High-Resolution TEM Characterization of Carbon Aerogels as Catalyst Supports

2003 ◽  
Vol 800 ◽  
Author(s):  
Dafei Kang ◽  
Ying Zhang ◽  
Carl Saquing ◽  
Can Erkey ◽  
Mark Aindow
Keyword(s):  
Structural Transition ◽  
Sol Gel ◽  
Thermal Reduction ◽  
Carbon Aerogels ◽  
Catalyst Supports ◽  
High Resolution Tem ◽  
Organometallic Precursors ◽  
Gel Processing

ABSTRACTCarbon aerogels with tailored pore sizes were prepared by using a combination of sol-gel processing, supercritical CO2 extraction and pyrolysis. Ruthenium particles were incorporated via impregnation of organometallic precursors using supercritical CO2, followed by in situ thermal reduction. TEM studies reveal that the carbon aerogels are characterized by a continuous pore structure and that the ruthenium particles are highly dispersed with a narrow size distribution. It is found that under certain circumstances the carbon aerogels undergo a structural transition under the electron beam, in which the original tortuous aerogel network transforms into onion-like structures.

Characterization Of Amorphous Gel To Superconducting Oxide Conversion For Sol-Gel Produced Y1Ba2Cu3O7-x.

1990 ◽  
Vol 180 ◽  
Author(s):  
G.A. Moore ◽  
D. Kenzer ◽  
M. Teepe ◽  
G. Kordas
Keyword(s):  
Heat Treatment ◽  
Sol Gel ◽  
Treatment Phase ◽  
Solvent System ◽  
Phase Development ◽  
In Situ Neutron Diffraction ◽  
Gel Processing ◽  
Oxide Conversion

ABSTRACTAlkoxide sol-gel processing of Y1Ba2Cu3O7-x was performed using copper(II) ethoxide, barium methoxyethoxide, and yttrium methoxyethoxide precursors in a methoxyethanol/methy ethyl ketone/toluene solvent system. In situ neutron diffraction experiments were performed on individual precursors and mixed component gels during heat treatment. Phase development and consumption was observed for both the calcination and annealing segments of the heat treatment. Formation of Y1Ba2Cu3O7-x was observed as early as 700°C. CuO, Cu2O, BaCuO, YCu2O5, BaCO3, BaCO4, and YlBa2Cu3O7-x were observed during the conversion/ consolidation reactions to 850°C.

scholarly journals Characterization of in-situ zirconia/mullite composites prepared by sol-gel technique

2021 ◽  
pp. 1-7
Author(s):  
Abdu. I. Abdallah ◽  
M. Sayed ◽  
M. Awaad ◽  
Adam H. E. Yousif ◽  
S.M. Naga
Keyword(s):  
Sol Gel ◽  
Gel Technique

Synthesis and characterization of BaMgAl10O17:Eu phosphors derived by sol–gel processing

2002 ◽  
Vol 126 (2) ◽  
pp. 161-165 ◽  
Author(s):  
Junying Zhang ◽  
Zhongtai Zhang ◽  
Zilong Tang ◽  
Zishan Zheng ◽  
Yuanhua Lin
Keyword(s):  
Sol Gel ◽  
Synthesis And Characterization ◽  
Gel Processing

Fabrication and Characterization of Sol-Gel Derived PZT/WO3 Ceramics

2008 ◽  
Vol 55-57 ◽  
pp. 369-372 ◽  
Author(s):  
T. Sreesattabud ◽  
Anucha Watcharapasorn ◽  
Sukanda Jiansirisomboon
Keyword(s):  
Lead Zirconate Titanate ◽  
Sol Gel ◽  
Rhombohedral Phase ◽  
Lead Zirconate ◽  
X Ray Diffraction ◽  
Calcination Process ◽  
Materials Used ◽  
Phase Characterization ◽  
Gel Processing

Lead zirconate titanate/tungsten oxide (PZT/WO3) ceramics were prepared from the powders synthesized by a modified triol sol-gel processing method. In this study, the starting materials used for synthesis of PZT-sol were zirconium (IV) propoxide, titanium (IV) isopropxide, lead (II) acetate trihydrate and 1,1,1,- tris (hydroxymethyl) ethane. To prepare PZT/xWO3 powders (where x = 0, 0.5, 1 and 3 wt%), nano-sized WO3 was ultrasonically dispersed and mixed with the PZT sol, dried and calcined at 600°C for 4 h. X-ray diffraction results indicated that fully crystallized powders were obtained. Phase characterization suggested that at high WO3 concentration, the reaction between PZT and WO3 occurred during the calcination process. To prepare PZT/xWO3 ceramics, the powders were pressed and sintered at 1100°C for 6 h. Phase characterization by XRD indicated that the content of WO3 significantly affected tetragonal-to-rhombohedral phase transition. Microstructure of thermally etched samples showed that increasing the content of WO3 decreased grain size of the ceramics.

scholarly journals Preparation and Characterization of Ta-substituted Li7La3Zr2-xO12 Garnet Solid Electrolyte by Sol-Gel Processing

2017 ◽  
Vol 54 (4) ◽  
pp. 278-284 ◽  
Author(s):  
Sang A Yoon ◽  
Nu Ri Oh ◽  
Ae Ri Yoo ◽  
Hee Gyun Lee ◽  
Hee Chul Lee
Keyword(s):  
Solid Electrolyte ◽  
Sol Gel ◽  
Gel Processing

scholarly journals Role of annealing temperature on the sol–gel synthesis of VO2 nanowires with in situ characterization of their metal–insulator transition

RSC Advances ◽  
2018 ◽  
Vol 8 (10) ◽  
pp. 5158-5165 ◽  
Author(s):  
Y.-R. Jo ◽  
S.-H. Myeong ◽  
B.-J. Kim
Keyword(s):  
Sol Gel ◽  
Insulator Transition ◽  
In Situ Characterization ◽  
Metal Insulator Transition ◽  
Metal Insulator ◽  
Nanowire Device ◽  
Sol Gel Synthesis

The single-VO2 nanowire device synthesized via sequential morphological evolutions with oxygen reduction during annealing features a sharp metal-insulator transition.

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