Encapsulation of Atomically Dispersed Pt Clusters in Porous TiO2 for Semi-Hydrogenation of Phenylacetylene

2022 ◽  
Author(s):  
Huibin Wu ◽  
Xinchun Yang ◽  
Shichao Zhao ◽  
Liming Zhai ◽  
Guofu Wang ◽  
...  
Keyword(s):  
Strong Interaction ◽  
High Efficiency ◽  
Metal Clusters ◽  
Porous Tio2

The synthesis of atomically dispersed metal clusters with strong interaction with the support is attractive for the design of high-efficiency catalysts. Here, we report a multilayered catalyst (1.91%Pt@TiO2), in which...

Fabrication of porous TiO2-RGO hybrid aerogel for high-efficiency, visible-light photodegradation of dyes

2020 ◽  
Vol 819 ◽  
pp. 153033 ◽  
Author(s):  
Xiaoqiang Sun ◽  
Shangdong Ji ◽  
Minqiang Wang ◽  
Jinjuan Dou ◽  
Zhi Yang ◽  
...  
Keyword(s):  
Visible Light ◽  
High Efficiency ◽  
Porous Tio2 ◽  
Hybrid Aerogel

Pulsed Vaporization Sources for High Efficiency Prouduction of Metal Clusters

1995 ◽  
Vol 195 ◽  
pp. 43-48 ◽  
Author(s):  
P. Milani ◽  
P. Piseri ◽  
E. Barborini ◽  
S. Iannotta
Keyword(s):  
High Efficiency ◽  
Metal Clusters

scholarly journals Na-promoted Ni/ZrO2 dry reforming catalyst with high efficiency: details of Na2O–ZrO2–Ni interaction controlling activity and coke formation

2017 ◽  
Vol 7 (22) ◽  
pp. 5386-5401 ◽  
Author(s):  
M. Németh ◽  
D. Srankó ◽  
J. Károlyi ◽  
F. Somodi ◽  
Z. Schay ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Strong Interaction ◽  
High Efficiency ◽  
Coke Formation ◽  
Dry Reforming ◽  
Reforming Catalyst ◽  
Good Catalytic Activity

Balanced, strong interaction of Ni–Na2O–ZrO2 catalyst components under CO2 reforming of methane is a criterion of good catalytic activity and stability.

Synergism of molybdenum nitride and palladium for high-efficiency formic acid electrooxidation

2018 ◽  
Vol 6 (17) ◽  
pp. 7623-7630 ◽  
Author(s):  
Haijing Yan ◽  
Yanqing Jiao ◽  
Aiping Wu ◽  
Chungui Tian ◽  
Lei Wang ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Formic Acid ◽  
Strong Interaction ◽  
High Efficiency ◽  
Formic Acid Oxidation ◽  
Acid Oxidation ◽  
Molybdenum Nitride ◽  
Intimate Contact ◽  
Co Tolerance ◽  
Reduced Graphene

In this paper, a coupled Mo2N–Pd structure with intimate contact and strong interaction located on reduced graphene oxide (Pd–Mo2N/rGO) was successfully designed for high-efficiency formic acid oxidation. The Pd–Mo2N/rGO catalyst shows superior activity to Pd/rGO and Pd/VC, respectively. In addition, Pd–Mo2N/rGO exhibits enhanced CO tolerance and good stability.

Microcalorimeters for X-Ray Spectroscopy

1988 ◽  
Vol 102 ◽  
pp. 41
Author(s):  
E. Silver ◽  
C. Hailey ◽  
S. Labov ◽  
N. Madden ◽  
D. Landis ◽  
...  
Keyword(s):  
High Resolution ◽  
High Efficiency ◽  
Thermal Response ◽  
Low Noise ◽  
High Resolution Spectroscopy ◽  
Superconducting Transition ◽  
Sapphire Substrates ◽  
Laboratory Plasmas ◽  
Adiabatic Demagnetization ◽  
Theoretical Predictions

The merits of microcalorimetry below 1°K for high resolution spectroscopy has become widely recognized on theoretical grounds. By combining the high efficiency, broadband spectral sensitivity of traditional photoelectric detectors with the high resolution capabilities characteristic of dispersive spectrometers, the microcalorimeter could potentially revolutionize spectroscopic measurements of astrophysical and laboratory plasmas. In actuality, however, the performance of prototype instruments has fallen short of theoretical predictions and practical detectors are still unavailable for use as laboratory and space-based instruments. These issues are currently being addressed by the new collaborative initiative between LLNL, LBL, U.C.I., U.C.B., and U.C.D.. Microcalorimeters of various types are being developed and tested at temperatures of 1.4, 0.3, and 0.1°K. These include monolithic devices made from NTD Germanium and composite configurations using sapphire substrates with temperature sensors fabricated from NTD Germanium, evaporative films of Germanium-Gold alloy, or material with superconducting transition edges. A new approache to low noise pulse counting electronics has been developed that allows the ultimate speed of the device to be determined solely by the detector thermal response and geometry. Our laboratory studies of the thermal and resistive properties of these and other candidate materials should enable us to characterize the pulse shape and subsequently predict the ultimate performance. We are building a compact adiabatic demagnetization refrigerator for conveniently reaching 0.1°K in the laboratory and for use in future satellite-borne missions. A description of this instrument together with results from our most recent experiments will be presented.

