A mesoporous form of titanium phosphate has been prepared by reaction betwe
en phosphoric acid solution and either titanium propoxide or titanium chlor
ide in the presence of trimethylammonium surfactants. The surfactant can be
almost completely removed by extraction using acidified ethanol. The surfa
ce area of the extracted samples depends closely on the pH of the reaction
medium, and the reaction temperature, and the highest surface areas, around
740 m(2) g(-1) were obtained for materials prepared at pH 3. This surface
area is partially lost when the extracted titanium phosphate is calcined, a
lthough the mesoporous character is retained. P-31 NMR spectroscopy shows t
he ethanol-extracted sample to be rich in hydrogen phosphate (HPO42- and H2
PO4-) groups, which undergo partial condensation after calcination. These h
ydrogen phosphate groups are responsible for the high surface acidity deter
mined, and for its evolution after calcination: the total numbers of surfac
e acidic sites of ethanol-extracted titanium phosphate and calcined titaniu
m phosphate, evaluated using two-cycle adsorption of ammonia from the gas p
hase at 80 degrees C, are 900 and 340 mu mol g(-1) respectively.