Mössbauer and Exafs Study of 57Fe Labelled Pt/SiO2 Catalysts

1987 ◽  
Vol 111 ◽  
Author(s):  
J. A. Sawicki ◽  
J. H. Rolston ◽  
S. R. Julian ◽  
T. Tyliszczak ◽  
K. D. McCrimmon
Keyword(s):  
Carbon Monoxide ◽  
Nitrate Solution ◽  
Ferric Nitrate ◽  
Ambient Temperatures ◽  
Highly Dispersed ◽  
Exafs Study ◽  
Microstructural Studies ◽  
Ferric Nitrate Solution ◽  
Absorption Measurements

AbstractSpecimens of highly dispersed Pt/Silicalite catalyst, decorated with 57Fe by impregnation in aqueous ferric nitrate solution, have been studied after decoration, and various pretreatments including exposure to carbon monoxide, by in situ Mössbauer spectroscopy. The form of Pt was followed by EXAFS analysis near the Pt LIII edge. The microstructural studies were combined with CO chemisorption and infrared absorption measurements. It is observed that iron in Pt clusters is very reactive even at ambient temperatures and that the interaction of Fe with CO is strongly accelerated by platinum.

Remarkably enhanced water splitting activity of nickel foam due to simple immersion in a ferric nitrate solution

Nano Research ◽  
2018 ◽  
Vol 11 (8) ◽  
pp. 3959-3971 ◽  
Author(s):  
Huajie Yin ◽  
Lixue Jiang ◽  
Porun Liu ◽  
Mohammad Al-Mamun ◽  
Yun Wang ◽  
...  
Keyword(s):  
Water Splitting ◽  
Nickel Foam ◽  
Nitrate Solution ◽  
Ferric Nitrate ◽  
Ferric Nitrate Solution

scholarly journals Enhanced Tensile Strength of Monolithic Epoxy with Highly Dispersed TiO2-Graphene Nanocomposites

2021 ◽  
Vol 5 (7) ◽  
pp. 191
Author(s):  
Yanshuai Wang ◽  
Siyao Guo ◽  
Biqin Dong ◽  
Feng Xing
Keyword(s):  
Tensile Strength ◽  
Epoxy Resin ◽  
Mechanical Performance ◽  
Chemical Properties ◽  
High Mechanical Property ◽  
Graphene Nanocomposites ◽  
Highly Dispersed ◽  
Dispersion State ◽  
Physical And Chemical

The functionalization of graphene has been reported widely, showing special physical and chemical properties. However, due to the lack of surface functional groups, the poor dispersibility of graphene in solvents strongly limits its engineering applications. This paper develops a novel green “in-situ titania intercalation” method to prepare a highly dispersed graphene, which is enabled by the generation of the titania precursor between the layer of graphene at room temperature to yield titania-graphene nanocomposites (TiO2-RGO). The precursor of titania will produce amounts of nano titania between the graphene interlayers, which can effectively resist the interfacial van der Waals force of the interlamination in graphene for improved dispersion state. Such highly dispersed TiO2-RGO nanocomposites were used to modify epoxy resin. Surprisingly, significant enhancement of the mechanical performance of epoxy resin was observed when incorporating the titania-graphene nanocomposites, especially the improvements in tensile strength and elongation at break, with 75.54% and 176.61% increases at optimal usage compared to the pure epoxy, respectively. The approach presented herein is easy and economical for industry production, which can be potentially applied to the research of high mechanical property graphene/epoxy composite system.

scholarly journals Improvement of mechanical properties of HfB2-based composites by incorporating in situ SiC reinforcement through pressureless sintering

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
S. Ghadami ◽  
E. Taheri-Nassaj ◽  
H. R. Baharvandi ◽  
F. Ghadami
Keyword(s):  
Mechanical Properties ◽  
Thermal Conductivity ◽  
Relative Density ◽  
Pressureless Sintering ◽  
Sintering Process ◽  
Vacuum Atmosphere ◽  
Sic Reinforcement ◽  
Microstructural Studies ◽  
Composite Samples

AbstractHfB2, Si, and activated carbon powders were selected to fabricate 0–30 vol% SiC reinforced HfB2-based composite. Pressureless sintering process was performed at 2050 °C for 4 h under a vacuum atmosphere. Microstructural studies revealed that in situ SiC reinforcement was formed and distributed in the composite according to the following reaction: Si + C = SiC. A maximum relative density of 98% was measured for the 20 vol% SiC containing HfB2 composite. Mechanical investigations showed that the hardness and the fracture toughness of these composites were increased and reached up to 21.2 GPa for HfB2-30 vol% SiC and 4.9 MPa.m1/2 for HfB2-20 vol% SiC, respectively. Results showed that alpha-SiC reinforcements were created jagged, irregular, and elongated in shape which were in situ formed between HfB2 grains and filled the porosities. Formation of alpha-SiC contributed to improving the relative density and mechanical properties of the composite samples. By increasing SiC content, an enhanced trend of thermal conductivity was observed as well as a reduced trend for electrical conductivity.

Development of a new methodology for the retrieval of in-situ stratospheric trace gases concentration from airborne limb-absorption measurements

2002 ◽  
Author(s):  
Andrea Petritoli ◽  
Giorgio Giovanelli ◽  
Fabrizio Ravegnani ◽  
Daniele Bortoli ◽  
Ivan K. Kostadinov ◽  
...  
Keyword(s):  
Trace Gases ◽  
Stratospheric Trace Gases ◽  
Absorption Measurements
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