A combination of surface area analyzer and microcalorimetry was employed to investigate the in situ water uptake energetics and the mechanism of proton incorporation in yttrium-doped barium zirconate in the temperature range 200–400 °C. The BaZr1–xYxO3 solid solutions are made with variable yttrium content (x = 10, 20, and 30 mol %) by a controlled oxidant-peroxo synthesis method. The water uptake increases as the partial pressure of water increases; however, no saturation in the hydration isotherm is observed, implying further reaction at higher pH2O. The results suggest three distinct regions of hydration energies as a function of water content. The first water uptake enthalpy values showed high exothermicity, −140, −158, and −157 kJ mol–1 for BaZr1–xYxO3 (x = 10, 20, and 30 mol %), respectively, at 400 °C, and the strong exothermic contribution supports the dissociative incorporation of water. The stepwise in situ hydration energetics is essential to understand the mechanisms of water incorporation and the role of H2O uptake in transport properties.
Authors
- Mayra Goncalves,
- dr hab. inż. Aleksandra Mielewczyk-Gryń link open in new tab ,
- Dr Pardha Saradhi Maram,
- Łukasz Kryścio link open in new tab ,
- prof. dr hab. inż. Maria Gazda link open in new tab ,
- Alexandra Navrotsky
Additional information
- DOI
- Digital Object Identifier link open in new tab 10.1021/acs.jpcc.0c01049
- Category
- Publikacja w czasopiśmie
- Type
- artykuły w czasopismach
- Language
- angielski
- Publication year
- 2020
