scholarly journals Stabilization of a nanoporous NiCu dilute alloy catalyst for non-oxidative ethanol dehydrogenation

2020 ◽  
Vol 10 (15) ◽  
pp. 5207-5217
Author(s):  
Nare Janvelyan ◽  
Matthijs A. van Spronsen ◽  
Cheng Hao Wu ◽  
Zhen Qi ◽  
Matthew M. Montemore ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Photoelectron Spectroscopy ◽  
Ex Situ ◽  
Ethanol Dehydrogenation ◽  
X Ray ◽  
The Stability ◽  
Alloy Catalysts ◽  
Dilute Alloy ◽  
Alloy Catalyst

In situ and ex situ X-ray photoelectron spectroscopy and electron-microscopy reveal that the stability of nanoporous NiCu alloy catalysts for non-oxidative ethanol dehydrogenation improves by generating kinetically trapped Ni2+ subsurface states.

An intensity modulated fiber-optic carbon monoxide sensor based on Ag/Co-MOF in-situ coated thin-core fiber

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Lian Wang ◽  
Juncheng Zhou ◽  
Yuhao Chen ◽  
Liu Xiao ◽  
Guojia Huang ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Carbon Monoxide ◽  
Photoelectron Spectroscopy ◽  
Fiber Optic ◽  
Temperature Stability ◽  
Single Mode ◽  
X Ray ◽  
Intensity Modulated ◽  
Core Fiber

Abstract An intensity modulated fiber-optic carbon monoxide (CO) sensor by integrating in-situ solvothermal-growth Ag/Co-MOF sensing film is fabricated and evaluated. The Michelson interference sensing structure is composed of single-mode fiber (SMF), enlarged taper, thin-core fiber (TCF), and Ag film as the reflector. Ag/Co-MOF was coated on the cladding of the TCF as the sensing material, and the enlarged taper is located between TCF and SMF as the coupler. The structure, morphology, compositions and thermal stability of the Ag/Co-MOF sensing film were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), thermogravimetric analysis (TGA), etc. The sensitivity of the sensor is 0.04515 dB/ppm, and the fitting parameter of the CO concentration is 0.99876. In addition, the sensor has the advantages of good selectivity, good signal and temperature stability, and it has potential application in trace CO detection.

Size dependent behavior of Fe3O4crystals during electrochemical (de)lithiation: an in situ X-ray diffraction, ex situ X-ray absorption spectroscopy, transmission electron microscopy and theoretical investigation

2017 ◽  
Vol 19 (31) ◽  
pp. 20867-20880 ◽  
Author(s):  
David C. Bock ◽  
Christopher J. Pelliccione ◽  
Wei Zhang ◽  
Janis Timoshenko ◽  
K. W. Knehr ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Structural Changes ◽  
Ex Situ ◽  
X Ray Diffraction ◽  
X Ray ◽  
Size Dependent ◽  
Transmission Electron ◽  
Dependent Behavior ◽  
X Ray Absorption

Crystal and atomic structural changes of Fe3O4upon electrochemical (de)lithiation were determined.

In Situ Fabrication of Nanoscale Graphene Oxide/Polyaniline Composite and its Electrochemical Properties

2010 ◽  
Vol 148-149 ◽  
pp. 1547-1550 ◽  
Author(s):  
Hua Lan Wang ◽  
Qing Li Hao ◽  
Xi Feng Xia ◽  
Zhi Jia Wang ◽  
Jiao Tian ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Graphene Oxide ◽  
Photoelectron Spectroscopy ◽  
In Situ Polymerization ◽  
Ammonium Persulfate ◽  
Polymerization Process ◽  
Electrochemical Test ◽  
X Ray ◽  
Transmission Electron

A graphene oxide/polyaniline composite was synthesized by an in situ polymerization process. This product was simply prepared in an ethylene glycol medium, using ammonium persulfate as oxidant in ice bath. The composite was characterized by field emission scanning electron microscopy, transmission electron microscopy, X-Ray photoelectron spectroscopy, Raman spectroscopy and electrochemical test. The composite material showed a good electrochemical performance.

(G03 Best Paper Award Winner) Analysis of Sn Behavior During Ni/GeSn Solid-State Reaction by Correlated X-ray Diffraction, Atomic Force Microscopy, and Ex-situ/In-situ Transmission Electron Microscopy

2020 ◽  
Vol MA2020-02 (24) ◽  
pp. 1750-1750
Author(s):  
Andrea Quintero Colmenares ◽  
Patrice Gergaud ◽  
Jean-Michel Hartmann ◽  
Vincent Delaye ◽  
Nicolas Bernier ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Ex Situ ◽  
Paper Award ◽  
X Ray Diffraction ◽  
Award Winner ◽  
X Ray ◽  
Force Microscopy ◽  
Atomic Force ◽  
Transmission Electron

scholarly journals Catalytic Behaviour of Flame-Made CuO-CeO2 Nanocatalysts in Efficient CO Oxidation

Catalysts ◽  
2019 ◽  
Vol 9 (3) ◽  
pp. 256 ◽  
Author(s):  
Feng Zhao ◽  
Shuangde Li ◽  
Xiaofeng Wu ◽  
Renliang Yue ◽  
Weiman Li ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Water Vapor ◽  
Co Oxidation ◽  
Photoelectron Spectroscopy ◽  
Co Adsorption ◽  
Synergistic Interaction ◽  
Flame Spray ◽  
Oxidation Activity ◽  
X Ray

