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The initial stages of growth of the nanostructured cerium oxide deposited on the polycrystalline tungsten surface by pulsed laser deposition are studied using XPS technique. The population of Ce (III) and Ce (IV) oxidation states in the deposited CeO2−x layers is determined applying factor analysis method. Tungsten atoms react with oxygen from the cerium oxide nanoparticles already at the room temperature, and a layer of tungsten trioxide is formed at the interface. Gradual heating of the samples up to 900 K leads to the increase of the thickness of WO3 oxide layer and a partial reduction of Ce (IV) to Ce (III). The spectra of O (1s) photoelectrons are composed from a signal originating from metal oxides and a signal of surface superoxide and hydroxyl groups. Factor analysis was performed on the spectra of Ce (3d) photoelectrons to determine the position, shape, and intensity of the spectral components belonging to Ce (III) and Ce (IV) oxidation states. We propose a new simple method to generate components of the spectroscopic meaning. The basic idea of our method consists in the use of the slightly positive values instead of zeros to the needle test vector. Two components are required to reproduce the original data within the experimental errors. Copyright © 2015 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Surfaces of chalcopyrite CuFeS2, sphalerite ZnS, pyrite FeS2 and galena PbS modified by mechanical activation have been studied by means of infrared (IR) spectroscopy, diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) and X-ray photoelectron spectroscopy (XPS). The different oxidation species were identified on mechanically disordered surfaces of the minerals. The mechanochemical surface oxidation increases with the time of mechanical activation. The sulphides under study are partially covered with oxidised sulphates and carbonate species. They are distinguished by an affinity to the formation of surface compounds. According to the affinity of sulphides for mechanochemical S2−→S6+ surface oxidation the decreasing rate was observed in the following order: FeS2>PbS>CuFeS2>ZnS. The ratio between bivalent and hexavalent form of sulphur depends on the degree of mechanochemical surface oxidation of the sample under study. [Copyright &y& Elsevier]

Abstract: Synthetic zeolite ZSM5 and its copper forms containing N,N-dimethylethylenediamine (dmen) have been investigated by CHN, energy dispersive spectroscopy (EDS) analysis, X-ray powder diffractometry, X-ray photoelectron spectroscopy and continuous waves hydrogen nuclear magnetic resonance (CW 1H NMR) spectroscopy. Thermal properties have been studied by methods of thermal analysis—TG, DTA and DTG in the temperature range 20–1000°C in air atmosphere. Mass spectroscopy method was used for the study of the released gas products of thermal decomposition. The results of thermal analyses of two zeolitic samples Cu-ZSM5 and Cu(dmen) x ZSM5 (x depends on the mode of preparation) demonstrated their different thermal properties. The main part of the decomposition process of the samples Cu(dmen) x ZSM5 occurs at considerably higher temperatures than the boiling point of dimethylethylenediamine, proving strong bond and irreversibility of dmen–zeolite interaction. According to the results of mass spectroscopy the decomposition process in inert atmosphere is characterized by the development of a large spectrum of products with atomic mass from 18 to 447 atomic mass units as a consequence of the catalytic effect of the silicate surface. [Copyright &y& Elsevier]