SYNTHESIS AND CHARACTERIZATION OF CATALYST SUPPORTS WITH COMPOSITION XSIO(2)-XALPO(4)-(100-2X)TIO2

Several xSiO(2)-xAlPO(4)-(100-2x)TiO2 catalyst supports were investiga ted with regard to their structural and textural properties. Their tex tural properties were found to depend on their chemical composition. L ow titania content (5 mol%) led to an increase of the BET surface area , whereas a higher titania content virtually did not modify the BET sp ecific surface area, but did lead to a decrease of the pore volume. X- ray diffraction (XRD) and infrared (IR) data are in accordance with a good dispersion of titanium (up to 15 mol%) in the matrix. X-ray diffr action showed that the silica-aluminum phosphate matrix was present as an amorphous phase in all catalysts calcined at 973 K, but crystallin e domains of anatase were found in supports containing 20 mol% or more titania. (C) 1998 Elsevier Science Ltd.