CuO-CeO2 nanocatalysts with varying CuO contents (1, 5, 9, 14 and 17 wt %) were prepared by one-step flame spray pyrolysis (FSP) and applied to CO oxidation. The influences of CuO content on the as-prepared catalysts were systematically characterized by X-ray diffraction (XRD), N2 adsorption-desorption at −196 °C, field emission scanning electron microscopy (FESEM), high-resolution transmission electron microscopy (HRTEM), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), and hydrogen-temperature programmed reduction (H2-TPR). A superior CO oxidation activity was observed for the 14 wt % CuO-CeO2 catalyst, with 90% CO conversion at 98 °C at space velocity (60,000 mL × g−1 × h−1), which was attributed to abundant surface defects (lattice distortion, Ce3+, and oxygen vacancies) and high reducibility supported by strong synergistic interaction. In addition, the catalyst also displayed excellent stability and resistance to water vapor. Significantly, in situ diffuse reflectance infrared Fourier transform spectroscopy (in situ DRIFTS) showed that in the CO catalytic oxidation process, the strong synergistic interaction led readily to dehydroxylation and CO adsorption on Cu+ at low temperature. Furthermore, in the feed of water vapor, although there was an adverse effect on the access of CO adsorption, there was also a positive effect on the formation of fewer carbon intermediates. All these results showed the potential of highly active and water vapor-resistive CuO-CeO2 catalysts prepared by FSP.

Ion Beam Study of Early Stages of Growth of GaN films on Sapphire

2002 ◽  
Vol 743 ◽  
Author(s):  
Eugen M. Trifan ◽  
David C. Ingram
Keyword(s):  
Photoelectron Spectroscopy ◽  
Ion Beam ◽  
Ex Situ ◽  
Crystallographic Axis ◽  
In Situ Characterization ◽  
X Ray ◽  
Ion Channeling ◽  
Stages Of Growth ◽  
Early Stages

ABSTRACTAn innovative approach for in-situ characterization has been used in this work to investigate the composition, growth mode, morphology and crystalline ordering of the early stages of growth of GaN films grown on sapphire by MOCVD for substrate temperatures in the range of 450°C to 1050°C. We have performed in-situ characterization by Rutherford Backscattering Spectroscopy (RBS), Ion Channeling, X-ray Photoelectron Spectroscopy (XPS), and Low Energy Electron Diffraction. Ex-situ the films have been characterized by Scanning Electron Microscopy (SEM), X-ray Diffraction (XRD) and thickness profilometry. The films have been grown in an in-house designed and build MOCVD reactor that is attached by UHV lines to the analysis facilities. RBS analysis indicated that the films have the correct stoichiometry, have variable thickness and for low substrate temperature completely cover the substrate while for temperatures 850°C and higher islands are formed that may cover as few as 5 percent of the substrate. From Ion Channeling and LEED we have determined the crystallographic phase to be wurtzite. The crystalline quality increases with higher deposition temperature and with thickness. The films are epitaxialy grown with the <0001> crystallographic axis and planes of the GaN films aligned with the sapphire within 0.2 degrees.

Study of Ta as a Diffusion Barrier in Cu/SiO2 Structure

2000 ◽  
Vol 612 ◽  
Author(s):  
J. S. Pan ◽  
A. T. S. Wee ◽  
C. H. A. Huan ◽  
J. W. Chai ◽  
J. H. Zhang
Keyword(s):  
Photoelectron Spectroscopy ◽  
Electron Spectroscopy ◽  
Auger Electron ◽  
Room Temperature ◽  
Depth Profiling ◽  
Oxide Formation ◽  
X Ray ◽  
Chemical States ◽  
The Stability

AbstractTantalum (Ta) thin films of 35 nm thickness were investigated as diffusion barriers as well as adhesion-promoting layers between Cu and SiO2 using X-ray diffractometry (XRD), Scanning electron microscopy (SEM), Auger electron spectroscopy (AES) and X-ray photoelectron spectroscopy (XPS). After annealing at 600°C for 1h in vacuum, no evidence of interdiffusion was observed. However, XPS depth profiling indicates that elemental Si appears at the Ta/SiO2 interface after annealing. In-situ XPS studies show that the Ta/SiO2 interface was stable until 500°C, but about 32% of the interfacial SiO2 was reduced to elemental Si at 600°C. Upon cooling to room temperature, some elemental Si recombined to form SiO2 again, leaving only 6.5% elemental Si. Comparative studies on the interface chemical states of Cu/SiO2 and Ta/SiO2 indicate that the stability of the Cu/Ta/SiO2/Si system may be ascribed to the strong bonding of Ta and SiO2, due to the reduction of SiO2 through Ta oxide formation.

Surface nitridation of Ta powder by molten-salt electrolysis of Ta2O5 under N2 atmosphere

2020 ◽  
Vol 13 (07) ◽  
pp. 2050032
Author(s):  
Qing Huang ◽  
Guojin Zheng ◽  
Tian Wu
Keyword(s):  
Electron Microscopy ◽  
Photoelectron Spectroscopy ◽  
Cell Voltage ◽  
X Ray Diffraction ◽  
Molten Salt Electrolysis ◽  
X Ray ◽  
Structured Catalysts ◽  
Transmission Electron ◽  
N2 Atmosphere

The electro-deoxidation of Ta2O5 in molten CaCl2 under N2 atmosphere is a facile way for the in situ surface nitridation of Ta particles. The cell voltage and electrolysis time of Ta2O5 are rationalized to realize the in situ surface nitridation of Ta. All the characterization results including X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and elements mapping as well as X-ray photoelectron spectroscopy (XPS) confirm the formation of Ta2N layers on the surface of Ta particles, with the thickness of 3–4[Formula: see text]nm. This method provides a strategy for the facile in situ surface nitridation with N2 as the nitrogen source for the fabrication of core-shell structured catalysts.

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