Pt/C and Pt/SnOx/C catalysts were synthesized using the polyol method. Their structure, morphology and chemical composition were studied using a scanning electron microscope equipped with an energy dispersive X-ray spectrometer, transition electron microscope and X-ray photoelectron spectroscope. Electrochemical measurements were based on the results of rotating disk electrode (RDE) experiments applied to ethanol electrooxidation. The quick evaluation of catalyst activity, electrochemical behavior, and an average number of transferred electrons were made using the RDE technique. The usage of SnOx (through the carbon support modification) in a binary system together with Pt causes a significant increase of the catalyst activity in ethanol oxidation reaction and the utilization of ethanol.

No abstract

No abstract

Polarized optical conductivity spectra in the IR and visible range and variable-temperature photoluminescence spectra of the C 60 F 18 single crystals in the 4-300 K temperature range are reported. Density-functional theory ͑DFT͒ calculations of vibrational spectra and time-dependent DFT calculations of the excitation energies of the C 60 F 18 molecule are performed to interpret experimentally observed phenomena. Orientation of the C 3v -symmetric C 60 F 18 molecules in the single crystal is revealed by comparison of the experimental polarized IR spectra and vibrational DFT calculations. A 2 symmetry is assigned to the lowest energy singlet excited state of C 60 F 18 , and hence pure electronic S 0 → S 1 excitation is found to be dipole forbidden. Fine vibronic structure found at low temperature is interpreted in terms of Herzberg-Teller and Franck-Condon mechanisms. Considerable similarity with vibronic spectra of C 60 is found and explained by presumable localization of the lowest energy electronic excitation of C 60 F 18 on the fullerenelike part of the molecule.

Russian studies of hydrogen isotope retention in plasma facing materials of the International Thermonuclear Experimental Reactor included the analysis of carbon-deuterium flakes, formed in the vacuum chamber of the T-10 tokamak, as well as modelling of normal reactor operation conditions and plasma disruptions. The decrease in the [D]/[C] atomic ratio and the decrease in the mass of flakes when these flakes were annealed in air and water steam against temperature were determined. Using Fourier transform infrared reflection spectroscopy, we found that deuterium is accumulated in the flakes only in two states: in the C−D 2 sp 3 deformation modes at 633 and 1090 cm −1 and in the C−D 2,3 sp 3 stretching modes at 2100-2200 cm −1 . In co-deposited Be + D films the [D]/[Be] atomic ratio decreases from 0.15 at 375 K to 0.05 at 575 K. Carbon impurities in the Be + D films slightly increases deuterium retention. The effect of plasma disruptions on deuterium retention in tungsten is described.