OMPOSITE CERIA/SILICA MATERIALS OF 10 AND 20% (W/W) WERE PREPARED BY CALCINATION, AT 650 ◦C FOR 3 H, OF THE XEROGELS OBTAINED BY MIXING THE CORRESPONDING AMOUNT OF A CERIA PRECURSOR WITH FRESHLY PREPARED SOLS OF SPHERICAL SILICA PARTICLES (STÖBER PARTICLES) IN THEIR MOTHER LIQUORS. TWO DIFFERENT CERIA PRECURSORS WERE EXAMINED IN THIS INVESTIGATION. THE FIRST WAS A GEL PRODUCED ... إقراء المزيد