Electrode reactions at oxygen, noble metal / stabilized zirconia interfaces

Ionics ◽  
1996 ◽  
Vol 2 (2) ◽  
pp. 113-122 ◽  
Author(s):  
C. Schwandt ◽  
W. Weppner
Keyword(s):  
Noble Metal ◽  
Stabilized Zirconia ◽  
Electrode Reactions

Microstructure of sputter-deposited noble metal-incorporated oxide thin films patterned by means of laser interference

2011 ◽  
Vol 1339 ◽  
Author(s):  
Rodolphe Catrin ◽  
Thomas Gries ◽  
David Horwat ◽  
Sylvie Migot ◽  
Frank Muecklich
Keyword(s):  
Laser Treatment ◽  
Noble Metal ◽  
Film Surface ◽  
Solid Lubrication ◽  
Oxide Thin Film ◽  
Laser Interference ◽  
Stabilized Zirconia ◽  
Transmission Electron ◽  
Sputter Deposited ◽  
Fast Procedure

ABSTRACTLaser interference patterning-induced microstructural modifications have been investigated in two noble metal-incorporated oxide thin film systems: Pd0.25Pt0.75Ox and gold-incorporated yttria-stabilized zirconia - Au-YSZ. Transmission electron microscopy was used to investigate the influence of the laser treatment on the microstructure of the samples. In the case of Pd0.25Pt0.75Ox, the formation of a nanocomposite arrangement resulted from the precipitation of metal nanograins in the oxide matrix triggered by laser irradiation. In Au-YSZ, the starting microstructure consisted of gold nanograins embedded in a YSZ matrix. A noticeable growth and coalescence of gold nanograins occurred near the surface in the region of maximum interference. Simultaneously, a foamy morphology, mostly consisting of gold crystals, was formed at the film surface. In contrast to thermal annealing, the laser treatment proposed here is a fast procedure to partially relocate gold at the film surface and provide a local solid lubrication.

Analytical Electron Microscopy study of two vehicle-aged automotive exhaust catalysts having dissimilar activities

1989 ◽  
Vol 47 ◽  
pp. 272-273
Author(s):  
Sooho Kim ◽  
M. J. D’Aniello
Keyword(s):  
Electron Microscopy ◽  
Particle Size ◽  
Noble Metal ◽  
Catalyst Deactivation ◽  
Analytical Electron Microscopy ◽  
Microscopy Study ◽  
Metal Particles ◽  
Automotive Exhaust ◽  
Exhaust Catalysts ◽  
Analytical Electron

Automotive catalysts generally lose-agtivity during vehicle operation due to several well-known deactivation mechanisms. To gain a more fundamental understanding of catalyst deactivation, the microscopic details of fresh and vehicle-aged commercial pelleted automotive exhaust catalysts containing Pt, Pd and Rh were studied by employing Analytical Electron Microscopy (AEM). Two different vehicle-aged samples containing similar poison levels but having different catalytic activities (denoted better and poorer) were selected for this study.The general microstructure of the supports and the noble metal particles of the two catalysts looks similar; the noble metal particles were generally found to be spherical and often faceted. However, the average noble metal particle size on the poorer catalyst (21 nm) was larger than that on the better catalyst (16 nm). These sizes represent a significant increase over that found on the fresh catalyst (8 nm). The activity of these catalysts decreases as the observed particle size increases.

Effect of thermal annealing on grain boundary chemistry of polycrystalline TiBa2Ca2Cu3Oy films

1994 ◽  
Vol 52 ◽  
pp. 968-969
Author(s):  
Z. L. Wang ◽  
C. L. Briant ◽  
J. DeLuca ◽  
A. Goyal ◽  
D. M. Kroeger ◽  
...  
Keyword(s):  
Grain Boundary ◽  
Weak Link ◽  
Zero Field ◽  
Stabilized Zirconia ◽  
Local Texture ◽  
Transmission Electron ◽  
Axis Alignment ◽  
Boundary Chemistry ◽  
Small Misorientation ◽  
Misorientation Angles

Recent studies have shown that spray-pyrolyzed films of the Tl-1223 compound (TlxBa2Ca2Cu3Oy, with 0.7 < × < 0.95) on polycrystalline yttrium stabilized zirconia substrates can be prepared which have critical current density Jc near 105 A/cm2 at 77 K, in zero field. The films are polycrystalline, have excellent c-axis alignment, and show little evidence of weak-link behavior. Transmission electron microscopy (TEM) studies have shown that most grain boundaries have small misorientation angles. It has been found that the films have a nigh degree of local texture indicative of colonies of similarly oriented grains. It is believed that inter-colony conduction is enhanced by a percolative network of small angle boundaries at colony interfaces. It has also been found that Jc is increased by a factor of 4 - 5 after the films were annealed at 600 °C in oxygen. This study is thus carried out to determine the effect on grain boundary chemistry of the heat treatment.

Microstructural examination of modified yttria stabilized zirconia by EM analytical techniques

1986 ◽  
Vol 44 ◽  
pp. 842-843
Author(s):  
W. W. Davison ◽  
R. C. Buchanan
Keyword(s):  
Mechanical Properties ◽  
Analytical Techniques ◽  
Yttria Stabilized Zirconia ◽  
Stabilized Zirconia ◽  
Transmission Microscopy ◽  
Sintering Aid ◽  
Densification Temperature ◽  
Chemical Inertness ◽  
Scanning Transmission ◽  
Microstructural Examination

Yttria stabilized zirconia (YSZ) has become a significant technological material due to its high ionic conductivity, chemical inertness, and good mechanical properties. Temperatures on the order of 1700°C are required, however, to densify YSZ to the degree necessary for good electrical and mechanical properties. A technique for lowering the densification temperature is the addition of small amounts of material which facilitate the formation of a liquid phase at comparatively low temperatures. In this study, sintered microstructures obtained from the use of Al2O3 as a sintering aid were examined with scanning, transmission, and scanning transmission microscopy (SEM, TEM, and STEM).

Interlayer confinement synthesis of Ir nanodots/dual carbon as an electrocatalyst for overall water splitting

2020 ◽  
Author(s):  
Yaru Li ◽  
Yu-Quan Zhu ◽  
Weili Xin ◽  
Song Hong ◽  
Xiaoying Zhao ◽  
...  
Keyword(s):  
Water Splitting ◽  
Noble Metal ◽  
High Efficiency ◽  
Overall Water Splitting ◽  
Highly Dispersed

Rationally designing low-content and high-efficiency noble metal nanodots offers opportunities to enhance electrocatalytic performances for water splitting. However, the preparation of highly dispersed nanodots electrocatalysts remains a challenge. Herein, we...

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