The structures of mesoporous solids of abbreviated formula Al100PxVy where
x, y=0, 5, 10 have been characterised by multinuclear magnetic resonance te
chniques. P-31 MAS spectra indicate that two phosphorus environments (three
fold or fourfold O-Al coordination) are incorporated within the aluminium n
etwork. V-51 magic-angle spinning (MAS) spectra suggest that vanadium speci
es are not (or only weakly) incorporated into the alumina network, forming
V2O5-like and tetrahedral species at the surface of the pores. Al-27 MAS sp
ectra show that amorphous AlPO4 species are formed upon addition of phospho
rus, already occurring for the lower phosphorus input. However, Al-27 tripl
e-quantum (3Q)-MAS cannot detect this amorphous AlPO4 phase, therefore indi
cating distorted environments close to the surface. For the Al100P10V10 sam
ple, crystalline AlPO4 is detected. P-31-{Al-27} and P-31-{V-51} TRAPDOR ex
periments confirm that all the phosphorus atoms are surrounded by at least
three aluminium atoms in the second coordination sphere, and suggest the he
terogeneous location of vanadium species at the surface of the mesopores.