Production and STEM examination of controlled-size silver clusters

1983 ◽  
Vol 41 ◽  
pp. 338-339
Author(s):  
M. A. Listvan ◽  
R. P. Andres
Keyword(s):  
Cluster Size ◽  
Metal Clusters ◽  
Experimental Parameter ◽  
Carbon Films ◽  
Metal Species ◽  
Silver Clusters ◽  
Free Jet ◽  
Size Dependent ◽  
Cluster Properties ◽  
Controllable Size

Knowledge of the function and structure of small metal clusters is one goal of research in catalysis. One important experimental parameter is cluster size. Ideally, one would like to produce metal clusters of regulated size in order to characterize size-dependent cluster properties.A source has been developed which is capable of producing microscopic metal clusters of controllable size (in the range 5-500 atoms) This source, the Multiple Expansion Cluster Source, with a Free Jet Deceleration Filter (MECS/FJDF) operates as follows. The bulk metal is heated in an oven to give controlled concentrations of monomer and dimer which were expanded sonically. These metal species were quenched and condensed in He and filtered to produce areosol particles of a controlled size as verified by mass spectrometer measurements. The clusters were caught on pre-mounted, clean carbon films. The grids were then transferred in air for microscopic examination. MECS/FJDF was used to produce two different sizes of silver clusters for this study: nominally Ag6 and Ag50.

Imaging and diffraction modes in Scanning Transmission Electron Microscopy

1986 ◽  
Vol 44 ◽  
pp. 684-687
Author(s):  
J. M. Cowley ◽  
R. Glaisher ◽  
J. A. Lin ◽  
H.-J. Ou
Keyword(s):  
Scanning Transmission Electron Microscopy ◽  
High Efficiency ◽  
Fiber Optic ◽  
Image Intensifier ◽  
Detector System ◽  
Detector Plane ◽  
Secondary Electrons ◽  
Transmission Electron ◽  
Scanning Transmission ◽  
Special Detector

Some of the most important applications of STEM depend on the variety of imaging and diffraction made possible by the versatility of the detector system and the serial nature, of the image acquisition. A special detector system, previously described, has been added to our STEM instrument to allow us to take full advantage of this versatility. In this, the diffraction pattern in the detector plane may be formed on either of two phosphor screens, one with P47 (very fast) phosphor and the other with P20 (high efficiency) phosphor. The light from the phosphor is conveyed through a fiber-optic rod to an image intensifier and TV system and may be photographed, recorded on videotape, or stored digitally on a frame store. The P47 screen has a hole through it to allow electrons to enter a Gatan EELS spectrometer. Recently a modified SEM detector has been added so that high resolution (10Å) imaging with secondary electrons may be used in conjunction with other modes.

Influence of MBE Growth Conditions on Dislocation Densities of GaAs/Ge Epilayers Grown on Silicon Substrates

1985 ◽  
Vol 43 ◽  
pp. 364-365
Author(s):  
K.M. Hones ◽  
P. Sheldon ◽  
B.G. Yacobi ◽  
A. Mason
Keyword(s):  
High Efficiency ◽  
Lattice Mismatch ◽  
Low Cost ◽  
Growth Conditions ◽  
Nonradiative Recombination ◽  
Device Structure ◽  
Si Substrates ◽  
Transmission Electron ◽  
Dislocation Densities ◽  
Dislocation Type

There is increasing interest in growing epitaxial GaAs on Si substrates. Such a device structure would allow low-cost substrates to be used for high-efficiency cascade- junction solar cells. However, high-defect densities may result from the large lattice mismatch (∼4%) between the GaAs epilayer and the silicon substrate. These defects can act as nonradiative recombination centers that can degrade the optical and electrical properties of the epitaxially grown GaAs. For this reason, it is important to optimize epilayer growth conditions in order to minimize resulting dislocation densities. The purpose of this paper is to provide an indication of the quality of the epitaxially grown GaAs layers by using transmission electron microscopy (TEM) to examine dislocation type and density as a function of various growth conditions. In this study an intermediate Ge layer was used to avoid nucleation difficulties observed for GaAs growth directly on Si substrates. GaAs/Ge epilayers were grown by molecular beam epitaxy (MBE) on Si substrates in a manner similar to that described previously.

The use of high-resolution FESEM to study solid-state phase transformations and reactions

1994 ◽  
Vol 52 ◽  
pp. 1028-1029
Author(s):  
P. G. Kotula ◽  
D. D. Erickson ◽  
C. B. Carter
Keyword(s):  
Solid State ◽  
High Resolution ◽  
Phase Transformations ◽  
High Efficiency ◽  
Sol Gel ◽  
Quantitative Information ◽  
Solid State Reactions ◽  
Critical Dimensions ◽  
Backscattered Electrons ◽  
Backscattered Electron

High-resolution field-emission-gun scanning electron microscopy (FESEM) has recently emerged as an extremely powerful method for characterizing the micro- or nanostructure of materials. The development of high efficiency backscattered-electron detectors has increased the resolution attainable with backscattered-electrons to almost that attainable with secondary-electrons. This increased resolution allows backscattered-electron imaging to be utilized to study materials once possible only by TEM. In addition to providing quantitative information, such as critical dimensions, SEM is more statistically representative. That is, the amount of material that can be sampled with SEM for a given measurement is many orders of magnitude greater than that with TEM.In the present work, a Hitachi S-900 FESEM (operating at 5kV) equipped with a high-resolution backscattered electron detector, has been used to study the α-Fe2O3 enhanced or seeded solid-state phase transformations of sol-gel alumina and solid-state reactions in the NiO/α-Al2O3 system. In both cases, a thin-film cross-section approach has been developed to facilitate the investigation. Specifically, the FESEM allows transformed- or reaction-layer thicknesses along interfaces that are millimeters in length to be measured with a resolution of better than 10nm.

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