SiO2 (core)-TiO2 (shell) Structure as Catalyst Support for Oxidation of CO at Low Temperatures

2007 ◽  
Vol 334-335 ◽  
pp. 1025-1028
Author(s):  
Zi Yi Zong ◽  
Xi Jiang Yin ◽  
Li Fang Lew ◽  
Soo Yee Tan
Keyword(s):  
Thermal Stability ◽  
Catalytic Activity ◽  
Shell Structure ◽  
Low Temperatures ◽  
Au Nanoparticles ◽  
Catalyst Support ◽  
High Thermal Stability ◽  
Core Shell ◽  
Oxidation Of Co ◽  
Core Shell Structure

In this study, TiO2 was successfully coated on Stober silica beads followed by depositing Au nanoparticles on this core-shell structure. The size of the Au nanoparticles was well controlled in the range of 2 – 7 nm. This composite exhibited high thermal stability. When used as a model catalyst for oxidation of CO at low temperatures, the Au/TiO2/SiO2 showed a much higher catalytic activity than the Au/SiO2 and Au/TiO2(P25) catalysts.

scholarly journals Direct Imaging of Core-shell Structure in Ag-Au Nanoparticles

2005 ◽  
Vol 11 (S02) ◽  
Author(s):  
Z Y Li ◽  
J Yuan ◽  
Y Chen ◽  
R Palmer ◽  
J Wilcoxon
Keyword(s):  
Shell Structure ◽  
Au Nanoparticles ◽  
Core Shell ◽  
Direct Imaging ◽  
Core Shell Structure

Preparation, Characterization and Visible-Light Catalytic Activity of Core-Shell Structure NiFe2O4@TiO2 Ferrite Nanoparticles

2016 ◽  
Vol 680 ◽  
pp. 272-277
Author(s):  
Zhou Li Lu ◽  
Peng Zhao Gao ◽  
Rui Xue Ma ◽  
Yu Kun Sun ◽  
Dong Yun Li
Keyword(s):  
Catalytic Activity ◽  
Visible Light ◽  
Shell Structure ◽  
Shell Thickness ◽  
Spinel Ferrite ◽  
Sol Gel ◽  
Magnetic Core ◽  
Core Shell ◽  
Calcination Temperatures ◽  
Core Shell Structure

The core-shell structure NiFe2O4@TiO2 nanoparticles was successfully prepared using a sol-gel method, the influence of shell thickness and calcination temperatures on the composition, microstructure, magnetic properties and visible-light catalytic activity of the nanoparticles was studied by XRD, TEM, Uv–vis, vibrating sample magnetometer, etc. Results showed the main composition of core in NiFe2O4@TiO2 was spinel ferrite, and the shell was anatase TiO2, and theshell thickness increased significantly with the increase of TiO2 content, ranging from 10nm to 50nm. The Ms and Mr of nanoparticles decreased with the increase of TiO2 content, and no obvious reaction between the magnetic core and shell occurred; visible-light degradation percent of NiFe2O4@TiO2 nanoparticles increased along with the increase of TiO2 content, whereas the recovery rate of it decreased. Degradation percent and the recovery percent of NiFe2O4@TiO2-50 still reached 93.7% and 90.5%, even after 10 cycle times, respectively, possessing the excellent long-term stability.

Nanocomposites of CsPbBr3 perovskite nanocrystals in an ammonium bromide framework with enhanced stability

2017 ◽  
Vol 5 (30) ◽  
pp. 7431-7435 ◽  
Author(s):  
Sunqi Lou ◽  
Tongtong Xuan ◽  
Caiyan Yu ◽  
Mengmeng Cao ◽  
Chao Xia ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Ion Exchange ◽  
Shell Structure ◽  
Water Resistance ◽  
Ammonium Bromide ◽  
Core Shell ◽  
Excellent Thermal Stability ◽  
Long Lifetime ◽  
Core Shell Structure ◽  
Enhanced Stability

The CsPbBr3@NH4Br nanocomposites were successfully synthesized through ion exchange. The nanocomposites possessed a special core@shell structure and exhibited a high absolute PLQY, long lifetime, good water resistance and excellent thermal stability.

scholarly journals Core/Shell Structure of TiO2-Coated MWCNTs for Thermal Protection for High-Temperature Processing of Metal Matrix Composites

2018 ◽  
Vol 2018 ◽  
pp. 1-11 ◽  
Author(s):  
Laura Angélica Ardila Rodriguez ◽  
Dilermando Nagle Travessa
Keyword(s):  
Thermal Stability ◽  
Metal Matrix Composites ◽  
Shell Structure ◽  
Metal Matrix ◽  
Thermal Protection ◽  
Oxidation Stability ◽  
Core Shell ◽  
Matrix Composites ◽  
X Ray ◽  
Core Shell Structure

