AlPO4-5 and ZrAPO-5 molecular sieves were synthesized hydrothermally and ch
aracterized by XRD, SEM, MASNMR, FTIR, adsorption studies and TPD of ammoni
a. The results indicated that Zr was isomorphously substituted in the AlPO4
-5 structure. Increase in Bronsted and Lewis acidity was observed which res
ulted in increased activity and stability in m-xylene isomerization reactio
n. (C) 1999 Elsevier Science B.V. All rights reserved.