Processing of yttrium-doped barium zirconate for high proton conductivity

Babilo, Peter; Uda, Tetsuya; Haile, Sossina M.

doi:10.1557/jmr.2007.0163

Cited by 405 publications

(348 citation statements)

References 28 publications

Supporting

Mentioning

304

Contrasting

Unclassified

Order By: Relevance

“…8). The shape and size of the semicircle did not depend on electrode polarization, which indicates that the processes characterized by this semicircle do not take place in Pt electrode and in three phase boundary of Pt electrode, gas phase and electrolyte and as accepted in literature 21 are characteristic for processes at grain boundary interfaces and bulk phase (Fig. 8).…”

Section: Preparation Of Protective Bazrsupporting

confidence: 60%

See 1 more Smart Citation

Comparative Study of BaY_0.1Zr_0.9O_3-δProtective Layers Deposited to BaY_0.1Ce_0.9O_3-δMembrane Using Ultrasonic Spray Pyrolysis and Magnetron Sputtering Methods

Maide

Korjus

Vestli

et al. 2016

J. Electrochem. Soc.

View full text Add to dashboard Cite

To combine chemical stability of BaY 0.1 Zr 0.9 O 3-δ (BZY) and good proton conductive properties of BaY 0.1 Ce 0.9 O 3-δ (BCY) bilayer membranes were prepared. Supportive BCY membranes were prepared applying dry pressing of nanopowder, which was synthesized with ultrasonic spray pyrolysis method. Thin protective BZY coatings were prepared using ultrasonic spray pyrolysis and magnetron sputtering methods. Ultarsonic spray pyrolyzed BZY layers were 0.5-1.1 μm thick, phase pure and with some closed porosity. Protective BZY layers synthesized with reactive magnetron sputtering method were approximately 0.7 μm thick, highly dense and with good phase purity. Activation energy for BCY membrane was 0.35 eV. BZY protective layer sintered at relatively low temperatures (600 to 1150 • C) had minor influence on total activation energy. Sintering at 1350 • C led to a decrease of activation energy of proton transport process at grain boundary region, an increase of activation energy of proton transport in bulk and a slight increase of total activation energy. Sintering at 1350 • C and higher temperatures led to interdiffusion of Zr and Ce cations between BZY and BCY phases and changes in chemical as well as electrochemical properties. Prepared membranes with BZY layer were exposed to CO 2 at 700 • C and were observed to be chemically stable if sintering of BZY were carried out at 1150 • C and lower temperatures. High temperature proton conductive (HTPC) oxide membranes have a variety of applications, such as hydrogen sensors for detecting hydrogen in gases and in melted metals, 1,2 detection systems of hydrocarbons in natural gas, devices for hydrogen extraction and precise pumping, reactors for electrochemical hydrogenation, dehydrogenation and production of ammonia 1-3 etc. Furthermore, these membranes can be used in fuel cells as well as in electrolyzers having some advantages in comparison with oxide ion conductive membranes: a) hydrogen and water are not mixed in fuel cell nor in electrolysis regime and b) higher conductivity and lower activation energy at intermediate temperatures compared with conventional oxide ion conductors.A variety of different chemical compositions has been tested as potential HTPC oxide membrane materials. For example, Ba-, Sr-, Gd-, La-, and Ca -cerates, zirconates, stannates, niobates and titanates, which are doped with Y, In, Gd, Sm, Sc, Ga . [4][5][6][7] In some studies binary oxides with fluoritelike structure and ternary oxides with pyrochloric structure have been studied as well.8 Acceptor doped barium cerate shows the highest protonic conductivities but poor chemical stability. BaCeO 3 and SrCeO 3 are thermodynamically only weakly stabilized and the formation of carbonates takes place in the presence of CO 2 . The stability with respect to the formation of carbonates and hydroxides increases in the order of materials: cerate < zirconate < titanate, i.e., opposite to the direction of the increase of stability of protonic defects and as the B site cation electronegativity increases. Some ...

show abstract

Section: Preparation Of Protective Bazrsupporting

confidence: 60%

“…Grain boundary resistance R gb was obtained by subtraction of R bulk from R tot value. The characteristic frequencies of high frequency semicircles were typical for grain boundary processes in HTPC 21 and varied from 10 kHz to 250 kHz in studied temperature range (550…”

Section: Preparation Of Protective Bazrmentioning

confidence: 99%

Comparative Study of BaY_0.1Zr_0.9O_3-δProtective Layers Deposited to BaY_0.1Ce_0.9O_3-δMembrane Using Ultrasonic Spray Pyrolysis and Magnetron Sputtering Methods

Maide

Korjus

Vestli

et al. 2016

J. Electrochem. Soc.

View full text Add to dashboard Cite

show abstract

“…The electrical conductivity of the BZY_ZnO electrolyte was two to five times higher than that observed for the BZY electrolyte under the same conditions, which is due to its higher relative density. This result is in good agreement with data reported by Haile et al 17,20 In contrast, the BZY_ZnO_H 3 PO 4 electrolyte showed the lowest electrical conductivity, especially at temperatures above 300…”

Section: Resultssupporting

confidence: 93%

A Sensitive and Self-Regenerable Particulate Matter Sensor with a H₃PO₄-Modified BaZr_0.8Y_0.2O_3-δElectrolyte and an IrO₂-Catalyzed Sensing Electrode

