Proton Conductivity of Compositionally Graded Proton Conducting Oxides

2003 ◽  
Vol 423-425 ◽  
pp. 441-444
Author(s):  
S. Yamaguchi ◽  
Takaaki Shishido ◽  
Mamoru Omori ◽  
A. Okubo ◽  
Satoru Yamamoto
Keyword(s):  
Proton Conductivity ◽  
Proton Conducting ◽  
Conducting Oxides

Acceptor doping in the proton conductor SrZrO3

2017 ◽  
Vol 19 (18) ◽  
pp. 11485-11491 ◽  
Author(s):  
Leigh Weston ◽  
A. Janotti ◽  
X. Y. Cui ◽  
C. Stampfl ◽  
C. G. Van de Walle
Keyword(s):  
Proton Conductivity ◽  
Proton Conductor ◽  
Acceptor Doping ◽  
Proton Conducting ◽  
Conducting Oxides

Acceptor dopants in proton-conducting oxides act as proton traps, or can accidentally incorporate as donors, reducing proton conductivity.

Strontium-substituted Ba(Ce,Zr)O3-δ oxides for proton conducting membranes

2014 ◽  
Vol 07 (06) ◽  
pp. 1440014 ◽  
Author(s):  
Wojciech Zając ◽  
Emil Hanc
Keyword(s):  
Crystal Lattice ◽  
Proton Conductivity ◽  
Chemical Stability ◽  
Full Range ◽  
Proton Conducting ◽  
Conducting Oxides ◽  
Lattice Symmetry ◽  
Order Of Magnitude ◽  
Conducting Membranes

This paper is focused on Ba 1-x Sr x( Ce 0.75 Zr 0.25)0.9 Nd 0.1 O 2.95 proton-conducting oxides, for which the effect of substitution of barium by strontium in a full range of compositions is studied. Crystal lattice symmetry, proton conductivity and stability in CO 2 atmosphere are discussed. Substitution of barium by strontium reduces toxicity and does not deteriorate chemical stability, however, crystal lattice of the strontium-substituted perovskites is more distorted, causing reduction of proton conductivity more than one order of magnitude. Balance between opposite tendencies can be found at low Sr content, e.g., 25 at.%.

Interaction of H2O, O2 and H2 with Proton Conducting Oxides Based on Lanthanum Scandates

2019 ◽  
pp. 88-100
Author(s):  
A. S. Farlenkov ◽  
N. A. Zhuravlev ◽  
Т. A. Denisova ◽  
М. V. Ananyev
Keyword(s):  
Water Vapor ◽  
Partial Pressure ◽  
Gas Phase ◽  
Molecular Hydrogen ◽  
Proton Magnetic Resonance ◽  
Partial Pressure Of Oxygen ◽  
Proton Conducting ◽  
Conducting Oxides ◽  
Temperature Range ◽  
Apparent Level

The research uses the method of high-temperature thermogravimetric analysis to study the processes of interaction of the gas phase in the temperature range 300–950 °C in the partial pressure ranges of oxygen 8.1–50.7 kPa, water 6.1–24.3 kPa and hydrogen 4.1 kPa with La1–xSrxScO3–α oxides (x = 0; 0.04; 0.09). In the case of an increase in the partial pressure of water vapor at a constant partial pressure of oxygen (or hydrogen) in the gas phase, the apparent level of saturation of protons is shown to increase. An increase in the apparent level of saturation of protons of the sample also occurs with an increase in the partial pressure of oxygen at a constant partial pressure of water vapor in the gas phase. The paper discusses the causes of the observed processes. The research uses the hydrogen isotope exchange method with the equilibration of the isotope composition of the gas phase to study the incorporation of hydrogen into the structure of proton-conducting oxides based on strontium-doped lanthanum scandates. The concentrations of protons and deuterons were determined in the temperature range of 300–800 °C and a hydrogen pressure of 0.2 kPa for La0.91Sr0.09ScO3–α oxide. The paper discusses the role of oxygen vacancies in the process of incorporation of protons and deuterons from the atmosphere of molecular hydrogen into the structure of the proton conducting oxides La1–xSrxScO3–α (x = 0; 0.04; 0.09). The proton magnetic resonance method was used to study the local structure in the temperature range 23–110 °C at a rotation speed of 10 kHz (MAS) for La0.96Sr0.04ScO3–α oxide after thermogravimetric measurements in an atmosphere containing water vapor, and after exposures in molecular hydrogen atmosphere. The existence of proton defects incorporated into the volume of the investigated proton oxide from both the atmosphere containing water and the atmosphere containing molecular hydrogen is unambiguously shown. The paper considers the effect of the contributions of the volume and surface of La0.96Sr0.04ScO3–α oxide on the shape of the proton magnetic resonance spectra.

