vacancies, was first synthesized by the solid state method. The phase was found to be characterized by monoclinic symmetry (sp. gr. P2/c) with the following unit cell parameters: a = 7.942(1) Å, b = 5.868(5) Å, c = 18.201(6) Å, b = 91.52(9). Comprehensive investigations of electrical properties were carried out; ceramic material based on the complex oxide was shown to be a predominantly ionic conductor in the temperature range 450–900 oC. The conductivity is due to oxygen-ion transfer in dry conditions and oxygen-ion and proton transfer in wet atmosphere. The proton conductivity value is 4.5·10–5 S/cm, and the proton transport number is ~50% at 700 oC in wet air; at lower temperatures, proton transport becomes dominant. Prolonged treatment of the sample in water vapors below 450 oC leads to hydrolysis decomposition.

show abstract

“…The brownmillerite-type material Ba 2 In 2 O 5 has already demonstrated striking potential in various applications, ranging from the photocatalytic CO 2 conversion in the presence of H 2 [1][2][3] via oxygen transport membranes [4] to proton conductors [5][6][7][8][9]. The latter is related to the well-known reversible uptake of H 2 O by Ba 2 In 2 O 5 .…”

Section: Introductionmentioning

confidence: 99%

Effects of Cr Doping and Water Content on the Crystal Structure Transitions of Ba2In2O5

et al. 2021

View full text Add to dashboard Cite

Temperature-dependent crystal structure alterations in the brownmillerite-type material Ba2In2O5 play a fundamental role in its applications: (i) photocatalytic CO2 conversion; (ii) oxygen transport membranes; and (iii) proton conduction. This is connected to a reversible uptake of up an equimolar amount of water. In this study, in situ X-ray and neutron diffraction were combined with Raman spectroscopy and solid-state nuclear magnetic resonance experiments to unravel the effects of Cr doping and water content on the crystal structure transitions of Ba2In2O5(H2O)x over a wide temperature range (10 K ≤ T ≤ 1573 K, x < 1). A mixture of isolated and correlated protons was identified, leading to a highly dynamic situation for the protons. Hence, localisation of the protons by diffraction techniques was not possible. Cr doping led to an overall higher degree of disorder and stabilisation of the tetragonal polymorph, even at 10 K. In contrast, a further disordering at high temperatures, leading to a cubic polymorph, was found at 1123 K. Cr doping in Ba2In2O5 resulted in severe structural changes and provides a powerful way to adjust its physical properties to the respective application.

show abstract

Phase stabilisation, chemical behaviour and protonic conductivity of vanadium doped Barium Indate for ITSOFC application

Cited by 3 publications

References 33 publications

Proton Diffusion Mechanism in Hydrated Barium Indate Oxides

Proton Diffusion Mechanism in Hydrated Barium Indate Oxides

Oxygen-ion and proton conductivity in the Ba₃InGa₂O_7.5 complex oxide with incomplete oxygen sublattice

Effects of Cr Doping and Water Content on the Crystal Structure Transitions of Ba2In2O5

Contact Info

Product

Resources

About

Phase stabilisation, chemical behaviour and protonic conductivity of vanadium doped Barium Indate for ITSOFC application

Cited by 3 publications

References 33 publications

Proton Diffusion Mechanism in Hydrated Barium Indate Oxides

Proton Diffusion Mechanism in Hydrated Barium Indate Oxides

Oxygen-ion and proton conductivity in the Ba3InGa2O7.5 complex oxide with incomplete oxygen sublattice

Effects of Cr Doping and Water Content on the Crystal Structure Transitions of Ba2In2O5

Contact Info

Product

Resources

About

Oxygen-ion and proton conductivity in the Ba₃InGa₂O_7.5 complex oxide with incomplete oxygen sublattice