Oogushi

Nakashima

et al. 2016

J. Electrochem. Soc.

View full text Add to dashboard Cite

There have been many attempts to develop solid-state sensor devices for detecting particulate matter (PM) in diesel exhaust; however, in most of these, the accumulated PM must be burned intermittently to allow subsequent sensing cycles. Here, we report a selfregenerable PM sensor using a proton conductive solid electrolyte and an active working electrode for PM oxidation. The withstanding voltage capability of BaZr 0.8 Y 0.2 O 3-δ was greatly improved by the growth of a dense Zr 1-x Y x P 2 O 7 film on the electrolyte surface. The reaction of PM with active oxygen under anodic polarization was further enhanced by the addition of IrO 2 to the working electrode. As a result of these combined modifications, when the working electrode was anodically polarized, PM was oxidized to CO 2 according to a four-electron reaction (C + 2H 2 O → CO 2 + 4H + + 4e -) while remaining below the self-ignition temperature. This amperometric sensor successfully produced a current signal corresponding to the quantity of PM in a gas stream at an operating temperature of 300 • C. These results demonstrate that the sensor can carry out continuous monitoring of PM concentrations while self-regenerating.

show abstract

“…The most promising proton conducting electrolytes are BaCe1-xYxO3-x/2 (BCY) 4,[8][9][10][11] and BaZr1-xYxO3-x/2 (BZY), [12][13][14][15][16] which exhibit high proton conductivity at intermediate temperatures (~500 C) 17 . Despite the encouraging proton conductivity of these materials, there are several issues addressed related to their chemical stability, mechanical properties and difficulties in sintering of BZY.…”

Section: -7mentioning

confidence: 99%

Effect of CO₂ Exposure on the Chemical Stability and Mechanical Properties of BaZrO₃‐Ceramics

et al. 2016

View full text Add to dashboard Cite

The reactivity of BaZrO3 with CO2 has been addressed as one of the major challenges with BaZrO3-based electrolytes in proton ceramic fuel cells. Here, we present a study of the effect of CO2 exposure of BaZrO3-materials at elevated temperatures. Dense BaZr1-xYxO3-δ (x = 0, 0.05, 0.1, 0.2) and BaCe0.2Zr0.7Y0.1O2.95 ceramics were prepared by conventional sintering of powder prepared by spray pyrolysis. The Vickers indentation method was used to determine the hardness and estimate the fracture toughness of pristine materials as well as the corresponding materials exposed to CO2. Formation of BaCO3 on the surface of exposed ceramics was confirmed by X-ray diffraction and electron microcopy. The reaction resulted in formation of Ba-deficient perovskite at the exposed surface. The reaction with CO2 was most pronounced at 650 ºC compared to the other temperatures applied in the study. The reactivity was also shown to depend on the Y-content and the grain size and was most pronounced for BaZr0.9Y0.1O3-δ. The reaction with CO2 was observed to have a profound effect on the fracture toughness of the ceramics, demonstrating a depression of the mechanical stability of the materials. The results are discussed with respect to the chemical and mechanical stability of BaZrO3 materials, with particular emphasis on the composition and grain size.

show abstract

Processing of yttrium-doped barium zirconate for high proton conductivity

Cited by 405 publications

References 28 publications

Comparative Study of BaY_0.1Zr_0.9O_3-δProtective Layers Deposited to BaY_0.1Ce_0.9O_3-δMembrane Using Ultrasonic Spray Pyrolysis and Magnetron Sputtering Methods

Comparative Study of BaY_0.1Zr_0.9O_3-δProtective Layers Deposited to BaY_0.1Ce_0.9O_3-δMembrane Using Ultrasonic Spray Pyrolysis and Magnetron Sputtering Methods

A Sensitive and Self-Regenerable Particulate Matter Sensor with a H₃PO₄-Modified BaZr_0.8Y_0.2O_3-δElectrolyte and an IrO₂-Catalyzed Sensing Electrode

Effect of CO₂ Exposure on the Chemical Stability and Mechanical Properties of BaZrO₃‐Ceramics

Contact Info

Product

Resources

About

Processing of yttrium-doped barium zirconate for high proton conductivity

Cited by 405 publications

References 28 publications

Comparative Study of BaY0.1Zr0.9O3-δProtective Layers Deposited to BaY0.1Ce0.9O3-δMembrane Using Ultrasonic Spray Pyrolysis and Magnetron Sputtering Methods

Comparative Study of BaY0.1Zr0.9O3-δProtective Layers Deposited to BaY0.1Ce0.9O3-δMembrane Using Ultrasonic Spray Pyrolysis and Magnetron Sputtering Methods

A Sensitive and Self-Regenerable Particulate Matter Sensor with a H3PO4-Modified BaZr0.8Y0.2O3-δElectrolyte and an IrO2-Catalyzed Sensing Electrode

Effect of CO2 Exposure on the Chemical Stability and Mechanical Properties of BaZrO3‐Ceramics

Contact Info

Product

Resources

About

Comparative Study of BaY_0.1Zr_0.9O_3-δProtective Layers Deposited to BaY_0.1Ce_0.9O_3-δMembrane Using Ultrasonic Spray Pyrolysis and Magnetron Sputtering Methods

Comparative Study of BaY_0.1Zr_0.9O_3-δProtective Layers Deposited to BaY_0.1Ce_0.9O_3-δMembrane Using Ultrasonic Spray Pyrolysis and Magnetron Sputtering Methods

A Sensitive and Self-Regenerable Particulate Matter Sensor with a H₃PO₄-Modified BaZr_0.8Y_0.2O_3-δElectrolyte and an IrO₂-Catalyzed Sensing Electrode

Effect of CO₂ Exposure on the Chemical Stability and Mechanical Properties of BaZrO₃‐Ceramics