EP0862494A1 - Procede de preparation d'un catalyseur d'hydrogenation - Google Patents

Procede de preparation d'un catalyseur d'hydrogenation

Info

Publication number
EP0862494A1
EP0862494A1 EP96933397A EP96933397A EP0862494A1 EP 0862494 A1 EP0862494 A1 EP 0862494A1 EP 96933397 A EP96933397 A EP 96933397A EP 96933397 A EP96933397 A EP 96933397A EP 0862494 A1 EP0862494 A1 EP 0862494A1
Authority
EP
European Patent Office
Prior art keywords
platinum
reducing agent
selective reducing
amount
poisoned
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
EP96933397A
Other languages
German (de)
English (en)
Inventor
Daniel Heineke
Christopher William Rieker
Jozef Oostvogels
Dany Postelmans
Heinz-Walter Schneider
Alfred Thome
Günther Achhammer
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
BASF SE
Original Assignee
BASF SE
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by BASF SE filed Critical BASF SE
Publication of EP0862494A1 publication Critical patent/EP0862494A1/fr
Withdrawn legal-status Critical Current

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Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J23/00—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00
    • B01J23/38—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of noble metals
    • B01J23/40—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of noble metals of the platinum group metals
    • B01J23/42—Platinum
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J23/00—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00
    • B01J23/90—Regeneration or reactivation
    • B01J23/96—Regeneration or reactivation of catalysts comprising metals, oxides or hydroxides of the noble metals
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J37/00—Processes, in general, for preparing catalysts; Processes, in general, for activation of catalysts
    • B01J37/16—Reducing
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
    • C01B21/00—Nitrogen; Compounds thereof
    • C01B21/082—Compounds containing nitrogen and non-metals and optionally metals
    • C01B21/14—Hydroxylamine; Salts thereof
    • C01B21/1409—Preparation
    • C01B21/1418—Preparation by catalytic reduction of nitrogen oxides or nitrates with hydrogen
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
    • Y02P20/00—Technologies relating to chemical industry
    • Y02P20/50—Improvements relating to the production of bulk chemicals
    • Y02P20/584—Recycling of catalysts

