| 摘要 |
Highly active, hydrothermally stable and ammonia-stable Y zeolite compositions are disclosed, which compositions are useful as adsorbents, hydrocarbon conversion catalysts, and as acidic supports for catalytic metals. The stabilized Y zeolite composition is prepared from a sodium Y zeolite by a novel sequence of: (1) partial exchange of ammonium ions for sodium ions, (2) steam calcination under controlled conditions of time, temperature and steam partial pressure, and (3) further ion exchange of ammonium ions for sodium ions to reduce the final Na2O content to below about one weight-percent.
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