Small angle X-ray scattering investigation of platinum metal dispersions on alumina catalysts

1972 ◽  
Vol 25 (3) ◽  
pp. 407-415 ◽  
Author(s):  
T WHYTE
Keyword(s):  
Small Angle ◽  
Platinum Metal ◽  
X Ray ◽  
X Ray Scattering ◽  
Alumina Catalysts ◽  
Ray Scattering

scholarly journals In situanomalous small-angle X-ray scattering from metal particles in supported-metal catalysts. II. Results

2005 ◽  
Vol 38 (2) ◽  
pp. 324-332 ◽  
Author(s):  
H. Brumberger ◽  
D. Hagrman ◽  
J. Goodisman ◽  
K. D. Finkelstein
Keyword(s):  
Small Angle ◽  
Platinum Metal ◽  
Metal Particles ◽  
Metal Catalyst ◽  
Supported Metal Catalysts ◽  
X Ray ◽  
Average Value ◽  
X Ray Scattering ◽  
Supported Metal ◽  
Ray Scattering

Information about the metal phase in a supported-metal catalyst can be obtained using anomalous small-angle X-ray scattering (ASAXS). The difference between the scattering profiles for SAXS at two different wavelengths near the metal's absorption edge is essentially the scattering of the metal alone. Novelin situASAXS measurements are made on mordenite impregnated with platinum metal while the temperature and composition of gas in the sample cell are changed. Measurements are made 62 times during treatment of the catalyst. The metal particles are assumed to be randomly distributed spheres withN(R)dR= number of spheres with radii betweenRandR+ dR. It is found thatN(R) is always a monotonically decreasing function ofR, and that the average value ofR, obtained fromN(R), decreases by a factor of two over the time (approximately 6 h) for which the system is observed.

scholarly journals In situanomalous small-angle X-ray scattering from metal particles in supported-metal catalysts. I. Theory

2005 ◽  
Vol 38 (1) ◽  
pp. 147-151 ◽  
Author(s):  
H. Brumberger ◽  
D. Hagrman ◽  
J. Goodisman ◽  
K. D. Finkelstein
Keyword(s):  
Small Angle ◽  
Platinum Metal ◽  
Metal Particles ◽  
Metal Catalyst ◽  
Supported Metal Catalysts ◽  
X Ray ◽  
Average Value ◽  
X Ray Scattering ◽  
Supported Metal ◽  
Ray Scattering

A supported-metal catalyst can be considered as a mixture of three homogeneous phases: support, void and metal. Information about the metal phase alone can be obtained using anomalous small-angle X-ray scattering (ASAXS), which requires measuring the SAXS for two different wavelengths near the metal's absorption edge. Herein, the conditions that must be obtained so that the difference between the two scattering profiles gives the scattering of the metal alone are presented. In a following contribution, the analysis will be applied toin situASAXS measurements made on mordenite impregnated with platinum metal while the temperature and composition of gas in the sample cell are changed. The metal particles are assumed to be randomly distributed spheres withN(R)dRbeing the number of spheres with radii betweenRandR+ dR. FromN(R) one can obtain the average value ofR.

A Revised O2 Reduction Model in Li-O2 Batteries as Revealed by in Situ Small Angle X-Ray Scattering

2019 ◽  
Author(s):  
Christian Prehal ◽  
Aleksej Samojlov ◽  
Manfred Nachtnebel ◽  
Manfred Kriechbaum ◽  
Heinz Amenitsch ◽  
...  
Keyword(s):  
Small Angle ◽  
Wide Angle ◽  
Reduction Mechanism ◽  
Reduction Model ◽  
X Ray ◽  
X Ray Scattering ◽  
O2 Reduction ◽  
Ray Scattering

<b>Here we use in situ small and wide angle X-ray scattering to elucidate unexpected mechanistic insights of the O2 reduction mechanism in Li-O2 batteries.<br></b>

In situ Time-Resolved Small-Angle X-ray Scattering Reveals the Formation Kinetics of Polyelectrolyte Complex Micelles

2019 ◽  
Author(s):  
Hao Wu ◽  
Jeffrey Ting ◽  
Siqi Meng ◽  
Matthew Tirrell
Keyword(s):  
Small Angle ◽  
Self Assembly ◽  
Electrostatic Interactions ◽  
Polyelectrolyte Complex ◽  
Time Resolved ◽  
X Ray ◽  
X Ray Scattering ◽  
Kinetics Of ◽  
Ray Scattering

We have directly observed the <i>in situ</i> self-assembly kinetics of polyelectrolyte complex (PEC) micelles by synchrotron time-resolved small-angle X-ray scattering, equipped with a stopped-flow device that provides millisecond temporal resolution. This work has elucidated one general kinetic pathway for the process of PEC micelle formation, which provides useful physical insights for increasing our fundamental understanding of complexation and self-assembly dynamics driven by electrostatic interactions that occur on ultrafast timescales.

Small angle X-ray scattering study of porosity variation in a styrene-divinylbenzene copolymer

1981 ◽  
Vol 46 (7) ◽  
pp. 1675-1681 ◽  
Author(s):  
Josef Baldrian ◽  
Božena N. Kolarz ◽  
Henrik Galina
Keyword(s):  
Small Angle ◽  
Structural Parameters ◽  
Two Phase ◽  
X Ray ◽  
Porosity Variation ◽  
Swelling Agent ◽  
X Ray Scattering ◽  
Styrene Divinylbenzene ◽  
Ray Scattering

Porosity variations induced by swelling agent exchange were studied in a styrene-divinylbenzene copolymer. Standard methods were used in the characterization of copolymer porosity in the dry state and the results were compared with related structural parameters derived from small angle X-ray scattering (SAXS) measurements as developed for the characterization of two-phase systems. The SAXS method was also used for porosity determination in swollen samples. The differences in the porosity of dry samples were found to be an effect of the drying process, while in the swollen state the sample swells and deswells isotropically.

Mirror to measure small angle x-ray scattering signal in high energy density experiments

2020 ◽  
Vol 91 (12) ◽  
pp. 123501
Author(s):  
M. Šmíd ◽  
C. Baehtz ◽  
A. Pelka ◽  
A. Laso García ◽  
S. Göde ◽  
...  
Keyword(s):  
Energy Density ◽  
Small Angle ◽  
High Energy ◽  
High Energy Density ◽  
X Ray ◽  
X Ray Scattering ◽  
Scattering Signal ◽  
Ray Scattering
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