New binary systems Mg-M-O (M = Y, La, Ce):: Synthesis and physico-chemical characterization

New binary oxide Mg-M-O (M = Y, La, Cc) systems are obtained by co-precipitation and characterized by adsorption methods, X-ray diffraction method (XRD), X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared (FTIR) spectroscopy of adsorbed probe molecules (CO and CDCl3). It is Shown that Mg-Y-O systems after calcination at 450-750 degrees C represent the physical mixtures of MgO and Y2O3, while the components of Mg-La(Ce)-O systems interact to form La2MgOx and (Ce,Mg)O-2 solid solutions, respectively. From XPS data, the surface of the binary systems is enriched with lanthanide ions. Addition of approximate to 5 mol% M2O3 to MgO results in an increase in concentrations of strong and weak Lewis acidic sites, the content of the latter being much higher and changing in the series: MgO < Mg-Ce-O < Mg-La-O < Mg-Y-O. At the same time basic sites become stronger in the binary systems but their total content decreases in comparison to that in individual MgO. Mg-M-O samples containing approximate to 5 mol% M2O3 are highly-dispersed and characterized by bimodal porous texture. (c) 2005 Published by Elsevier Inc.