Structural and Transport Properties of Nd Tungstates and Their Composites with Ni0.5Cu0.5O Obtained by Mechanical Activation Full article
| Journal |
Dalton Transactions
ISSN: 1477-9226 , E-ISSN: 1477-9234 |
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| Output data | Year: 2022, Volume: 51, Number: 19, Pages: 7705-7714 Pages count : 10 DOI: 10.1039/d2dt00498d | ||
| Tags | Chemical activation; Copper oxides; Diffusion; Fluorspar; Grain boundaries; Hydrogen; Lanthanum compounds; Membranes; Molybdenum compounds; Neodymium compounds; Nickel compounds; Tungsten compounds | ||
| Authors |
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| Affiliations |
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Funding (1)
| 1 | Ministry of Science and Higher Education of the Russian Federation | 0239-2021-0011 |
Abstract:
Nd tungstates and molybdates are promising materials for hydrogen separation membranes due to their high protonic conductivity. This work aims at elucidating the structural, textural and oxygen transport features of Nd5.5WO11.25−δ, Nd5.5W0.5Mo0.5O11.25−δ and (Nd5/6La1/6)5.5WO11.25−δ and their composites with Ni0.5Cu0.5O synthesized by mechanical activation. The oxide materials obtained were distorted double fluorites but their composites with Ni0.5Cu0.5O possess a complex phase composition. Extended defects such as grain boundaries, stacking faults and surface steps/terraces were observed in TEM images, which allow fast diffusion transport along grain boundaries
(D* ∼ 10−6 cm2 s−1 at 700 °C) and slower diffusion within grains’ bulk (D* ∼ 10−11, 10−12 and 10−13 cm2 s−1 at 700 °C for the rather fast, “middle” and slow channels of bulk diffusion) (2D diffusion). The model gives the best description of experimental data obtained by the isotope exchange of oxygen with C18O2 in a flow reactor. For composites with
Ni0.5Cu0.5O, a significant decrease in oxygen diffusivity was shown. The reduction and subsequent reoxidation
of composites resulted in an increase in oxygen mobility probably due to the partial unblocking of oxygen diffusion corresponding to the Ln tungstates/molybdates. Fine oxygen transport features allow us to increase the hydrogen yield of hydrogen separation membranes due to the proton transport mechanisms involving oxide anions and the water splitting reaction. Hence, the features of Nd tungstates and their composites with nickel(II)–copper(II) oxide studied demonstrated their high potential for use in catalytic reactors based on hydrogen separation membranes.
Cite:
Eremeev N.F.
, Bespalko Y.N.
, Sadovskaya E.M.
, Skriabin P.I.
, Krieger T.A.
, Ishchenko A.V.
, Sadykov V.A.
Structural and Transport Properties of Nd Tungstates and Their Composites with Ni0.5Cu0.5O Obtained by Mechanical Activation
Dalton Transactions. 2022. V.51. N19. P.7705-7714. DOI: 10.1039/d2dt00498d WOS Scopus РИНЦ AN PMID OpenAlex
Structural and Transport Properties of Nd Tungstates and Their Composites with Ni0.5Cu0.5O Obtained by Mechanical Activation
Dalton Transactions. 2022. V.51. N19. P.7705-7714. DOI: 10.1039/d2dt00498d WOS Scopus РИНЦ AN PMID OpenAlex
Dates:
| Submitted: | Feb 16, 2022 |
| Accepted: | Apr 21, 2022 |
| Published online: | Apr 21, 2022 |
| Published print: | May 21, 2022 |
Identifiers:
| Web of science: | WOS:000791986700001 |
| Scopus: | 2-s2.0-85130633863 |
| Elibrary: | 48591402 |
| Chemical Abstracts: | 2022:1213302 |
| PMID: | 35521896 |
| OpenAlex: | W4226034872 |