Oxygen Chemisorption, Formation, and Thermal Stability of Pt Oxides on Pt Nanoparticles Supported on SiO2/Si(001): Size Effects

2011 ◽  
Vol 115 (34) ◽  
pp. 16856-16866 ◽  
Author(s):  
Luis K. Ono ◽  
Jason R. Croy ◽  
Helge Heinrich ◽  
Beatriz Roldan Cuenya
Keyword(s):  
Thermal Stability ◽  
Size Effects ◽  
Pt Nanoparticles ◽  
Oxygen Chemisorption ◽  
Thermal Stability Of

scholarly journals In situ study of the thermal stability of supported Pt nanoparticles and their stabilization via atomic layer deposition overcoating

Nanoscale ◽  
2020 ◽  
Vol 12 (21) ◽  
pp. 11684-11693
Author(s):  
Eduardo Solano ◽  
Jolien Dendooven ◽  
Ji-Yu Feng ◽  
Philipp Brüner ◽  
Matthias M. Minjauw ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Atomic Layer Deposition ◽  
Pt Nanoparticles ◽  
Atomic Layer ◽  
Pt Nanoparticle ◽  
In Situ Study ◽  
Layer Deposition ◽  
Nanoparticle Stabilization ◽  
Thermal Stability Of

Supported Pt nanoparticle stabilization via Atomic Layer Deposition overcoating with Al2O3 has been proved to prevent particle coarsening during thermal annealing for widely spaced nanoparticles while ensuring surface accessibility for applications.

scholarly journals Graphene sheets manipulated the thermal-stability of ultrasmall Pt nanoparticles supported on porous Fe2O3nanocrystals against sintering

RSC Advances ◽  
2017 ◽  
Vol 7 (27) ◽  
pp. 16379-16386 ◽  
Author(s):  
Yunqian Dai ◽  
Xiaomian Qi ◽  
Wanlin Fu ◽  
Chengqian Huang ◽  
Shimei Wang ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Pt Nanoparticles ◽  
Catalyst System ◽  
Graphene Sheets ◽  
Thermal Stability Of

This study reports a new sinter-resistant catalyst system, consisting of Pt nanoparticles on Fe2O3rhombohedrons isolated by wrinkled graphene sheets.

Thermal Stability of Pt Nanoparticles Supported on WOx/Al2O3 for n-Heptane Hydroconversion

2010 ◽  
Vol 1279 ◽  
Author(s):  
J. L. Contreras ◽  
G.A. Fuentes ◽  
J. Salmones ◽  
B. Zeifert
Keyword(s):  
Thermal Stability ◽  
Bimetallic Catalysts ◽  
Pt Nanoparticles ◽  
Thermal Stabilization ◽  
Reaction Rates ◽  
Atomic Ratio ◽  
Impregnation Method ◽  
Reduction Temperature ◽  
Sequential Samples ◽  
Thermal Stability Of

AbstractThe thermal stabilization of γ-Al2O3 using W+6 ions has been found useful to the synthesis of Pt/Al2O3 catalysts. The sequential impregnation method was used to study the effect of W6+ upon Pt/ γ-Al2O3 reducibility, Pt dispersion, Raman spectroscopy and n-heptane hydroconversion. The W/Pt atomic ratios varied from 3.28 to 75. We found that the W6+ ions delayed reduction of a fraction of Pt+4 atoms beyond 773 K. At the same time, W6+inhibited sintering of the metallic crystallites once they were formed on the surface. For the sample with a W/Pt atomic ratio of 3.28, W6+ did not inhibit the H2 reduction of Pt oxides even below of 773 K, the Pt oxides were reduced completely, however, the Pt dispersion decreased for this sample with respect to the Pt/γ-Al2O3 catalyst. After reduction at 1073 K, sequential samples impregnating Pt on WOx/γAl2O3 were more active and stable during n-heptane hydroconversion than monometallic Pt/γAl2O3 catalyst. Selectivities for dehydrocyclization, isomerization and Hydrocracking changed significantly when the W/Pt atomic ratio and reduction temperature increased. Initial and final reaction rates were more sensitive to reduction temperature. W6+ ions promoted high thermal stability of Pt crystallites when sequential catalysts were reduced at 1073 K and deactivation of bimetallic catalysts reduced at 773 K and 1073 K was less than the deactivation of Pt/Al2O3 catalyst.

The Ordered Phase Formation in Ti-Al-Ga Alloys

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

Microstructure studies of tungsten silicide schottky contacts on Gaas

1987 ◽  
Vol 45 ◽  
pp. 328-329
Author(s):  
Yih-Cheng Shih ◽  
E. L. Wilkie
Keyword(s):  
Thermal Stability ◽  
Field Effect Transistors ◽  
Schottky Contact ◽  
Schottky Contacts ◽  
Excellent Thermal Stability ◽  
Barrier Heights ◽  
Gaas Substrates ◽  
Film Adhesion ◽  
Threshold Voltages ◽  
Thermal Stability Of

Tungsten silicides (WSix) have been successfully used as the gate materials in self-aligned GaAs metal-semiconductor-field- effect transistors (MESFET). Thermal stability of the WSix/GaAs Schottky contact is of major concern since the n+ implanted source/drain regions must be annealed at high temperatures (∼ 800°C). WSi0.6 was considered the best composition to achieve good device performance due to its low stress and excellent thermal stability of the WSix/GaAs interface. The film adhesion and the uniformity in barrier heights and ideality factors of the WSi0.6 films have been improved by depositing a thin layer of pure W as the first layer on GaAs prior to WSi0.6 deposition. Recently WSi0.1 has been used successfully as the gate material in 1x10 μm GaAs FET's on the GaAs substrates which were sputter-cleaned prior to deposition. These GaAs FET's exhibited uniform threshold voltages across a 51 mm wafer with good film adhesion after annealing at 800°C for 10 min.

Thermal stability of Al-Cu-Fe icosahedral alloys

1991 ◽  
Vol 1 (12) ◽  
pp. 1823-1836 ◽  
Author(s):  
M. Bessière ◽  
A. Quivy ◽  
S. Lefebvre ◽  
J. Devaud-Rzepski ◽  
Y. Calvayrac
Keyword(s):  
Thermal Stability ◽  
Thermal Stability Of

Practical criteria for the thermal stability of a unidimensional superconductor

1994 ◽  
Vol 4 (4) ◽  
pp. 653-657
Author(s):  
B. Bonzi ◽  
M. El Khomssi ◽  
H. Lanchon-Ducauquis
Keyword(s):  
Thermal Stability ◽  
Thermal Stability Of
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