scholarly journals Direct-Hydrocarbon Proton-Conducting Solid Oxide Fuel Cells

2021 ◽  
Vol 13 (9) ◽  
pp. 4736
Author(s):  
Fan Liu ◽  
Chuancheng Duan
Keyword(s):  
Fuel Cells ◽  
Solid Oxide Fuel Cells ◽  
Solid Oxide ◽  
Sulfur Poisoning ◽  
Oxide Fuel ◽  
Power Sources ◽  
Proton Conducting ◽  
Conducting Oxides ◽  
Operating Temperatures ◽  
Ion Conducting

Solid oxide fuel cells (SOFCs) are promising and rugged solid-state power sources that can directly and electrochemically convert the chemical energy into electric power. Direct-hydrocarbon SOFCs eliminate the external reformers; thus, the system is significantly simplified and the capital cost is reduced. SOFCs comprise the cathode, electrolyte, and anode, of which the anode is of paramount importance as its catalytic activity and chemical stability are key to direct-hydrocarbon SOFCs. The conventional SOFC anode is composed of a Ni-based metallic phase that conducts electrons, and an oxygen-ion conducting oxide, such as yttria-stabilized zirconia (YSZ), which exhibits an ionic conductivity of 10−3–10−2 S cm−1 at 700 °C. Although YSZ-based SOFCs are being commercialized, YSZ-Ni anodes are still suffering from carbon deposition (coking) and sulfur poisoning, ensuing performance degradation. Furthermore, the high operating temperatures (>700 °C) also pose challenges to the system compatibility, leading to poor long-term durability. To reduce operating temperatures of SOFCs, intermediate-temperature proton-conducting SOFCs (P-SOFCs) are being developed as alternatives, which give rise to superior power densities, coking and sulfur tolerance, and durability. Due to these advances, there are growing efforts to implement proton-conducting oxides to improve durability of direct-hydrocarbon SOFCs. However, so far, there is no review article that focuses on direct-hydrocarbon P-SOFCs. This concise review aims to first introduce the fundamentals of direct-hydrocarbon P-SOFCs and unique surface properties of proton-conducting oxides, then summarize the most up-to-date achievements as well as current challenges of P-SOFCs. Finally, strategies to overcome those challenges are suggested to advance the development of direct-hydrocarbon SOFCs.

Proton Conducting Compound of Benzimidazole with Sebacic Acid: Structure, Molecular Dynamics, and Proton Conductivity

2014 ◽  
Vol 14 (3) ◽  
pp. 1211-1220 ◽  
Author(s):  
Adam Rachocki ◽  
Katarzyna Pogorzelec-Glaser ◽  
Paweł Ławniczak ◽  
Maria Pugaczowa-Michalska ◽  
Andrzej Łapiński ◽  
...  
Keyword(s):  
Molecular Dynamics ◽  
Proton Conductivity ◽  
Sebacic Acid ◽  
Proton Conducting ◽  
Acid Structure

scholarly journals Proton-conducting Organic-inorganic Sulfo-containing Membranes for Fuel Cell

2021 ◽  
Author(s):  
Inga GRIGORAVICIUTE-PURONIENE ◽  
Iryna YEVCHUK ◽  
Oksana DEMCHYNA ◽  
Mariia ZHYHAILO ◽  
Khrystyna RYMSHA ◽  
...  
Keyword(s):  
Proton Conductivity ◽  
Sol Gel ◽  
Structural Heterogeneity ◽  
Silica Content ◽  
Inorganic Materials ◽  
Inorganic Component ◽  
Proton Conducting ◽  
Glycol Diacrylate ◽  
Silica Membranes ◽  
Component Content

