Improved thermal stability of a copper-containing ceria-based catalyst for low temperature CO oxidation under simulated diesel exhaust conditions

Hydroxyapatite (HA) was synthesized in presence of 20wt% m-ZrO2by solid state reaction between tricalcium phosphate(TCP) and Ca(OH)2at 1000 °C for 2h. Similarily, Fluorine hydroxyapatite(FA) was synthesized using tricalcium phosphate and calcium fluoride as raw materials at 1000 °Cfor 3h. The as-prepared HA was mixed with 10%,25%,45%,55%,70wt% FA and the mixture was sintered at 1000°C-1400°C for 2h. The main phase and bulk density was measured. The results show that when the relative amount of FA to HA increased, the decomposition of the composite is decreased gradually because of the formation of thermally stable FHA solid solutions. Low temperature would effect the exchange of ionic between FA and HA,while high temperature would impact synthesis of composites, because high temperature would lead to dissolution of HA ,which has to react with FA. Increase the content of HA would be advantage for synthesis FHA-ZrO2composite.

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The effect of high-temperature pre-treatment and water on the low temperature CO oxidation with Au/Fe2O3 catalysts

Catalysis Letters ◽

10.1007/s10562-004-3083-z ◽

2005 ◽

Vol 100 (1-2) ◽

pp. 39-47 ◽

Cited By ~ 51

Author(s):

S.T. Daniells ◽

M. Makkee ◽

J.A. Moulijn

Keyword(s):

High Temperature ◽

Low Temperature ◽

Co Oxidation ◽

Low Temperature Co Oxidation ◽

Pre Treatment

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Study of Grain Growth Kinetics in Submicrocrystalline Armco-Iron

Materials Science Forum ◽

10.4028/www.scientific.net/msf.550.465 ◽

2007 ◽

Vol 550 ◽

pp. 465-470 ◽

Cited By ~ 2

Author(s):

A.N. Aleshin ◽

Alex M. Arsenkin ◽

Sergey V. Dobatkin

Keyword(s):

Thermal Stability ◽

High Temperature ◽

Low Temperature ◽

Grain Growth ◽

Growth Kinetics ◽

Armco Iron ◽

High Temperature Annealing ◽

Grain Growth Kinetics ◽

Submicrocrystalline Materials ◽

Thermal Stability Of

The paper is devoted to the problem of thermal stability of ultra-fine grained (submicrocrystalline) materials prepared by severe plastic deformation. A basis of the paper lies in a fact that there is practically no grain growth in submicrocrystalline materials when annealing temperature is less than 0.35Tm. Reasons of high thermal stability of submicrocrystalline materials at low temperatures are widely discussed in literature. One of them is the affect of triple junction drag on grain boundaries motion. During annealing at a low temperature triple junction drag controls microstructure evolution in submicrocrystalline materials, and this phenomenon can be used to improve their thermal stability at high temperatures. The aim of this paper is to investigate grain growth kinetics in a two-step regime, low temperature and high temperature annealing. The experiments on grain growth were performed in submicrocrystalline Armco-iron fabricated by high pressure torsion. It is established that long-time low temperature pre-annealing reduces the grain growth rate in following high temperature annealing by a factor greater than two.

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Catalytic Studies on the Mixed Ceria-Zirconia Doped La3+, Pr3+ or Mn4+

Solid State Phenomena ◽

10.4028/www.scientific.net/ssp.121-123.323 ◽

2007 ◽

Vol 121-123 ◽

pp. 323-326

Author(s):

Ming Fen Wen ◽

D. Yang ◽

Jian Chen ◽

Ch.L. Song ◽

Yong Wan Gu

Keyword(s):

Thermal Stability ◽

Catalytic Activity ◽

High Temperature ◽

Low Temperature ◽

Redox Behavior ◽

Three Way Catalyst ◽

Calcined Temperature ◽

Thermal Stability Of

A number of experiments were carried out with different Ce-Zr oxides doped La3+、Pr3+ or Mn4+ in order to improve their performance as a promoter for three way catalyst(TWC). The XRD results showed that the thermal stability of Ce-Zr oxide doped lanthanum or praseodymium was improved, especially at high temperature. H2-TPR test detected the low –temperature redox behavior of Ce-Zr oxide was promoted strongly attributed to the MnO2, with calcined temperature increasing, the reduction peaks were moved to high temperature for Ce-Zr oxide doped La3+ and Pr3+. The catalytic activity of Ce-Zr oxide doped Mn4+ was also enhanced, the light-off temperature was lower 10K than Ce-Zr oxide; the conversions of CO and THC were higher 3-4% than Ce-Zr oxide.

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High-temperature diffusion induced high activity of SBA-15 supported Ag particles for low temperature CO oxidation at room temperature

Journal of Catalysis ◽

10.1016/j.jcat.2012.10.019 ◽

2013 ◽

Vol 297 ◽

pp. 264-271 ◽

Cited By ~ 61

Author(s):

Xiaodong Zhang ◽

Zhenping Qu ◽

Fangli Yu ◽

Yi Wang

Keyword(s):

High Temperature ◽

Low Temperature ◽

Co Oxidation ◽

High Activity ◽

Room Temperature ◽

Temperature Diffusion ◽

Ag Particles ◽

Low Temperature Co Oxidation

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The Ordered Phase Formation in Ti-Al-Ga Alloys

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100069193 ◽

1970 ◽

Vol 28 ◽

pp. 440-441

Author(s):

Shiro Fujishiro ◽

Harold L. Gegel

Keyword(s):

Thermal Stability ◽

High Temperature ◽

Titanium Alloys ◽

Growth Kinetics ◽

Stoichiometric Composition ◽

Good Potential ◽

Alpha Titanium ◽

Cold Rolled ◽

Kinetics Of ◽

Thermal Stability Of

Ordered-alpha titanium alloys having a DO19 type structure have good potential for high temperature (600°C) applications, due to the thermal stability of the ordered phase and the inherent resistance to recrystallization of these alloys. Five different Ti-Al-Ga alloys consisting of equal atomic percents of aluminum and gallium solute additions up to the stoichiometric composition, Ti3(Al, Ga), were used to study the growth kinetics of the ordered phase and the nature of its interface.The alloys were homogenized in the beta region in a vacuum of about 5×10-7 torr, furnace cooled; reheated in air to 50°C below the alpha transus for hot working. The alloys were subsequently acid cleaned, annealed in vacuo, and cold rolled to about. 050 inch prior to additional homogenization

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