scholarly journals Time-resolved operando studies of carbon supported Pd nanoparticles under hydrogenation reactions by X-ray diffraction and absorption

2018 ◽  
Vol 208 ◽  
pp. 187-205 ◽  
Author(s):  
Aram L. Bugaev ◽  
Oleg A. Usoltsev ◽  
Andrea Lazzarini ◽  
Kirill A. Lomachenko ◽  
Alexander A. Guda ◽  
...  
Keyword(s):  
Pd Nanoparticles ◽  
X Ray Diffraction ◽  
Time Resolved ◽  
X Ray ◽  
Hydrogenation Reactions ◽  
X Ray Absorption ◽  
Supported Pd ◽  
Comprehensive Study ◽  
Operando Studies

We present a comprehensive study of a 5 wt% Pd/C catalyst in various environments by using in situ and operando X-ray absorption and diffraction.

A dispenser–reactor apparatus applied forin situXAS monitoring of Pt nanoparticle formation

2015 ◽  
Vol 22 (3) ◽  
pp. 736-744 ◽  
Author(s):  
Jocenir Boita ◽  
Marcus Vinicius Castegnaro ◽  
Maria do Carmo Martins Alves ◽  
Jonder Morais
Keyword(s):  
Photoelectron Spectroscopy ◽  
Metallic Nanoparticles ◽  
Pt Nanoparticles ◽  
Lattice Parameter ◽  
X Ray Diffraction ◽  
Time Resolved ◽  
X Ray ◽  
Two Stages ◽  
X Ray Absorption

In situtime-resolved X-ray absorption spectroscopy (XAS) measurements collected at the PtL3-edge during the synthesis of Pt nanoparticles (NPs) in aqueous solution are reported. A specially designed dispenser–reactor apparatus allowed for monitoring changes in the XAS spectra from the earliest moments of Pt ions in solution until the formation of metallic nanoparticles with a mean diameter of 4.9 ± 1.1 nm. By monitoring the changes in the local chemical environment of the Pt atoms in real time, it was possible to observe that the NPs formation kinetics involved two stages: a reduction-nucleation burst followed by a slow growth and stabilization of NPs. Subsequently, the synthesized Pt NPs were supported on activated carbon and characterized by synchrotron-radiation-excited X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD) and extended X-ray absorption fine structure (EXAFS). The supported Pt NPs remained in the metallic chemical state and with a reduced size, presenting slight lattice parameter contraction in comparison with the bulk Pt values.

Phase Transition Analysis between LiFePO4and FePO4by In-Situ Time-Resolved X-ray Absorption and X-ray Diffraction

2013 ◽  
Vol 160 (5) ◽  
pp. A3061-A3065 ◽  
Author(s):  
Yuki Orikasa ◽  
Takehiro Maeda ◽  
Yukinori Koyama ◽  
Taketoshi Minato ◽  
Haruno Murayama ◽  
...  
Keyword(s):  
Phase Transition ◽  
X Ray Diffraction ◽  
Transition Analysis ◽  
Time Resolved ◽  
X Ray ◽  
X Ray Absorption

scholarly journals Expanding the Mechanochemical Toolbox: Combining X-Ray Absorption Spectroscopy and Scattering for in Situ Time-Resolved Monitoring of Gold Nanoparticle Mechanosynthesis

2020 ◽  
Author(s):  
Paulo F M de Oliveira ◽  
Adam Michalchuk ◽  
Ana de Oliveira Guilherme Buzanich ◽  
Ralf Bienert ◽  
Roberto M. Torresi ◽  
...  
Keyword(s):  
Absorption Spectroscopy ◽  
Electronic Materials ◽  
Early Stage ◽  
X Ray Diffraction ◽  
Time Resolved ◽  
Subsequent Formation ◽  
X Ray ◽  
Detection Capabilities ◽  
X Ray Absorption

<div>The development of time-resolved in situ approaches for monitoring mechanochemical</div><div>transformations has revolutionized the field of mechanochemistry. Currently, the established in</div><div>situ approaches greatly limit the scope of investigations that are possible. Here we develop a new</div><div>approach to simultaneously follow the evolution of bulk atomic and electronic structure during a</div><div>mechanochemical synthesis. This is achieved by coupling two complementary synchrotron-based</div><div>X-ray methods: X-ray absorption spectroscopy and X-ray diffraction. We apply this method to</div><div>investigate the bottom-up mechanosynthesis of technologically important Au nanoparticles in the</div><div>presence of three different reducing agents. Moreover, we demonstrate how X-ray absorption</div><div>spectroscopy offers unprecedented insight into the early stage generation of growth species (e.g.</div><div>monomers and clusters), which lead to the subsequent formation of nanoparticles. These</div><div>processes are beyond the detection capabilities of diffraction methods. The approach is general,</div><div>and not limited to monitoring NP mechanosynthesis. This combined X-ray approach paves the</div><div>way to new directions in mechanochemical research of advanced electronic materials.</div>

