Photoelectron Spectroscopy of Benzene in the Liquid Phase and Dissolved in Liquid Ammonia

Author(s):  
H. Christian Schewe ◽  
Krystof Brezina ◽  
Vojtech Kostal ◽  
Philip E. Mason ◽  
Tillmann Buttersack ◽  
...  
2019 ◽  
Vol 31 (1) ◽  
pp. 68-74 ◽  
Author(s):  
Fen Peng ◽  
Wensheng Liu ◽  
Yufeng Huang ◽  
Siwei Tang ◽  
Chaoping Liang ◽  
...  

Purpose The purpose of this study is to develop a monolayer surface coating of stearic acid on Sn-Ag-Cu solder powder to limit oxidation. Design/methodology/approach Stearic acid was adsorbed onto Sn-Ag-Cu solder powder through liquid-phase adsorption. The isotherm of adsorption was measured and then the microstructure of coated powder was characterized by scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy and Fourier-transform infrared spectroscopy. Findings The adsorption isotherm of stearic acid on the powder was “H” type, which revealed the layer-by-layer adsorption on non-porous surface. When the concentration of solution was in the range of 0.001-0.006 mol/L, with an adsorption amount of 0.12 ± 0.1 mg/g, monolayer stearic acid covered the solder powder completely. Uniform and integrated self-assembled monolayer coating was formed through hydrogen bonds between the oxygen ions in surface lattice of Sn3.0Ag0.5Cu solder powder and the —O—H hydroxyl group of stearic acid. The maximum angle of stability of coated powder also reduced by 2.87° compared with that of non-coated powder. The increase rate of oxygen content of coated powder was much slower than that of non-coated powder when they were exposed to humid air. Originality/value As a result, oxidation of fine solder powder was effectively limited. Essentially, this method can also be applied to the coating of other types of solder powder and has reference significance to other coating by liquid-phase method.


2020 ◽  
Vol 73 (11) ◽  
pp. 1088
Author(s):  
Altafhusen Naikwade ◽  
Megha Jagadale ◽  
Dolly Kale ◽  
Gajanan Rashinkar

A new magnetic nanoparticle supported ionic liquid phase (SILP) catalyst containing perruthenate anions was prepared by a multistep procedure. The various analytical techniques such as FT-IR spectroscopy, X-ray photoelectron spectroscopy, transmission electron microscopy, thermogravimetric analysis, energy dispersive X-ray analysis, and vibrating sample magnetometer analysis ascertained the successful formation of catalyst. The performance of a magnetically retrievable SILP catalyst was evaluated in the selective oxidation of alcohols. The split test and leaching studies of the SILP catalyst confirmed its heterogeneous nature. In addition, the reusability potential of SILP catalyst was also investigated which revealed its robust activity up to six consecutive cycles.


1984 ◽  
Vol 39 (11) ◽  
pp. 1536-1540 ◽  
Author(s):  
Reinhard Schulz ◽  
Armin Schweig

Abstract The gas-phase pyrolysis of cyclohexeno-1,2,3-selenadiazole and cycloocteno-1,2,3-selenadiazole has been investigated by variable temperature photoelectron spectroscopy and matrix IR spectroscopy. The ring contracted, highly reactive products cyclopentylidenselenoketene (cyclopentylidenmethanselone) and cycloheptylidenselenoketene (cycloheptylidenmethanselone) - which had not been found in liquid phase thermolysis experiments - have been detected. Additionally HeI photoelectron and IR spectra of analogous ketenes and thioketenes are presented for comparative reasons.


2018 ◽  
Vol 96 (4) ◽  
pp. 394-403 ◽  
Author(s):  
Wei Long ◽  
Pingle Liu ◽  
Yang Lv ◽  
Wei Xiong ◽  
Fang Hao ◽  
...  

