Thermal behaviour of pure LiN3, NaN3, CsN3 and their mixture with the respective LiY-FAU, NaY-FAU, CsY-FAU zeolite was investigated by means of thermogravimetry and IR spectroscopy. Thermodesorption of CO2 was applied to compare the basicity of the alkali ionexchanged Y zeolites. Two of the investigated systems, the NaN3/NaY-FAU and the CsN3/CsY-FAU gave single, well defined and reproducible azide decomposition features rendering these samples to apply as catalyst precursors for preparation of zeolite with basic character.
Ion-exchange of transition metal ions into montmorillonite was investigated using two different ion-exchange procedures. Performing ion-exchange from aqueous solution of the respective metal ion leads to material possessing measurable BrØnsted acidity, while the solid-state exchange materials show predominantly Lewis acidity.
Authors:I. Pálinkó, I. Kiricsi, Gy. Tasi, and K. Varga
Natural montmorillonite was pillared by various polyhydroxy cations. The resulting pillared layer clays (PILCs) were characterized by X-ray fluorescence, X-ray diffraction (XRD) and infrared (IR) spectroscopies. The thermal behaviour of Al-PILC was investigated in detail by a combonation of XRD, derivatography IR spectroscopy and a comparison to natural montmorillonite is given. It was found that thermal stability of Al-PILC is lower than that of natural montmorillonite. However, heat treatment in the stability region results in significant sintering of natural montmorillonite, while the interlayer spacing of Al-PILC is hardly affected.
Authors:T. Braun, H. Rausch, L. Bíró, Z. Konya, and I. Kiricsi
By using instrumental neutron activation analysis (INAA) it has been shown that some pristine carbon SWNT's and MWNT's of
different makes, contain a multitude of trace element impurities at various concentration levels including also amounts which
can be considered as nanoelectronically dopant quantities. The same holds for the above mentioned carbon nanotubes also after
their inadequately so-called purification.