scholarly journals Addressing the characterisation challenge to understand catalysis in MOFs: the case of nanoscale Cu supported in NU-1000

2017 ◽  
Vol 201 ◽  
pp. 337-350 ◽  
Author(s):  
Ana E. Platero-Prats ◽  
Zhanyong Li ◽  
Leighanne C. Gallington ◽  
Aaron W. Peters ◽  
Joseph T. Hupp ◽  
...  
Keyword(s):  
Dynamic Structure ◽  
Atomic Layer ◽  
Scattering Data ◽  
Catalyst Activation ◽  
Reducing Atmosphere ◽  
X Ray Scattering ◽  
Layer Deposition ◽  
Pdf Analysis ◽  
Catalytically Active

We explore the dynamic structure and reactivity of Cu species supported on NU-1000. By combining pair distribution function (PDF) analysis and difference envelope density (DED) analysis of in situ synchrotron-based X-ray scattering data, we simultaneously probe the local structure of supported Cu-species, their distribution within NU-1000 and distortions of the NU-1000 lattice under conditions relevant to catalysis and catalyst activation. These analyses show that atomic layer deposition (ALD) of Cu in NU-1000 (Cu-AIM) leads to the formation of Cu-oxo clusters within the small pores that connect the triangular and hexagonal channels. Exposure of Cu-AIM to a reducing atmosphere at 200 °C produces metallic Cu0 of two distinct particle sizes: ∼4 nm nanoparticles and small sub-nanometer clusters. The size of these nanoparticles appears to be constrained by NU-1000 pore dimensions, with evidence of the sub-nanometer clusters being bound within the triangular channels flanked by pyrene rings. This supported Cu0–NU-1000 system is catalytically active for gas-phase ethylene hydrogenation. Exposure of the catalyst to oxidative atmosphere re-oxidises the Cu species to a Cu2O cuprite phase. The dynamic restructuring of the system in different chemical environments underscores the importance of probing these systems in situ.

In-Situ Synchrotron X-Ray Scattering Study of Thin Film Growth by Atomic Layer Deposition

2011 ◽  
Vol 11 (2) ◽  
pp. 1577-1580 ◽  
Author(s):  
Yong Jun Park ◽  
Dong Ryeol Lee ◽  
Hyun Hwi Lee ◽  
Han-Bo-Ram Lee ◽  
Hyungjun Kim ◽  
...  
Keyword(s):  
Thin Film ◽  
Atomic Layer Deposition ◽  
Film Growth ◽  
Atomic Layer ◽  
Thin Film Growth ◽  
X Ray ◽  
X Ray Scattering ◽  
Layer Deposition ◽  
Scattering Study

scholarly journals A new method for in situ structural investigations of nano-sized amorphous and crystalline materials using mixed-flow reactors

2019 ◽  
Vol 75 (5) ◽  
pp. 758-765 ◽  
Author(s):  
Alexandria Hoeher ◽  
Sebastian Mergelsberg ◽  
Olaf J. Borkiewicz ◽  
Patricia M. Dove ◽  
F. Marc Michel
Keyword(s):  
Flow Reactor ◽  
Calcium Phosphates ◽  
Scattering Data ◽  
Mixed Flow ◽  
Structural Investigations ◽  
X Ray ◽  
X Ray Scattering ◽  
Pdf Analysis ◽  
Ray Scattering

Structural investigations of amorphous and nanocrystalline phases forming in solution are historically challenging. Few methods are capable of in situ atomic structural analysis and rigorous control of the system. A mixed-flow reactor (MFR) is used for total X-ray scattering experiments to examine the short- and long-range structure of phases in situ with pair distribution function (PDF) analysis. The adaptable experimental setup enables data collection for a range of different system chemistries, initial supersaturations and residence times. The age of the sample during analysis is controlled by adjusting the flow rate. Faster rates allow for younger samples to be examined, but if flow is too fast not enough data are acquired to average out excess signal noise. Slower flow rates form older samples, but at very slow speeds particles settle and block flow, clogging the system. Proper background collection and subtraction is critical for data optimization. Overall, this MFR method is an ideal scheme for analyzing the in situ structures of phases that form during crystal growth in solution. As a proof of concept, high-resolution total X-ray scattering data of amorphous and crystalline calcium phosphates and amorphous calcium carbonate were collected for PDF analysis.

scholarly journals Atomic layer deposition-based tuning of the pore size in mesoporous thin films studied by in situ grazing incidence small angle X-ray scattering

