Kedves Kollegák!

November 4-én 13.30-kor egy indiai vendégünk, Dr. A.V. Ramaswamy tart előadást az IKI-ben a  XXI/B épület 3.emeleti tanácstermében:

 Chemical States and Redox properties of Mn/CeO2-TiO2 Nano composites

 címmel. Az előadásra minden érdeklődőt szeretettel várunk.

 Guczi László távollétében
 Schay Zoltán

Az előadás kivonata:

 The catalytically important Mn/CeO₂-TiO₂ samples having up to 5 wt% of Mn  have been prepared by different methods, viz., solution combustion, co-precipitation and wet impregnation. Based on a detailed characterization of the samples by a variety of techniques, we show how the nature of Mn species, its valent states and redox properties are influenced by the
method of preparation.  The samples prepared by solution combustion method showed high thermal stability even at temperatures of 1323 K, whereas samples prepared by conventional methods lost their structural integrity at high
 temperatures due to fast sintering. We elucidate that Ti incorporation into the ceria matrix alters the redox properties of both cerium and manganese ions.  The nature of the fuel used in combustion synthesis did not have significant effect on the oxidation state of Mn.  Employing PEG as fuelin the combustion process, one can obtain thermally stable, nano-crystalline
 Mn/CeO₂-TiO₂ sample with high phase purity.