Cross-linked organiс-inorganic sulfo-containing membranes of various compositions based on acrylic monomers (acrylonitrile, acrylic acid, 3-sulfopropylacrylate potassium salt, ethylene glycol diacrylate) and sol-gel systems of tetraethoxysilane have been developed. Synthesis of the polymer matrix was carried out by UV-initiated polymerization of the monomer mixture and the inorganic component was formed in situ while conducting the sol-gel process of the precursor. FTIR, SEM, EDS, DMA, impedance spectroscopy were used to characterize the synthesized materials. The influence of inorganic component content on the properties of the membranes was investigated. DMA results show that an increase in silica content leads to a decrease in packing density and an increase in structural heterogeneity in sulfo-containing polyacrylate/silica membranes. The highest values of proton conductivity 1.12 ꞏ 10−2 Sm/cm at 60 °C were found in membranes containing 3 wt.%. of the added sol-gel system. Further increase of silica content does not increase the proton conductivity of the membranes. The proton transfer activation energies in the membranes were calculated from the temperature dependence of proton conductivity. The obtained cross-linked sulfo-containing organic-inorganic materials can be used for the development of proton-conducting membranes for fuel cells.

scholarly journals ELECTRO-OSMOTIC FRACTIONATION OF HYDROGEN ISOTOPES IN ELECTROLYTIC SOLUTIONS USING COMPOSITE PROTON-PERMEABLE MEMBRANES

2021 ◽  
pp. 11-16
Author(s):  
O. Pushkar'ov ◽  
A. Zubko ◽  
I. Sevruk ◽  
V. Dolin
Keyword(s):  
Hydrogen Bonds ◽  
Proton Conductivity ◽  
Tritiated Water ◽  
High Mobility ◽  
Hydrogen Isotopes ◽  
Water Molecules ◽  
Proton Conducting ◽  
Partial Dissociation ◽  
Surface Modified ◽  
Conducting Membranes

Based on the analysis of the features of electroosmotic processes that are implemented in proton-conducting membranes, the possibility of fractioning hydrogen isotopes in electrolytes formed using tritiated water (HTO) is estimated. The interaction of the solution with the membranes in their channels leads to polarization and partial dissociation of the electrolyte molecules. In water molecules, when protium is replaced by a heavy isotope of hydrogen, the energy of breaking of hydrogen bonds increases and the process of their dissociation proceeds predominantly according to the scheme: HTO ↔ H+ + TO—. A part of the released protons can join water molecules to form the H3O+ ion. H3O+ and TO— ions are more mobile than other singly charged ions. The main characteristic that determines the suitability of electroosmotic membranes to the fractionation of hydrogen isotopes is proton conductivity. The released protons have anomalously high mobility due to their small size, tunnel and relay movement through hydrogen bonds between adjacent polar groups in the channels of the proton-conducting membranes. To ensure high proton conductivity in the pores and channels of the membranes, modifying substances are fixed, which contain the groups: –ОН- , –NH2, –NH, –SH, –COOH, –SO3H, acid salts and oxides, containing surface proton-conducting groups. To create proton-conducting membranes, it is possible to use surface-modified β-alumina (β-Al2O3(H3O+)) and protonated (H3O+) montmorillonite with ionic conductivity (5х103 – 4х104 Ohm х cm–1). The most effective are surface modifiers with negatively charged sulfonic groups. The imposition of an external electric field leads to the movement of ions in the electrolyte, which leads to a redistribution of the isotope ratio in the near-anode and cathode spaces.

scholarly journals Fabrication of multi-layered structures for proton conducting ceramic cells

2021 ◽  
Author(s):  
Wendelin Deibert ◽  
Mariya E. Ivanova ◽  
Yuanye Huang ◽  
Rotraut Merkle ◽  
Joachim Maier ◽  
...  
Keyword(s):  
Liquid Phase ◽  
Proton Conductivity ◽  
Phase Formation ◽  
Tape Casting ◽  
Transient Liquid Phase ◽  
Layered Structures ◽  
Proton Conducting

We show manufacturing of 25 cm2 BZCY half-cells by tape-casting of assemblies with electrolyte thickness 10–20 μm. BaY2NiO5 transient liquid phase formation is analysed and proton conductivity with values of σ = 0.003 S cm−1 at 600 °C is shown.

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