In situ infrared and EXAFS studies of an Ag cluster in zeolite X

Polyhedron ◽  
2005 ◽  
Vol 24 (5) ◽  
pp. 685-691 ◽  
Author(s):  
Yushi Suzuki ◽  
Naoyuki Matsumoto ◽  
Takeshi Ainai ◽  
Takafumi Miyanaga ◽  
Hideoki Hoshino
Keyword(s):  
Zeolite X ◽  
Ag Cluster

Local structure change of luminescent Ag zeolite-A and -X studied by in situ XAFS and IR spectroscopy

2020 ◽  
Vol 27 (6) ◽  
pp. 1640-1647
Author(s):  
Takafumi Miyanaga ◽  
Yushi Suzuki ◽  
Sho Narita ◽  
Reki Nakamura
Keyword(s):  
Local Structure ◽  
Room Temperature ◽  
Structural Changes ◽  
Zeolite A ◽  
Zeolite X ◽  
Zeolite Cavity ◽  
Ag Clusters ◽  
The Difference ◽  
X Ray Absorption

The in situ X-ray absorption fine structure (XAFS) for the structural changes of Ag clusters produced in the cavity of luminescent zeolites by thermal treatment of Ag zeolite-A and Ag zeolite-X has been studied. The following procedures are compared: (i) samples are heated and cooled to room temperature under atmosphere (under air); (ii) samples are heated and cooled to room temperature in a vacuum and then exposed to air. It was confirmed that the Ag clusters were broken when the Ag zeolite was exposed to air for Ag zeolite-X, which complements our previous results for Ag12-A. It is suggested that the deformation of the Ag clusters plays an important role in the generation of a strong photoluminescence band, and Ag clusters may not be direct species producing the strong photoluminescence. The local structure of the Ag ions was found to be slightly different from that of the unheated species. The difference may originate from the formation and breakdown of Ag clusters in the zeolite cavity.

In-situ Pair Distribution Function Study of the Growth of Supported Platinum Particles in Zeolite X

2014 ◽  
Vol 1712 ◽  
Author(s):  
Liliana M. Gámez ◽  
Oscar Resto ◽  
Maria M. Martinez-Inesta
Keyword(s):  
Distribution Function ◽  
Pair Distribution Function ◽  
High Energy ◽  
X Ray Diffraction ◽  
Zeolite X ◽  
Time Resolved ◽  
Supported Platinum ◽  
Platinum Particles ◽  
Dehydrogenation Reactions

ABSTRACTPlatinum particles supported in zeolites are used as catalysts for hydrogenation/ dehydrogenation reactions. In this study in situ high energy synchrotron X-ray diffraction was used to study the Pt particle formation under calcination and reduction conditions using time resolved pair distribution function (PDF). Because these particles grow inside the pores of zeolite X, PDF is able to give insight to unique information at the short and medium interatomic distance range that cannot be readily obtained with other techniques. Among the information obtained are the Pt atom interactions during calcination and the evolvement of the Pt particle sizes and average Pt-Pt distances during reduction.

In situ ultrasonic diagnostic of zeolite X crystallization with novel (hierarchical) morphology from coal fly ash

Ultrasonics ◽  
2014 ◽  
Vol 54 (2) ◽  
pp. 537-543 ◽  
Author(s):  
Nicholas M. Musyoka ◽  
Leslie F. Petrik ◽  
Eric Hums ◽  
Hasan Baser ◽  
Wilhelm Schwieger
Keyword(s):  
Fly Ash ◽  
Coal Fly Ash ◽  
Zeolite X ◽  
Hierarchical Morphology

scholarly journals In Situ Hydrothermal Conversion of Silica Gel Precursors to Binderless Zeolite X Pellets for Enhanced Olefin Adsorption

Authorea ◽  
2020 ◽  
Author(s):  
Hao Jiang ◽  
Dan Wang ◽  
Jialun Tan ◽  
Yuxiang Chen ◽  
Yang An ◽  
...  
Keyword(s):  
Silica Gel ◽  
Zeolite X ◽  
Hydrothermal Conversion

In Situ UV Raman Spectroscopic Studies on the Synthesis Mechanism of Zeolite X

2008 ◽  
Vol 14 (17) ◽  
pp. 5125-5129 ◽  
Author(s):  
Fengtao Fan ◽  
Zhaochi Feng ◽  
Guanna Li ◽  
Keju Sun ◽  
Pinliang Ying ◽  
...  
Keyword(s):  
Spectroscopic Studies ◽  
Zeolite X ◽  
Synthesis Mechanism ◽  
Raman Spectroscopic ◽  
Uv Raman

In Situ Hydrothermal Conversion of Silica Gel Precursors to Binderless Zeolite X Pellets for Enhanced Olefin Adsorption

2020 ◽  
Vol 59 (21) ◽  
pp. 9997-10009
Author(s):  
Hao Jiang ◽  
Dan Wang ◽  
Jialun Tan ◽  
Yuxiang Chen ◽  
Yang An ◽  
...  
Keyword(s):  
Silica Gel ◽  
Zeolite X ◽  
Hydrothermal Conversion

Formation of Ag clusters in zeolite X studied by in situ EXAFS and infrared spectroscopy

2013 ◽  
Vol 168 ◽  
pp. 213-220 ◽  
Author(s):  
Takafumi Miyanaga ◽  
Yushi Suzuki ◽  
Naoyuki Matsumoto ◽  
Sho Narita ◽  
Takeshi Ainai ◽  
...  
Keyword(s):  
Infrared Spectroscopy ◽  
Zeolite X ◽  
Ag Clusters ◽  
In Situ Exafs

Rendez vous with Saturn's rings

1984 ◽  
Vol 75 ◽  
pp. 743-759 ◽  
Author(s):  
Kerry T. Nock
Keyword(s):  
Solar Energy ◽  
Electric Propulsion ◽  
Power Source ◽  
Propulsion System ◽  
Low Thrust ◽  
Ring Plane ◽  
The Earth ◽  
Total Impulse ◽  
Saturn's Rings

ABSTRACTA mission to rendezvous with the rings of Saturn is studied with regard to science rationale and instrumentation and engineering feasibility and design. Future detailedin situexploration of the rings of Saturn will require spacecraft systems with enormous propulsive capability. NASA is currently studying the critical technologies for just such a system, called Nuclear Electric Propulsion (NEP). Electric propulsion is the only technology which can effectively provide the required total impulse for this demanding mission. Furthermore, the power source must be nuclear because the solar energy reaching Saturn is only 1% of that at the Earth. An important aspect of this mission is the ability of the low thrust propulsion system to continuously boost the spacecraft above the ring plane as it spirals in toward Saturn, thus enabling scientific measurements of ring particles from only a few kilometers.

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