Fundamental Understanding and Applications of Protonic Y‐ and Yb‐Coped Ba(Ce,Zr)O₃ Perovskites: State‐of‐the‐Art and Perspectives

Abstract

Proton‐conducting oxide materials are interesting objects from both fundamental and applied viewpoints due to the origination of protonic defects in a crystal structure as a result of their interaction with hydrogen‐containing atmospheres at elevated temperatures. The high mobility of such defects at temperatures between 400 and 700 °C leads to superior ionic conductivity. As a result, some perovskite‐type proton‐conducting oxides have been proposed as electrolytes for solid oxide fuel and electrolysis cells. Barium cerate (BaCeO3), barium zirconate (BaZrO3), and barium cerate‐zirconates (BaCeO3–BaZrO3) have been widely studied in terms of the parent phases of proton‐conducting electrolytes. Among them, Y and Yb co‐doped Ba(Ce,Zr)O3 can be identified as one of the most promising systems so far. This review discloses key functional properties of such phases and explains the increased attention of researchers to this system.

Effect of NiO Addition on the Sintering and Electrochemical Properties of BaCe0.55Zr0.35Y0.1O3-δ Proton-Conducting Ceramic Electrolyte

“…BaCeO 3 /BaZrO 3 oxides and hexagonal perovskites have been widely studied as proton conductors [ 10 , 11 , 12 , 13 ]. BaCeO 3 -based oxides exhibit excellent proton conductivity at intermediate temperatures, with a low proton conduction activation energy (0.4–0.6 eV) compared with the activation energy for oxygen ion transport [ 14 , 15 ]. However, at the actual PCFC operating temperature, BaCeO 3 -based oxides are unstable in the presence of acidic gases such as CO 2 and/or steam [ 15 ].…”

“…BaCeO 3 -based oxides exhibit excellent proton conductivity at intermediate temperatures, with a low proton conduction activation energy (0.4–0.6 eV) compared with the activation energy for oxygen ion transport [ 14 , 15 ]. However, at the actual PCFC operating temperature, BaCeO 3 -based oxides are unstable in the presence of acidic gases such as CO 2 and/or steam [ 15 ]. In contrast, BaZrO 3 -based oxides demonstrate high chemical stability but low ionic conductivity [ 16 , 17 ].…”

A highly stable Pr2NiO4+δ oxygen electrode in electrolyte supported protonic ceramic electrolysis cells (PCECs) for hydrogen production with high faradaic efficiency

“…Nowadays, the proposed composition of BCZYYb7111 is one of the most studied electrolyte materials and promising results were obtained in PCFC and PCEC applications. [7][8][9][10][11][12][13] However, in recent studies severe concerns about the chemical stability of BCZYYb7111 in H 2 O or CO 2 rich atmospheres were raised. [14][15][16][17] Higher zirconium contents (430-40 mol% of zirconium) were proposed to be necessary to achieve sufficient stability under these conditions.…”

Synthesis and electrical properties of doped layered perovskites based on BaMInO4 (M = Y, Gd)

“…The design and production of such devices is part of the strategy of sustainable environmental development [9][10][11][12][13][14][15][16]. The most studied proton conductors are barium cerates-zirconates [17][18][19][20][21][22][23][24]. The barium zirconate crystallises in the classic perovskite ABO3 structure.…”