Nanoscale ◽  
2014 ◽  
Vol 6 (24) ◽  
pp. 14991-14998 ◽  
Author(s):  
Jolien Dendooven ◽  
Kilian Devloo-Casier ◽  
Matthias Ide ◽  
Kathryn Grandfield ◽  
Mert Kurttepeli ◽  
...  
Keyword(s):  
Thin Films ◽  
Pore Size ◽  
Small Angle ◽  
Atomic Layer ◽  
Grazing Incidence ◽  
X Ray ◽  
X Ray Scattering ◽  
Layer Deposition ◽  
Mesoporous Thin Films

Atomic Layer Deposition of LiF and Lithium Ion Conducting (AlF3)(LiF)x Alloys Using Trimethylaluminum, Lithium Hexamethyldisilazide and Hydrogen Fluoride

2017 ◽  
Author(s):  
Younghee Lee ◽  
Daniela M. Piper ◽  
Andrew S. Cavanagh ◽  
Matthias J. Young ◽  
Se-Hee Lee ◽  
...  
Keyword(s):  
Lithium Ion ◽  
Atomic Layer ◽  
Mass Gain ◽  
Alloy Film ◽  
Ex Situ ◽  
X Ray ◽  
Layer Deposition ◽  
Ion Conducting ◽  
Good Agreement

<div>Atomic layer deposition (ALD) of LiF and lithium ion conducting (AlF<sub>3</sub>)(LiF)<sub>x</sub> alloys was developed using trimethylaluminum, lithium hexamethyldisilazide (LiHMDS) and hydrogen fluoride derived from HF-pyridine solution. ALD of LiF was studied using in situ quartz crystal microbalance (QCM) and in situ quadrupole mass spectrometer (QMS) at reaction temperatures between 125°C and 250°C. A mass gain per cycle of 12 ng/(cm<sup>2</sup> cycle) was obtained from QCM measurements at 150°C and decreased at higher temperatures. QMS detected FSi(CH<sub>3</sub>)<sub>3</sub> as a reaction byproduct instead of HMDS at 150°C. LiF ALD showed self-limiting behavior. Ex situ measurements using X-ray reflectivity (XRR) and spectroscopic ellipsometry (SE) showed a growth rate of 0.5-0.6 Å/cycle, in good agreement with the in situ QCM measurements.</div><div>ALD of lithium ion conducting (AlF3)(LiF)x alloys was also demonstrated using in situ QCM and in situ QMS at reaction temperatures at 150°C A mass gain per sequence of 22 ng/(cm<sup>2</sup> cycle) was obtained from QCM measurements at 150°C. Ex situ measurements using XRR and SE showed a linear growth rate of 0.9 Å/sequence, in good agreement with the in situ QCM measurements. Stoichiometry between AlF<sub>3</sub> and LiF by QCM experiment was calculated to 1:2.8. XPS showed LiF film consist of lithium and fluorine. XPS also showed (AlF<sub>3</sub>)(LiF)x alloy consists of aluminum, lithium and fluorine. Carbon, oxygen, and nitrogen impurities were both below the detection limit of XPS. Grazing incidence X-ray diffraction (GIXRD) observed that LiF and (AlF<sub>3</sub>)(LiF)<sub>x</sub> alloy film have crystalline structures. Inductively coupled plasma mass spectrometry (ICP-MS) and ionic chromatography revealed atomic ratio of Li:F=1:1.1 and Al:Li:F=1:2.7: 5.4 for (AlF<sub>3</sub>)(LiF)<sub>x</sub> alloy film. These atomic ratios were consistent with the calculation from QCM experiments. Finally, lithium ion conductivity (AlF<sub>3</sub>)(LiF)<sub>x</sub> alloy film was measured as σ = 7.5 × 10<sup>-6</sup> S/cm.</div>

Coupling In-Situ Techniques to Analyze Zinc Deposition and Dissolution for Energy Storage Applications

2013 ◽  
Vol 1491 ◽  
Author(s):  
Jayme Keist ◽  
Christine Orme ◽  
Frances Ross ◽  
Dan Steingart ◽  
Paul Wright ◽  
...  
Keyword(s):  
Liquid Electrolyte ◽  
Scattering Data ◽  
Zinc Deposition ◽  
Ionic Liquid Electrolyte ◽  
Force Microscopy ◽  
In Situ Techniques ◽  
X Ray Scattering ◽  
Atomic Force ◽  
Afm Analysis

ABSTRACTThis investigation describes preliminary results of in-situ analysis of zinc deposition within an ionic liquid electrolyte utilizing electrochemical atomic force microscopy (EC AFM). From the AFM analysis, the morphology of the zinc deposition was analyzed by quantifying the surface roughness using height-height correlation functions. These results will be used to analyze the scattering data obtained from zinc deposition analysis utilizing an electrochemical ultra-small angle x-ray scattering (EC USAXS). The goal of this research is to link the early nucleation and growth behavior to the formation of detrimental morphologies.

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