发明名称 |
Catalyst supports having promoter oxide gradient, resulting catalyst and method of making the supports |
摘要 |
Catalysts which are suitable for auto exhaust use are made with a promoter oxide that is deposited in a concentration gradient. A solution of the promoter oxide precursor, e.g., cerous nitrate solution, is impreganted uniformly into the pore structure of a support which can be in the form of beads or extrudates to a level just below the full incipient wetness. The impregnated support is then treated with a gaseous base such as ammonia, under dynamic conditions such as tumbling (to insure uniformity), which causes the precipitation of the promoter oxide in the form of a radial concentration gradient. The resulting product is then dried and calcined at sufficiently high temperature to effect complete conversion of the promoter precursor to its oxide form, e.g., CeO2.
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申请公布号 |
US5102850(A) |
申请公布日期 |
1992.04.07 |
申请号 |
US19900600374 |
申请日期 |
1990.10.17 |
申请人 |
W. R. GRACE & CO. - CONN. |
发明人 |
SANCHEZ, MOISES G.;SCHMIDT, STEPHEN R.;ERNEST, MICHAEL V. |
分类号 |
B01D53/94;B01J23/40;B01J23/58;B01J23/63;B01J23/648;B01J35/10 |
主分类号 |
B01D53/94 |
代理机构 |
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代理人 |
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主权项 |
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地址 |
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