Synthesis and characterization of catalyst supports with composition xSiO2–xAlPO4–(100–2x)TiO2

Several xSiO2–xAlPO4–(100–2x)TiO2 catalyst supports were investigated with regard to their structural and textural properties. Their textural properties were found to depend on their chemical composition. Low titania content (5 mol%) led to an increase of the BET surface area, whereas a higher titania content virtually did not modify the BET specific 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 diffraction showed that the silica–aluminum phosphate matrix was present as an amorphous phase in all catalysts calcined at 973 K, but crystalline domains of anatase were found in supports containing 20 mol% or more titania.