Ni-Infiltrated Spherical Porcelain Support as Potential Steam Reforming Microchannel Reactor.

This paper describes the fabrication of kaolinite (AlO-2SiO-2HO) spherical bulbs by slip casting. The bisque-fired parts present a porosity of about 30% with submicron porosity confirmed by scanning electron microscopy. In addition, plate-like grains with channels were observed.

Slip Casting and Solid-State Reactive Sintering of BCZY(BaCeZrYO)-NiO/BCZY Half-Cells.

Slip casting was used to prepare BaCeZrYO(BCZY)-NiO tubes with a diameter of ½ inches (1.25 cm) and ¾ inches (1.875 cm).

Modeling Electro-Chemo-Mechanical Behaviors within the Dense BaZrYO Protonic-Ceramic Membrane in a Long Tubular Electrochemical Cell.

This paper reports an extended Nernst-Planck computational model that couples charged-defect transport and stress in tubular electrochemical cell with a ceramic proton-conducting membrane. The model is particularly concerned with coupled chemo-mechanical behaviors, including how electrochemical phenomena affect internal stresses and vice versa. The computational model predicts transient and steady-state defect concentrations, fluxes, stresses within a thin BaZrYO (BZY20) membrane.

The effect of grain size on the hydration of BaZrYO proton conductor studied by ambient pressure X-ray photoelectron spectroscopy.

Three BaZr0.9Y0.1O3-δ (BZY10) pellets were prepared using different sintering processes, resulting in samples with different grain sizes, from 0.

Channelized Substrates Made from BaZrCeYO Proton-Conducting Ceramic Polymer Clay.

A novel process for producing thick protonic ceramics for use in hydrogen separation membrane reactors is demonstrated. Polymer clay bodies based on polyvinyl acetate (PVA) and mineral oil were formulated, and they permitted parts with complex architectures to be prepared by simple, low-pressure molding in the unfired, "green" state. Ceramic proton conductors based on doped barium zirconate/cerate, made by solid-state reactive sintering, are particularly well-suited for the polymer clay process.

Thermodynamic Insights for Electrochemical Hydrogen Compression with Proton-Conducting Membranes.

Membrane electrode assemblies (MEA) based on proton-conducting electrolyte membranes offer opportunities for the electrochemical compression of hydrogen. Mechanical hydrogen compression, which is more-mature technology, can suffer from low reliability, noise, and maintenance costs. Proton-conducting electrolyte membranes may be polymers (e.

Assessing Substitution Effects on Surface Chemistry by in Situ Ambient Pressure X-ray Photoelectron Spectroscopy on Perovskite Thin Films, BaCe ZrYO ( x = 0; 0.2; 0.9).

Performance of proton-solid oxide fuel cells (H-SOFC) is governed by ion transport through solid/gas interfaces. Major breakthroughs are then intrinsically linked to a detailed understanding of how parameters tailoring bulk proton conductivity affect surface chemistry in situ, at an early stage. In this work, we studied proton and oxygen transport at the interface between H-SOFC electrolyte BaCe ZrYO ( x = 0; 0.

Highly durable, coking and sulfur tolerant, fuel-flexible protonic ceramic fuel cells.

Protonic ceramic fuel cells, like their higher-temperature solid-oxide fuel cell counterparts, can directly use both hydrogen and hydrocarbon fuels to produce electricity at potentially more than 50 per cent efficiency. Most previous direct-hydrocarbon fuel cell research has focused on solid-oxide fuel cells based on oxygen-ion-conducting electrolytes, but carbon deposition (coking) and sulfur poisoning typically occur when such fuel cells are directly operated on hydrocarbon- and/or sulfur-containing fuels, resulting in severe performance degradation over time. Despite studies suggesting good performance and anti-coking resistance in hydrocarbon-fuelled protonic ceramic fuel cells, there have been no systematic studies of long-term durability.

Effect of Cation Ordering on the Performance and Chemical Stability of Layered Double Perovskite Cathodes.

The effect of A-site cation ordering on the cathode performance and chemical stability of A-site cation ordered LaBaCo₂O and disordered LaBaCoO materials are reported. Symmetric half-cells with a proton-conducting BaZrYO electrolyte were prepared by ceramic processing, and good chemical compatibility of the materials was demonstrated. Both A-site ordered LaBaCo₂O and A-site disordered LaBaCoO yield excellent cathode performance with Area Specific Resistances as low as 7.

Probing Grain-Boundary Chemistry and Electronic Structure in Proton-Conducting Oxides by Atom Probe Tomography.

A laser-assisted atom-probe-tomographic (LAAPT) method has been developed and applied to measure and characterize the three-dimensional atomic and electronic nanostructure at an yttrium-doped barium zirconate (BaZrYO, BZY10) grain boundary. Proton-conducting perovskites, such as BZY10, are attracting intense interest for a variety of energy conversion applications. However, their implementation has been hindered, in part, because of high grain-boundary (GB) resistance that is attributed to a positive GB space-charge layer (SCL).

Interpreting equilibrium-conductivity and conductivity-relaxation measurements to establish thermodynamic and transport properties for multiple charged defect conducting ceramics.

A model-based interpretation of measured equilibrium conductivity and conductivity relaxation is developed to establish thermodynamic, transport, and kinetics parameters for multiple charged defect conducting (MCDC) ceramic materials. The present study focuses on 10% yttrium-doped barium zirconate (BZY10). In principle, using the Nernst-Einstein relationship, equilibrium conductivity measurements are sufficient to establish thermodynamic and transport properties.

Readily processed protonic ceramic fuel cells with high performance at low temperatures.

Because of the generally lower activation energy associated with proton conduction in oxides compared to oxygen ion conduction, protonic ceramic fuel cells (PCFCs) should be able to operate at lower temperatures than solid oxide fuel cells (250° to 550°C versus ≥600°C) on hydrogen and hydrocarbon fuels if fabrication challenges and suitable cathodes can be developed. We fabricated the complete sandwich structure of PCFCs directly from raw precursor oxides with only one moderate-temperature processing step through the use of sintering agents such as copper oxide. We also developed a proton-, oxygen-ion-, and electron-hole-conducting PCFC-compatible cathode material, BaCo(0.