TY - JOUR

T1 - Thermal prehistory, structure and high-temperature thermodynamic properties of Y2O3-CeO2 and Y2O3-ZrO2-CeO2 solid solutions

AU - Kurapova, Olga Yu

AU - Shugurov, Sergey M.

AU - Vasil'eva, Evgenia A.

AU - Savelev, Daniil A.

AU - Konakov, Vladimir G.

AU - Lopatin, Sergey I.

N1 - Funding Information: This research work was supported by the President's grant for young scientists (research project 75-15-2019-210). The DSC and ESCA data were obtained at the Research park of St. Petersburg State University by the Center for Thermogravimetric and Calorimetric Research and the Center for Studies in Surface Science, respectively. The language editing service was supported by Saint Petersburg Committee on Science and High School grant for young scientists. Publisher Copyright: © 2020 Elsevier Ltd and Techna Group S.r.l. Copyright: Copyright 2020 Elsevier B.V., All rights reserved.

PY - 2020/12/30

Y1 - 2020/12/30

N2 - Ceria-based solid solutions are important materials for high- and medium-temperature electrochemical applications. However, the stabilities of both binary and ternary ceria-based solid solutions are insufficient at elevated temperatures, which limits their application as solid electrolytes or SOFC cathodes. Data on the high-temperature stability of ceria-based ceramics are unavailable in the literature. In the present study, we report a thermodynamic stability investigation of Y2O3-CeO2 and Y2O3-ZrO2-CeO2 solid solutions. The thermal prehistories of binary and ternary systems were investigated using STA, XRD, and ESCA techniques. The vaporization processes were investigated in the temperature range of 1577–2227°С via the Knudsen effusion mass spectrometry technique. Using data on the component activity in solid-phase thermodynamic properties of Y2O3-CeO2 solid solutions, which is represented as the Gibbs energy, the excess Gibbs energy was calculated as a function of the ceria mol. %. It was shown that the reduction of Ce4+ to Ce3+ in Y2O3-CeO2 and Y2O3-ZrO2-CeO2 solid solutions corresponds to less-negative Gibbs energy compared to ZrO2-CeO2 solid solutions.

AB - Ceria-based solid solutions are important materials for high- and medium-temperature electrochemical applications. However, the stabilities of both binary and ternary ceria-based solid solutions are insufficient at elevated temperatures, which limits their application as solid electrolytes or SOFC cathodes. Data on the high-temperature stability of ceria-based ceramics are unavailable in the literature. In the present study, we report a thermodynamic stability investigation of Y2O3-CeO2 and Y2O3-ZrO2-CeO2 solid solutions. The thermal prehistories of binary and ternary systems were investigated using STA, XRD, and ESCA techniques. The vaporization processes were investigated in the temperature range of 1577–2227°С via the Knudsen effusion mass spectrometry technique. Using data on the component activity in solid-phase thermodynamic properties of Y2O3-CeO2 solid solutions, which is represented as the Gibbs energy, the excess Gibbs energy was calculated as a function of the ceria mol. %. It was shown that the reduction of Ce4+ to Ce3+ in Y2O3-CeO2 and Y2O3-ZrO2-CeO2 solid solutions corresponds to less-negative Gibbs energy compared to ZrO2-CeO2 solid solutions.

KW - Ceria

KW - Knudsen effusion mass spectrometry

KW - SOFC

KW - Thermodynamic properties

KW - Yttria

KW - Zirconia

UR - http://www.scopus.com/inward/record.url?scp=85098600900&partnerID=8YFLogxK

UR - https://www.mendeley.com/catalogue/b03516db-f299-32d3-800f-0408eaf39b75/

U2 - 10.1016/j.ceramint.2020.12.230

DO - 10.1016/j.ceramint.2020.12.230

M3 - Article

AN - SCOPUS:85098600900

JO - Ceramics International

JF - Ceramics International

SN - 0272-8842

ER -