Authors:Y. Minai, T. Fukushima, M. Ichikawa, and T. Tominaga
Silica supported Rh–Fe catalysts were characterized by means of in situ57Fe Mössbauer spectroscopy. The Mössbauer spectra indicated that iron on the silica support existed either as Fe/O/ in the Rh–Fe alloy or as Fe3+ in Rh–Fe metal cluster compounds. The (Fe3+/Fe/O/) ratio and Mössbauer parameters were found to depend on the (Fe/Rh) atomic ratio in the catalysts. Such dependence corresponded to the change of catalytic properties of the supported Rh–Fe catalyst with the varying (Fe/Rh) ratio.
Authors:Y. Minai, T. Fukushima, S. Ogasawara, M. Ichikawa, and T. Tominaga
Fe-57 Mössbauer spectra of silica-supported Pd–Fe bimetallic catalysts show remarkable changes with varying Fe/Pd atomic ratios. From the spectra, the main Fe-component is estimated as highly dispersed Fe in the Fe/Pd range of 0.05–0.3 and -Fe ensemble and Fe–Pd intermetallics in the Fe/Pd range above 0.3. It is suggested that the chemical state of iron is associated with the catalytic performance in effective CO–H2 conversion to methanol.
Authors:M. Fukushima, H. Tamate, S. Sato, S. Terui, and T. Mitsugashira
The normal concentration levels of trace metals in several kinds of tissues of even-toed ungulates have been determined by
instrumental neutron activation analysis, photon activation analysis, and flame atomic absorption spectrometry. In the present
work the concentrations of 13 elements (Ag, Br, Ca, Co, Cu, Fe, Mg, Mn, Mo, Na, Rb, Se, and Zn) were analyzed.
Authors:H. Fukushima, T. Kimura, H. Hamaguchi, T. Nozaki, Y. Itoh, and Y. Ohkubo
Bombardment conditions, chemical separation, and counting method were examined for routine determination of carbon, nitrogen, and oxygen in various matrices by charged-particle activation analysis with respect to reliability, reproducibility, simplicity, and rapidity. A system was then set up for trustworthy measurement of these elements.