Abstract: | Various compositions of the ZrO2/Nb2O5 system were synthesized and the experimental conditions for obtaining reproducible results were established. The gel was precipitated at constant pH = 10, aged at room temperature for 18 h and, after filtration, dried at 110 °C for 24 h. The phase diagram of the ZrO2/Nb2O5 system was established between 600 and 1300 °C. Phase transitions of ZrO2 and Nb2O5 were observed with XRD; and two ternary compounds, 6 ZrO2 · Nb2O5 and 12 Nb2O5 · ZrO2, were identified. The samples with a Nb2O5 content between approximately 10 and 40 mole% showed the greatest specific area and are thus best for use as catalyst supports. |