US4265834A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for the catalytic hydrogenation of nitrobenzene
Assignee: Bayer AG
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Filing: 1979-08-16
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Granted: 1981-05-05
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Expires: 1999-08-16
Abstract
Abstract A process for the hydrogenation of nitrobenzene to aniline is described wherein the nitrobenzene is contacted with hydrogen in the presence of a multi-component supported catalyst containing 1 to 20 grams of noble metal per liter of support and 1 to 20 grams per liter of support of one or more transition metal of the Groups IVa, Va, or VIa of the Periodic Table. The catalyst can contain 1 to 20 grams per liter of support of a further transition group element or of a member of the main group. The catalyst is one which has been prepared by a process involving pretreatment of the support with a base prior to impregnation with the catalytically active substances, followed by drying to a residual moisture content of less than 10 percent of the maximum absorbency of the support.
Inventors
- 👤 Udo Birkenstock
- 👤 Burkhard Lachmann
- 👤 Josef Metten
- 👤 Herbert Schmidt
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 13:20
CPC Classifications
C; C07; C07C; C07C209/00; C07C209/30; C07C209/32; C07C209/36; B; B01; B01J; B01J23/00; B01J23/38; B01J23/54; B01J23/56; B01J23/64; B01J23/648; B01J23/6482; B01J37/00; B01J37/02; B01J37/0201; B01J37/0205; B01J2523/00; B01J37/16; B01J37/18
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
167 words
In a gas phase process for the catalytic hydrogenation of nitrobenzene to aniline wherein nitrobenzene is contacted with hydrogen in the presence of a catalyst, the improvement wherein said catalyst is a multi-component supported catalyst having a BET surface area of less than 20 square meters per gram and comprises 1 to 20 grams of a noble metal per liter of support and 1 to 20 grams of one or more transition metals of Groups IVa, Va, or VIa of the Periodic Table of the Elements per liter of support, said catalyst having been prepared by pretreating the support, prior to impregnation thereof with said noble method or said transition metal, with a base, thereafter drying the so-pretreated material to a residual moisture content of less than 10 percent of the maximum absorbency of the support and thereafter impregnating the support with 1 to 20 grams of said noble metal per liter of support and 1 to 20 grams of said transition metal per liter of support.
Claim 2
Dependent Claim
167 words
In a gas phase process for the catalytic hydrogenation of nitrobenzene to aniline wherein nitrobenzene is contacted with hydrogen in the presence of a catalyst, the improvement wherein said catalyst is a multi-component supported catalyst having a BET surface area of less than 20 square meters per gram and comprises 1 to 20 grams of a noble metal per liter of support and 1 to 20 grams of one or more transition metals of Groups IVa, Va, or VIa of the Periodic Table of the Elements per liter of support, said catalyst having been prepared by pretreating the support, prior to impregnation thereof with said noble method or said transition metal, with a base, thereafter drying the so-pretreated material to a residual moisture content of less than 10 percent of the maximum absorbency of the support and thereafter impregnating the support with 1 to 20 grams of said noble metal per liter of support and 1 to 20 grams of said transition metal per liter of support.
Claim 3
Dependent Claim
31 words
A process according to claim 1 wherein said catalyst additionally contains 1 to 20 grams per liter of support of a further transition group element or element of the main group.
Claim 4
Dependent Claim
35 words
A process according to claim 2 wherein the element of said further transition group element or main group element is an element of Group IIb, IVb, or Vb of the Period Table of the Elements.
Claim 5
Dependent Claim
25 words
A process according to claim 1 wherein said noble metal is present on said support in elemental form or in the form of a compound.
Claim 6
Dependent Claim
42 words
A process according to claim 4 wherein said transition metal of the Group IVa, Va, or VIa of the Periodic Table of the Elements is present on said support in the form of an element or in the form of a compound.
Claim 7
Dependent Claim
33 words
A process according to claim 2 wherein said further transition metal or transition metal of the main group is present on said support in elemental form or in the form of a compound.
Claim 8
Dependent Claim
25 words
A process according to claim 1 wherein said support material is α-alumina with a BET surface area of less than 10 square meters per gram.
Claim 9
Dependent Claim
57 words
A process according to claim 1 wherein the catalyst is prepared by drying the support material which has been pretreated with a base to a residual moisture content of less than 1 percent of the absorbency of the support before impregnating the same with said noble metal and said metal of the Group IVa, Va, or VIa.
Claim 10
Dependent Claim
46 words
A process according to claim 1 wherein the hydrogenation is carried out in the presence of a supported catalyst containing 1 to 10 grams palladium, 5 to 15 grams of one of the metals vanadium, niobium, tantalum, chromium, molybdenum, tungsten or titanium per liter of support.
Claim 11
Dependent Claim
26 words
A process according to claim 9 wherein said catalyst additionally contains 1 to 10 grams of a metal of the group of lead, zinc and bismuth.
Claim 12
Dependent Claim
43 words
A process according to claim 1 wherein the hydrogenation is carried out in the presence of a supported catalyst containing per liter of support 1 to 10 grams of palladium, 5 to 15 grams of vanadium and 1 to 10 grams of lead.
Claim 13
Dependent Claim
19 words
A process according to claim 1 wherein the base employed for the pretreatment is sodium hydroxide or potassium hydroxide.
Claim 14
Dependent Claim
33 words
A process according to claim 1 wherein said catalyst comprises 1 to 20 grams of palladium, 1 to 20 grams of molybdenum and 1 to 10 grams of lead, per liter of support.
Claim 15
Dependent Claim
22 words
A process according to claim 1 wherein said catalyst comprises 1 to 20 grams of palladium and 20 grams grams of chromium.
Claim 16
Dependent Claim
33 words
A process according to claim 1 wherein said catalyst comprises 1 to 20 grams of palladium, 1 to 20 grams of vanadium, and 1 to 10 grams of zinc, per liter of support.
Claim 17
Dependent Claim
17 words
A process according to claim 1 wherein the hydrogenation is carried out at 150° to 350° C.
Claim 18
Dependent Claim
15 words
A process according to claim 1 wherein the hydrogenation is carried out at 200°-300° C.
References Cited (Backward Citations)
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1984-05-04 | 1984-11-03 | 1985-05-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-05-04 | 1988-11-03 | 1989-05-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-05-04 | 1992-11-03 | 1993-05-05 | $7700.00 | Window Closed / Lapsed |