The production of metal matrix composites with elevated mechanical properties depends largely on the reinforcing phase properties. Due to the poor oxidation resistance of multiwalled carbon nanotubes (MWCNTs) as well as their high reactivity with molten metal, the processing conditions for the production of MWCNT-reinforced metal matrix composites may be an obstacle to their successful use as reinforcement. Coating MWCNTs with a ceramic material that acts as a thermal protection would be an alternative to improve oxidation stability. In this work, MWCNTs previously functionalized were coated with titanium dioxide (TiO2) layers of different thicknesses, producing a core-shell structure. Heat treatments at three different temperatures (500°C, 750°C, and 1000°C) were performed on coated nanotubes in order to form a stable metal oxide structure. The MWCNT/TiO2 hybrids produced were evaluated in terms of thermal stability. Thermogravimetric analysis (TGA), X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy (RS), and X-ray photoelectron spectroscopy (XPS) were performed in order to investigate TiO2-coated MWCNT structure and thermal stability under oxidative atmosphere. It was found that the thermal stability of the TiO2-coated MWCNTs was dependent of the TiO2 layer morphology that in turn depends on the heat treatment temperature.

One-pot synthesis of Au–Fe2O3@SiO2 core–shell nanoreactors for CO oxidation

2020 ◽  
Vol 44 (15) ◽  
pp. 5661-5665
Author(s):  
Hongbo Yu ◽  
Zhengtong Guo ◽  
Chunzheng Wu ◽  
Shujian Wang ◽  
Bin Li ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Co Oxidation ◽  
High Activity ◽  
Shell Structure ◽  
Core Shell ◽  
One Pot ◽  
Good Thermal Stability ◽  
One Pot Synthesis ◽  
Core Shell Structure

The combination of the Au–Fe2O3 phase and core–shell structure helps in achieving high activity and good thermal stability.

Enhanced catalytic activity of cobalt nanoparticles encapsulated with an N-doped porous carbon shell derived from hollow ZIF-8 for efficient synthesis of nitriles from primary alcohols in water

2019 ◽  
Vol 21 (16) ◽  
pp. 4334-4340 ◽  
Author(s):  
Kang-kang Sun ◽  
Jia-lin Sun ◽  
Guo-Ping Lu ◽  
Chun Cai
Keyword(s):  
Catalytic Activity ◽  
Shell Structure ◽  
Cobalt Catalyst ◽  
Cobalt Nanoparticles ◽  
Core Shell ◽  
Efficient Synthesis ◽  
Primary Alcohols ◽  
Mild Conditions ◽  
Core Shell Structure ◽  
Unique Core

A cobalt catalyst derived from a unique core–shell structure based on hollow ZIF-8 and ZIF-67 is prepared for the synthesis of nitriles from alcohols in water under mild conditions.

Characterization of Core-Shell Structure Palygorskite Modified by Nano-CaCO3 (PnC) Composite Particles

2013 ◽  
Vol 750-752 ◽  
pp. 348-351
Author(s):  
Di Fang Zhao ◽  
Ming Hua Li ◽  
Jin Song Xie
Keyword(s):  
Thermal Stability ◽  
Shell Structure ◽  
Composite Particles ◽  
Core Shell ◽  
X Ray Diffraction ◽  
Stability Properties ◽  
Structure Morphology ◽  
Palygorskite Clay ◽  
Core Shell Structure

In this work, Core-shell structure palygorskite/nanoCaCO3(PnC) composite particles have been synthesized chemically, employing solution precipitation methods. Crystal structure, morphology and thermal stability properties are investigated by means of X-ray diffraction (XRD), transmission electronic microscopy (TEM) and Thermogravimetric (TG) analysis. The results showed that the PnC particles were almost monodispersed microsphere aspect with the size was about 1-3 μm diameter. The nanocomposite particles exhibit the marked thermal stability properties than the palygorskite clay mineral.

Tuning the Band Structure of MoS2 via Co9S8@MoS2 Core–Shell Structure to Boost Catalytic Activity for Lithium–Sulfur Batteries

ACS Nano ◽  
2020 ◽  
Vol 14 (12) ◽  
pp. 17285-17294
Author(s):  
Boyu Li ◽  
Qingmei Su ◽  
Lintao Yu ◽  
Jun Zhang ◽  
Gaohui Du ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Band Structure ◽  
Shell Structure ◽  
Core Shell ◽  
Lithium Sulfur Batteries ◽  
Core Shell Structure ◽  
Lithium Sulfur
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