It was useful to study the effect of addition (TiO2) Anatase as a support on structural properties and surface chemistry of the catalyst. This precursor is prepared in an alternative method never mentioned in the literature. Route (A) depends on the reaction of the technical grade (V2O5) with (o- H3PO4 ) in order to prepare the intermediate phase (VOPO4.2H2O) which is then reduced by a mixture of (benzyl alcohol and isobutanol) to reach the assigned phase VO (H2PO4)2 .

The structural properties and surface chemistry of Vanadyl Acid Phosphate and the intermediate phase prepared by route (A) and Vanadyl Hydrogen Phosphate Hemi hydrate prepared by route (B) are studied after carrying out physical and chemical analysis in international known laboratories in U.S.A, Germany, Republic of Ukraine and U.A.E. by using techniques devoted in structural and surfaces studies.

The prepared phase's identification was carried out by using X- ray diffraction (XRD). The results of phases identification show the co- existence of traces of other phases like VO (H2PO3)2 with the dominated main phase prepared by route (A).

The differential thermo gravimetric behaviors for the precursors were studied. This study highlights only the supported and unsupported precursors in order to assign the effect of TiO2 (Anatase) on the thermal behavior,

The comparison of FTIR spectrum of prepared supported and unsupported phases with laboratory grade and technical grade of Vanadium Pentoxide are achieved. The obtained results emphasis on the presence of wide shifts in the band positions

Vanadium ion oxidation state and the percentage distribution for V (5+), V (4+) and V (3+) oxidation states are studied for supported and unsupported phases by using Redox titration technique.

Desorption at Argon temperature technique was used for specific surface area determination. The results state that there are significant increases in specific surface area when adding support to intermediate phase VOPO4.2H2O.

The X- ray photoelectron spectroscopy (XPS) technique was used in order to study the surface chemistry of the two precursors (VOHPO4.0.5H2O), and VO (H2PO4)2 and the intermediate phase VOPO4.2H2O. The results pointed out the presence of structural elements (V, P, O), and detectable percentage of inorganic impurities on the surface.

The combination between energy dispersive X-ray (EDX) techniques with Scanning Electron Microscope (SEM) technique was carried out on samples in order to reach the elementally atomic percentage down to depth of 1 µm from the surface. The results indicated the presence of TiO2 in selected spots.