X-ray photoelectron spectroscopy analysis for oxidation states of titanium chloride on the surface of Ziegler-Natta catalysts

1997 ◽  
Vol 124 (1) ◽  
pp. L1-L3 ◽  
Author(s):  
Koichi Hasebe ◽  
Hideharu Mori ◽  
Minoru Terano
Keyword(s):  
Photoelectron Spectroscopy ◽  
Oxidation States ◽  
Titanium Chloride ◽  
Spectroscopy Analysis ◽  
X Ray ◽  
Ziegler Natta Catalysts

SiO2 films as heat resistant layers for protection of expandable polystyrene foam from flame torch–induced heat

2017 ◽  
Vol 31 (5) ◽  
pp. 657-667 ◽  
Author(s):  
S Varnagiris ◽  
S Tuckute ◽  
M Lelis ◽  
D Milcius
Keyword(s):  
Heat Resistance ◽  
Photoelectron Spectroscopy ◽  
Silicon Oxide ◽  
Plasma Generator ◽  
Expanded Polystyrene ◽  
Spectroscopy Analysis ◽  
X Ray ◽  
Heat Resistant ◽  
Pulsed Dc ◽  
Gas Atmosphere

Currently, polymeric insulation materials are widely used for energy saving in buildings. Despite of all benefits, these materials are generally sensitive to heat and highly flammable. This work discusses possibility to improve heat resistance of expanded polystyrene (EPS) foam using thin silicon dioxide (SiO2) films deposited by magnetron sputtering technique. In order to increase surface energy and adherence of SiO2 thin films to substrate EPS was plasma pretreated before films’ depositions using pulsed DC plasma generator for 40 s in argon gas. SiO2 formation was done in reactive argon and oxygen gas atmosphere. Laboratory made equipment was used for flame torch–induced heat resistance experiments. Results showed that silicon oxide films remains stable during heat resistance experiments up to 5 s and fully protects polystyrene (PS) substrate. Films are relatively stable for 30 s and 60 s and partially protect PS from melting and ignition. Scanning electron microscopy, energy-dispersive X-ray spectroscopy, and X-ray photoelectron spectroscopy analysis confirmed that SiO2 layer, which is distributed uniformly on the EPS surface, could work as a good heat resistant material.

Effect of Sodium Metabisulfite on Selective Flotation of Chalcopyrite and Molybdenite

Minerals ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1377
Author(s):  
Yuki Semoto ◽  
Gde Pandhe Wisnu Suyantara ◽  
Hajime Miki ◽  
Keiko Sasaki ◽  
Tsuyoshi Hirajima ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Separation Efficiency ◽  
Diesel Oil ◽  
Sodium Metabisulfite ◽  
Depressing Effect ◽  
Spectroscopy Analysis ◽  
X Ray ◽  
Selective Flotation

Sodium metabisulfite (MBS) was used in this study for selective flotation of chalcopyrite and molybdenite. Microflotation tests of single and mixed minerals were performed to assess the floatability of chalcopyrite and molybdenite. The results of microflotation of single minerals showed that MBS treatment significantly depressed the floatability of chalcopyrite and slightly reduced the floatability of molybdenite. The results of microflotation of mixed minerals demonstrated that the MBS treatment could be used as a selective chalcopyrite depressant in the selective flotation of chalcopyrite and molybdenite. Furthermore, the addition of diesel oil or kerosene could significantly improve the separation efficiency of selective flotation of chalcopyrite and molybdenite using MBS treatment. A mechanism based on X-ray photoelectron spectroscopy analysis results is proposed in this study to explain the selective depressing effect of MBS on the flotation of chalcopyrite and molybdenite.

scholarly journals Photocatalytic CO2 Reduction and Electrocatalytic H2 Evolution over Pt(0,II,IV)-Loaded Oxidized Ti Sheets

Nanomaterials ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 1909
Author(s):  
Ju Hyun Yang ◽  
So Jeong Park ◽  
Choong Kyun Rhee ◽  
Youngku Sohn
Keyword(s):  
Hydrogen Evolution ◽  
Photoelectron Spectroscopy ◽  
Co2 Reduction ◽  
Oxidation States ◽  
X Ray ◽  
Catalytic Activities ◽  
Before And After ◽  
Reduction Methods ◽  
Chemical States ◽  
Sputter Deposited

Energy recycling and production using abundant atmospheric CO2 and H2O have increasingly attracted attention for solving energy and environmental problems. Herein, Pt-loaded Ti sheets were prepared by sputter-deposition and Pt4+-reduction methods, and their catalytic activities on both photocatalytic CO2 reduction and electrochemical hydrogen evolution were fully demonstrated. The surface chemical states were completely examined by X-ray photoelectron spectroscopy before and after CO2 reduction. Gas chromatography confirmed that CO, CH4, and CH3OH were commonly produced as CO2 reduction products with total yields up to 87.3, 26.9, and 88.0 μmol/mol, respectively for 700 °C-annealed Ti under UVC irradiation for 13 h. Pt-loading commonly negated the CO2 reduction yields, but CH4 selectivity was increased. Electrochemical hydrogen evolution reaction (HER) activity showed the highest activity for sputter-deposited Pt on 400 °C-annealed Ti with a HER current density of 10.5 mA/cm2 at −0.5 V (vs. Ag/AgCl). The activities of CO2 reduction and HER were found to be significantly dependent on both the nature of Ti support and the oxidation states (0,II,IV) of overlayer Pt. The present result could provide valuable information for designing efficient Pt/Ti-based CO2 recycle photocatalysts and electrochemical hydrogen production catalysts.

scholarly journals X-ray photoelectron spectroscopy analysis as a tool to assess factors influencing magnetic anisotropy type in Co/MgO system with gold interlayer

2018 ◽  
Vol 145 ◽  
pp. 50-53 ◽  
Author(s):  
Iraida N. Demchenko ◽  
Yevgen Syryanyy ◽  
Yevgen Melikhov ◽  
Laurent Nittler ◽  
Leszek Gladczuk ◽  
...  
Keyword(s):  
Magnetic Anisotropy ◽  
Photoelectron Spectroscopy ◽  
Spectroscopy Analysis ◽  
X Ray ◽  
Factors Influencing

An X-Ray Photoelectron Spectroscopic Study of Copper Chromite Catalysts

1979 ◽  
Vol 33 (4) ◽  
pp. 380-384 ◽  
Author(s):  
J. A. Schreifels ◽  
A. Rodero ◽  
W. E. Swartz
Keyword(s):  
Spectroscopic Study ◽  
Calcination Temperature ◽  
Photoelectron Spectroscopy ◽  
Copper Chromite ◽  
Oxidation States ◽  
Surface Species ◽  
Catalytic Surface ◽  
X Ray

A series of copper chromite catalysts have been studied by x-ray photoelectron spectroscopy. The data indicate that in the as-received form the copper is present as a mixture of Cu(OH)2 and CuO. After calcination at 500 °C only CuO is present. The chromium is present as Cr+3 and Cr+4 when no promoter is added. When a BaO promoter is added, the Cr+6 is stabilized. Calcination at 500°C for varying periods of time alter the relative amounts of Cr+3 and Cr+6 on the catalytic surface. In addition, the relative amounts of the various oxidation states are a function of calcination temperature. At a calcination temperature of 240°C a Cr+5 surface species is reproducibly observed in one of the catalysts.

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