Structure and acid-basic properties of the surface of titanium oxides modified by phosphorus and aluminum and prepared by the alkoxo method 2. Study of the active surface of titanium oxides

The data of temperature-programmed desorption of ammonia from the surface o f oxide systems and IR spectroscopy were used to demonstrate that the stren gth of the surface acid sites in titanium oxides prepared by the alkoxo met hod and modified by aluminum decreases with respect to that in nonmodified titanium oxide. Modification of titanium oxide with P3+ ions from ethriol p hosphite almost completely suppresses the acid properties. Modified oxides are able to chemisorb water. XANES data suggest that modification of titani um oxide with phosphorus ions increases the electron density on the titaniu m atoms and, correspondingly, the basicity of the materials.