Fachgebiet Mineralogie

2 Items

Recent Submissions
Dissolution behaviour of beryl

Kurumathoor Parameshwaran, Raji (2016)

Beryl, a cyclosilicate, with an ideal chemical composition Be3Al2Si6O18, is the most important accessory Be mineral and an ore of the strategic element Be. It is mainly found in pegmatites, in some highly evolved granites and in some metamorphic rocks. In many cases, the beryl forming process extends over a wide range of P-T-X conditions. This process represents the major range of pegmatitic fo...

Structure of the catalytic sites in Fe/N/C-catalysts for O-2-reduction in PEM fuel cells

Kramm, Ulrike I. ; Herranz, Juan ; Larouche, Nicholas ; Arruda, Thomas M. ; Lefèvre, Michel ; Jaouen, Frédéric ; Bogdanoff, Peter ; Fiechter, Sebastian ; Abs-Wurmbach, Irmgard ; Mukerjee, Sanjeev ; Dodelet, Jean-Pol (2012)

Fe-based catalytic sites for the reduction of oxygen in acidic medium have been identified by 57Fe Mössbauer spectroscopy of Fe/N/C catalysts containing 0.03 to 1.55 wt% Fe, which were prepared by impregnation of iron acetate on carbon black followed by heat-treatment in NH3 at 950 °C. Four different Fe-species were detected at all iron concentrations: three doublets assigned to molecular FeN4-...