dc.date.accessioned | 2021-04-19T19:56:15Z | |
dc.date.available | 2021-04-19T19:56:15Z | |
dc.date.created | 2021-02-01T17:15:33Z | |
dc.date.issued | 2020 | |
dc.identifier.citation | Kalland, Liv-Elisif Queseth Løken, Andreas Bjørheim, Tor Svendsen Haugsrud, Reidar Norby, Truls Eivind . Structure, hydration, and proton conductivity in 50% La and Nd doped CeO2 – La2Ce2O7 and Nd2Ce2O7 – and their solid solutions. Solid State Ionics. 2020, 354, 115401 | |
dc.identifier.uri | http://hdl.handle.net/10852/85351 | |
dc.description.abstract | We have measured water uptake and hydration enthalpy in 50% La and Nd doped CeO2, also to be taken as compositions in the series La2−xNdxCe2O7 (x = 0.0, 0.5, 1.0 and 2.0) using combined thermogravimetry (TG) and differential scanning calorimetry (DSC), TG-DSC. The TG-DSC data unambiguously yield standard molar hydration enthalpies of ~−74 kJ/mol independent of water uptake. The interpretation of the TG results, however, does not fit a classical model of hydration of all oxygen vacancies. Instead, the hydration appears to be limited to a small fraction of the free vacancies. Hydration further decreases as the Nd content (x) and long-range order increases and regions of disorder decrease. We propose a new model explaining why hydration occurs only in a small fraction of the nominally free vacancies: The higher basicity of La/Nd compared to Ce promotes protonation at oxide ion sites with high coordination to La/Nd, and the observed water uptake and modelling suggests that mainly oxide ions fully coordinated to 4 La/Nd neighbours become protonated. The statistical variation of coordination around oxygen sites in a disordered fluorite oxide creates a limited number of such oxide ions sites which results in limited hydration. The model matches well the experimental results and DFT calculations of proton trapping at the fully La-coordinated sites for 50% La-doped CeO2, and also rationalizes conductivity data. | |
dc.language | EN | |
dc.rights | Attribution 4.0 International | |
dc.rights.uri | https://creativecommons.org/licenses/by/4.0/ | |
dc.title | Structure, hydration, and proton conductivity in 50% La and Nd doped CeO2 – La2Ce2O7 and Nd2Ce2O7 – and their solid solutions | |
dc.type | Journal article | |
dc.creator.author | Kalland, Liv-Elisif Queseth | |
dc.creator.author | Løken, Andreas | |
dc.creator.author | Bjørheim, Tor Svendsen | |
dc.creator.author | Haugsrud, Reidar | |
dc.creator.author | Norby, Truls Eivind | |
cristin.unitcode | 185,15,12,0 | |
cristin.unitname | Kjemisk institutt | |
cristin.ispublished | true | |
cristin.fulltext | original | |
cristin.qualitycode | 1 | |
dc.identifier.cristin | 1885416 | |
dc.identifier.bibliographiccitation | info:ofi/fmt:kev:mtx:ctx&ctx_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:journal&rft.jtitle=Solid State Ionics&rft.volume=354&rft.spage=115401&rft.date=2020 | |
dc.identifier.jtitle | Solid State Ionics | |
dc.identifier.volume | 354 | |
dc.identifier.doi | https://doi.org/10.1016/j.ssi.2020.115401 | |
dc.identifier.urn | URN:NBN:no-88005 | |
dc.type.document | Tidsskriftartikkel | |
dc.type.peerreviewed | Peer reviewed | |
dc.source.issn | 0167-2738 | |
dc.identifier.fulltext | Fulltext https://www.duo.uio.no/bitstream/handle/10852/85351/1/1-s2.0-S0167273820304550-main.pdf | |
dc.type.version | PublishedVersion | |
cristin.articleid | 115401 | |