Silica-supported copper catalysts were prepared by different methods, and Cu/SiO2 prepared by the urea-assisted gel method was modified with co-catalyst platinum to obtain Cu-Pt/SiO2 bimetallic catalysts. The prepared catalysts were characterized by nitrogen adsorption–desorption, XRD, TEM, hydrogen chemisorption, ammonia gas chemisorption, and X-ray photoelectron spectroscopy. The characterization results show that the modification of platinum is helpful to the reduction and dispersion of copper species, which increase the hydrogen uptake quantity and metal surface area. The 30%Cu–3.0%Pt/SiO2-6 presents the best catalytic performance in liquid-phase diethyl oxalate hydrogenation; it gives 77.32% conversion of diethyl oxalate and 94.37% selectivity to the main products under 473 K and 3.0 MPa for 4 h. A possible reaction route was also proposed.


Nanomaterials ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 2344
Author(s):  
Byung-Joo Kim ◽  
Kay-Hyeok An ◽  
Wang-Geun Shim ◽  
Young-Kwon Park ◽  
Jaegu Park ◽  
...  

Ag particles were precipitated on an activated carbon fiber (ACF) surface using a liquid phase plasma (LPP) method to prepare a Ag/ACF composite. The efficiency was examined by applying it as an adsorbent in the acetaldehyde adsorption experiment. Field-emission scanning electron microscopy and energy-dispersive X-ray spectrometry confirmed that Ag particles were distributed uniformly on an ACF surface. X-ray diffraction and X-ray photoelectron spectroscopy confirmed that metallic silver (Ag0) and silver oxide (Ag2O) precipitated simultaneously on the ACF surface. Although the precipitated Ag particles blocked the pores of the ACF, the specific surface area of the Ag/ACF composite material decreased, but the adsorption capacity of acetaldehyde was improved. The AA adsorption of ACF and Ag/ACF composites performed in this study was suitable for the Dose–Response model.


Catalysts ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 623
Author(s):  
Yuwei Feng ◽  
Aiwu Zeng

The catalytic performance of Mn3O4 supported on carbon nanotubes (CNTs) in the liquid-phase oxidation of toluene to benzyl alcohol and benzaldehyde was studied. The supported catalysts were characterized by X-ray diffraction (XRD), Raman spectroscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), N2 adsorption–desorption isotherms and ICP-MS. The results demonstrate that Mn3O4 nanoparticles loaded on CNTs performed better compared with pristine Mn3O4 or CNTs. The main reason for the increased catalytic activity is the dispersion and loading of Mn3O4 in CNTs. By optimizing the reaction temperature, reaction time, catalyst quality, oxygen flow rate and initiator dosage, the optimum reaction conditions were obtained. Using tert-butyl hydroperoxide (TBHP) as the initiator and oxygen as the oxidant, the toluene conversion rate was as high as 24.63%, and benzyl alcohol and benzaldehyde selectivity was 90.49%. The good stability of the catalyst was confirmed by repeating the experiment for four cycles and observing no significant changes in its performance.


1949 ◽  
Vol 27b (11) ◽  
pp. 861-873 ◽  
Author(s):  
J. W. Hodgins

Measurements of vapor pressure, liquid density, and electrical conductance were made on solutions of cesium in liquid ammonia. The solutions differ from those of the other alkali metals in that there is no indication of liquid–liquid phase separation for concentrations 0.04 N to 7 N. Experiments on rings of solution frozen in liquid nitrogen make it appear unlikely that the system is superconducting at 77° K.


1988 ◽  
Vol 110 (4a) ◽  
pp. 992-995 ◽  
Author(s):  
A. A. Clifford ◽  
R. Tufeu

The thermal conductivity of gaseous and liquid ammonia has been measured in the range 300–300 K and at pressures up to 50 MPa. The measurements were a necessary preliminary to a fitting of the thermal conductivity surface in the density–temperature plane, which is part of the current program of the Transport Properties Subcommittee of the I.U.P.A.C. Results were obtained that are believed to be accurate to 2 percent. It is difficult to make a good comparison of these results with previous data until a full correlation of the thermal conductivity of ammonia is carried out. A preliminary assessment for the liquid phase indicates that agreement is reasonable over much of the range with differences up to around 5 percent under certain conditions. For the gas phase an approximate extrapolation to atmospheric pressure can be made and the results compared with some recent recommended values. Differences of ±3 percent are observed.


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