| 摘要 |
<p>Process for preparing a modified zeolite Y which process comprises subjecting zeolite Y having a silica to alumina molar ratio of at least 10 to calcination at a temperature of from 700 to wherein (i) the steam partial pressure is at most 0.06 bar at a temperature of from 700 to , (ii) the steam partial pressure is at most 0.08 bar at a temperature of from 800 to , (iii) the steam partial pressure is at least 0.03 bar at a temperature of from 850 to , and (iv) the steam partial pressure is at least 0.05 bar at a temperature of from 900 to 950 °C and (v) the steam partial pressure is at least 0.07 bar at a temperature of from 950 to , a modified zeolite Y obtainable by such process, zeolite Y having a silica to alumina molar ratio of at least 10, the infrared spectrum of which has a peak at 3700 cmbut substantially no peaks at 3605 and 3670 cmand zeolite Y having a silica to alumina molar ratio of at least 10, which zeolite Y has an acidity as measured by exchange with perdeuterated benzene of at most 20 micromole/gram.</p> |
