Results 301 to 310 of about 162,305 (348)

Stability of cubic zirconia and of stoichiometric zirconia nanoparticles

Physics of the Solid State, 2006
Using the electron density functional method, it is shown that the oxygen sublattice of cubic zirconia is unstable with respect to random displacements of oxygen atoms, which results in general instability of bulk cubic zirconia at low temperatures.
V. G. Zavodinsky, A. N. Chibisov
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Nature of hydrous zirconia and sulfated hydrous zirconia

Catalysis Today, 1994
Abstract The structure of crystalline hydrous zirconias and their methods of formation are described. A mechanism for the hydrolytic polymerization of Zr IV to obtain the several forms of hydrous oxide is presented. The method by which sulfate ion binds to the surface of zirconia particles is explored.
G.P.D. Serrette, A.H. Khazi-Syed, A. Clearfield   +2 more
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State of platinum in zirconia and sulfated zirconia catalysts

Catalysis Letters, 1996
Platinum is present in a metallic state following activation in air at 725‡C of both 5 wt% Pt/ZrO2 and 5 wt% Pt/SO 4 2− /ZrO2. Reduction of either catalyst at 725‡C produces a Pt-Zr alloy, and these reduced catalysts, upon recalcination in air at 725‡C, form metallic Pt crystallites.
Dennis E. Sparks, Ram Srinivasan, Burtron H. Davis   +2 more
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Nitridation of Zirconia [PDF]

Journal of the American Ceramic Society, 1996
ZrO2 can be nitrided partially by nitrogen at temperatures >1400°C. It is possible to describe all the synthesized phases with the general formula ZrO2‐2χN4χ/3 (system ZrO2‐Zr3N4). Parameters–such as nitridation time, temperature, nitrogen pressure, and particle size–have a strong effect on the amount of incorporated nitrogen.
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Nonstoichiometry of zirconia

Refractories, 1995
Phenomenological equations are suggested for describing the processes of disordering in electron and ion subsystems. Dependences of the concentration of point defects on the partial pressure of oxygen for each kind of defect are obtained in the course of the solution of the equations of defect formation due to the Schottky, Frenkel, and anti-Frenkel ...
V. E. Shvaiko-Shvaikovskii, Yu. N. Vil'k, V. A. Shvarts   +2 more
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Effects of zirconia phase on the synthesis of higher alcohols over zirconia and modified zirconia

Journal of Molecular Catalysis A: Chemical, 2004
The catalytic performances of ZrO2-based catalysts were evaluated for the synthesis of higher alcohols from synthesis gas. The crystal phase structures were characterized by X-ray diffraction (XRD) and UV Raman. The results indicated that ZrO2 and Pd modified ZrO2 catalysts were effective catalysts in the synthesis of ethanol or isobutanol, and their ...
Can Li, Hongyuan Luo, Daiping He, Yunjie Ding   +3 more
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Surface characterization of zirconia, holmium oxide/zirconia and sulfated zirconia catalysts

Colloids and Surfaces A: Physicochemical and Engineering Aspects, 2006
Abstract Zirconia-supported holmium oxide, as well as their sulfated catalysts using (NH 4 ) 2 SO 4 were prepared by wet impregnation and calcined at different temperatures. The samples thus obtained were subjected to bulk and surface texture analysis using X-ray powder diffractometry (XRD) and N 2 -sorptiometry, respectively.
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Creep behaviour of alumina, zirconia and zirconia-toughened alumina

Journal of the European Ceramic Society, 1997
no ...
Chevalier, Jérome, Olagnon, Christian, Fantozzi, Gilbert, Gros, H   +3 more
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Anodic Polarization Related to the Ionic Conductivity of Zirconia at Ni-Zirconia/Zirconia Electrodes

Journal of The Electrochemical Society, 2001
To clarify the extension of the triple phase boundary (TPB), which directly affects the electrode polarization behavior, in the cermet layer of the Ni zirconia anode, we studied the anodic polarization properties of four types of Ni-zirconia cermets (Ni-0YZC Ni-3YZC, and Ni-8YZC) on three types of zirconia electrolytes (3YZE, 5YZE, and 8YZE).
Nobuyoshi Nakagawa, Xiaoge Wang, Kunio Kato   +2 more
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Phase transformation of zirconia in sulfated zirconia–LiCl system

Materials Letters, 2007
Abstract The phase transformation from tetragonal to monoclinic of zirconia for a series of sulfated zirconia–LiCl samples was characterized by ultraviolet Raman spectroscopy (UVRS) and X-ray diffraction (XRD). Results show that such phase transformation increases with increasing LiCl content and the monoclinic phase is first detected by XRD than ...
Huilin Wan, Xiaohong Yuan, Chuanjing Huang, Chuanxiang Liu, Yubao Zhao, Yubao Zhao   +5 more
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