HIGHLY DISPERSED PHOSPHATE SUPPORTED IN A BINARY SILICA-TITANIA MATRIX - PREPARATION AND CHARACTERIZATION

Titanium phosphate supported in a mixed oxide matrix was prepared by r eacting SiO2/TiO2, obtained from the sol-gel process, with phosphoric acid. HPO42- is the species present in the matrix, and it is immobiliz ed by the Ti-O-P bond on the surface. The titanium phosphate is highly and homogeneously dispersed in the SiO2/TiO2 matrix, with the domain of titanium oxide particles about 1 nm, estimated from the UV absorpti on band threshold. The specific surface areas, determined by the BET m ultipoint method, changed between 397 and 755 m(2) g(-1) and the avera ge pore volumes between 0.38 and 0.63 mL g(-1) for samples prepared wi th different contents of titanium phosphate. The titanium hydrogenphos phate is thermally very stable and showed a high proton exchange capac ity between 0.50 and 1.10 mmol g(-1).