A reaction cell for time-resolvedin situXAS studies during wet chemical synthesis: the Cu2(OH)3Cl case

2013 ◽  
Vol 21 (1) ◽  
pp. 254-258 ◽  
Author(s):  
Jocenir Boita ◽  
Maria do Carmo Martins Alves ◽  
Jonder Morais
Keyword(s):  
Chemical Synthesis ◽  
Photoelectron Spectroscopy ◽  
X Ray Diffraction ◽  
Reaction Cell ◽  
Time Resolved ◽  
X Ray ◽  
Wet Chemical Synthesis ◽  
X Ray Absorption ◽  
Electronic And Structural Properties

The use ofin situtime-resolved dispersive X-ray absorption spectroscopy (DXAS) to monitor the formation of Cu2(OH)3Cl particles in an aqueous solution is reported. The measurements were performed using a dedicated reaction cell, which enabled the evolution of the CuK-edge X-ray absorption near-edge spectroscopy to be followed during mild chemical synthesis. The formed Cu2(OH)3Cl particles were also characterized by synchrotron-radiation-excited X-ray photoelectron spectroscopy, X-ray diffraction and scanning electron microscopy. The influence of polyvinylpyrrolidone (PVP) on the electronic and structural properties of the formed particles was investigated. The results indicate clearly the formation of Cu2(OH)3Cl, with or without the use of PVP, which presents very similar crystalline structures in the long-range order. However, depending on the reaction, dramatic differences were observed byin situDXAS in the vicinities of the Cu atoms.

Thermal Evolution of Carbon-Supported Pd Nanoparticles Studied by Time-Resolved X-ray Diffraction

2001 ◽  
Vol 105 (34) ◽  
pp. 8088-8091 ◽  
Author(s):  
Patrizia Canton ◽  
Carlo Meneghini ◽  
Pietro Riello ◽  
Antonella Balerna ◽  
Alvise Benedetti
Keyword(s):  
Thermal Evolution ◽  
Pd Nanoparticles ◽  
X Ray Diffraction ◽  
Time Resolved ◽  
X Ray ◽  
Supported Pd

scholarly journals Expanding the Mechanochemical Toolbox: Combining X-Ray Absorption Spectroscopy and Scattering for in Situ Time-Resolved Monitoring of Gold Nanoparticle Mechanosynthesis

2020 ◽  
Author(s):  
Paulo F M de Oliveira ◽  
Adam Michalchuk ◽  
Ana de Oliveira Guilherme Buzanich ◽  
Ralf Bienert ◽  
Roberto M. Torresi ◽  
...  
Keyword(s):  
Absorption Spectroscopy ◽  
Electronic Materials ◽  
Early Stage ◽  
X Ray Diffraction ◽  
Time Resolved ◽  
Subsequent Formation ◽  
X Ray ◽  
Detection Capabilities ◽  
X Ray Absorption

<div>The development of time-resolved in situ approaches for monitoring mechanochemical</div><div>transformations has revolutionized the field of mechanochemistry. Currently, the established in</div><div>situ approaches greatly limit the scope of investigations that are possible. Here we develop a new</div><div>approach to simultaneously follow the evolution of bulk atomic and electronic structure during a</div><div>mechanochemical synthesis. This is achieved by coupling two complementary synchrotron-based</div><div>X-ray methods: X-ray absorption spectroscopy and X-ray diffraction. We apply this method to</div><div>investigate the bottom-up mechanosynthesis of technologically important Au nanoparticles in the</div><div>presence of three different reducing agents. Moreover, we demonstrate how X-ray absorption</div><div>spectroscopy offers unprecedented insight into the early stage generation of growth species (e.g.</div><div>monomers and clusters), which lead to the subsequent formation of nanoparticles. These</div><div>processes are beyond the detection capabilities of diffraction methods. The approach is general,</div><div>and not limited to monitoring NP mechanosynthesis. This combined X-ray approach paves the</div><div>way to new directions in mechanochemical research of advanced electronic materials.</div>

In situ time resolved wide angle X-ray diffraction study of nanotube carpet growth: Nature of catalyst particles and progressive nanotube alignment

Carbon ◽  
2015 ◽  
Vol 87 ◽  
pp. 246-256 ◽  
Author(s):  
Périne Landois ◽  
Mathieu Pinault ◽  
Stéphan Rouzière ◽  
Dominique Porterat ◽  
Cristian Mocuta ◽  
...  
Keyword(s):  
Diffraction Study ◽  
Wide Angle ◽  
X Ray Diffraction ◽  
Time Resolved ◽  
X Ray
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