Various compositions of the ZrO2/Nb2O5 system were synthesized and the expe
rimental conditions for obtaining reproducible results were established. Th
e gel was precipitated at constant pH = 10, aged at room temperature for 18
h and, after filtration, dried at 110 degreesC for 24 h. The phase diagram
of the ZrO2/Nb2O5 system was established between 600 and 1300 degreesC. Ph
ase transitions of ZrO2 and Nb2O5 were observed with XRD; and two ternary c
ompounds, 6ZrO(2). Nb2O5 and 12Nb(2)O(5). ZrO2, were identified. The sample
s with a Nb2O5 content between approximately 10 and 40 mole% showed the gre
atest specific area and are thus best for use as catalyst supports.