Definitions

  • the present invention relates to an improved process for the preparation of a hydrogenation catalyst by reduction of platinum in the oxidation state of +4 with a selective reducing agent in an acidic aqueous medium in the presence of a
  • the invention further relates to the use of alkali metal formates for the preparation of hydrogenation catalysts, hydrogenation catalysts produced according to the invention, a process for the preparation of hydroxylammonium salts and a process for the regeneration of hydrogenation catalysts based on platinum.
  • Precious metals such as palladium, platinum or ruthenium, which are applied to various supports such as silicon dioxide, aluminum oxide, graphite or activated carbon, are suitable for the hydrogenation of organic and inorganic compounds 25, as from "Catalytic hydrogenations in the organic chemical laboratory", F. Zimalkowski , John Enke Verlag, Stuttgart (1965) is known. 30
  • DE-C 40 22 853 describes that by using platinum-graphite supported catalysts with a grain size of the graphite between 1-600 ⁇ m, the selectivity with respect to hydroxylamine in the hydrogenation of nitrogen monoxide can be increased.
  • platinum-graphite support catalysts which are obtained by precipitating platinum on suspended graphite supports, optionally with the addition of poisoning agents such as sulfur, selenium, arsenic or tellurium compounds.
  • poisoning agents such as sulfur, selenium, arsenic or tellurium compounds.
  • Such catalysts are suitable for the catalytic hydrogenation of nitrogen monoxide. These catalysts have the disadvantage that the reactivity and selectivity decrease rapidly with prolonged use.
  • DE-C 40 22 851 describes that in the production of hydroxylamine by hydrogenation of nitrogen monoxide in the presence of platinum-graphite supported catalysts, the selectivity is related to the apparent density, the compressive strength and porosity of the graphite support.
  • DE-A 43 11 420 describes the preparation of a hydrogenation catalyst which can be obtained by treating a platinum metal salt with finely divided sulfur in the presence of a dispersant and then reducing the platinum metal salt to metallic platinum metal.
  • Sodium formate is also mentioned as the reducing agent, but according to the teaching of DE-A 43 11 420 formic acid is particularly preferred. Tests with sodium formate were not carried out in the corresponding DE document.
  • the particle size of the platinum has a decisive role in the stability of the catalyst, the selectivity and the by-product spectrum.
  • the object of the present invention was therefore to provide an improved process for the preparation of hydrogenation catalysts which ensures longer service lives of the catalysts used with at least the same selectivity and high space-time yield. Furthermore, a minimization of the by-products, in particular dinitrogen monoxide and ammonia, should be achieved.
  • an improved process for the preparation of a hydrogenation catalyst by reduction of platinum in the oxidation stage of +4 (Pt (IV)) with a selective reducing agent in an acidic aqueous medium in the presence of a carbon-containing carrier to platinum in the oxidation stage +2 (Pt (II)), subsequent poisoning of the platinum thus obtained with a sulfur-containing selective reducing agent, and then reduction of the partially poisoned platinum to metallic platinum (Pt (0)) and subsequent workup in a manner known per se by:
  • Pt (II) partially poisoned with a sulfur-containing selective reducing agent, the sulfur-containing selective reducing agent being used in an amount which corresponds to from 15 to 70 mol% of the amount of a selective reducing agent which was required in order to use Pt (IV) to Pt (II), provided the amount of Pt (IV) corresponds to the amount of Pt (II) to be poisoned, and then the partially poisoned Pt (II) with an alkali metal formate Pt (0) reduced, or
  • alkali metal formates for the preparation of hydrogenation catalysts, hydrogenation catalysts prepared according to the invention, a process for the preparation of hydroxylammonium salts and a process for the regeneration of hydrogenation catalysts based on platinum were found.
  • the amount of the sulfur-containing selective reducing agent is chosen so that it is used in an amount which corresponds to from 15 to 70, preferably from 20 to 65, mol% of the amount of a selective reducing agent which is required in order to use Pt (IV) to reduce to Pt (II), under the condition that the amount of Pt (IV) corresponds to the amount of Pt (II) to be poisoned.
  • platinum is poisoned in an oxidation state greater than +2 and then reduced to Pt (0) or simultaneously with an alkali metal formate.
  • alkali metal formates preferably lithium formate, sodium formate and kaiium formate, particularly preferably sodium formate, are used.
  • variant (a) uses platinum in the oxidation state +2, which can be obtained by reducing platinum with an oxidation number greater than +2, particularly preferably Pt (IV), with a selective reducing agent.
  • selective reducing agent can be the sulfoxyl acid, in particular the well-known under the name Rongalit ® Ein ⁇ effective product of formaldehyde on hyposulfite, sulfur dioxide and sulphites use, typically dithionites, especially sodium (Blankit ®) derivatives.
  • the selective reducing agent is used in an amount equivalent to the dissolved platinum with an oxidation state greater than 2, preferably +4, equivalent.
  • oxidation level +2 eg Blankit ®
  • the reduction is first carried out according to the invention only up to the level of platinum in oxidation level +2.
  • the partial poisoning then takes place according to the invention subsequently by adding a certain amount, which is required beyond the reduction of Pt (> II), preferably Pt (IV), to Pt (II), from 15 to 70, preferably from 20 to 65 mol % corresponds to the amount used to reduce Pt (IV) to Pt (II).
  • the reduction with the alkali metal formate then takes place according to the invention.
  • a compound is used as the poisoning agent which is not able to reduce platinum in an oxidation state of greater than +2, in particular Pt (IV), to Pt (II), variant (b), then according to the invention the platinum is first poisoned and then, or simultaneously with an alkali metal formate as reducing agent, it reduces to platinum (0) (metallic platinum).
  • Such poisoning agents are customary poisoning agents based on sulfur, selenium, arsenic or tellurium such as sodium dithionite, alkali thiosulfates, hydrogen sulfide, alkali sulfide, alkali polysulfides, thiourea, telluric acid or arsenic acid or combinations thereof.
  • the molar ratio of platinum to sulfur, selenium, arsenic or tellurium to be poisoned is usually chosen in the range from 20: 1 to 3: 1, preferably from 10: 1 to 5: 1.
  • the partial poisoning is usually carried out according to methods known per se, as described, for example, in DE-C 40 22 853.
  • the reduction with alkali metal formate to metallic platinum is carried out.
  • the platinum (IV) compound used is, in particular, the waterless compounds such as hexachloroplatinic acid and their alkali metal and ammonium salts, such as disodium, dipotassium and diammonium hexachloroplatinate.
  • the molar ratio of platinum used to the alkali metal formate is usually chosen in the range from 1000: 1 to 10: 1, preferably from 100: 1 to 20: 1.
  • Suspended graphite or activated carbons are generally used as the carbon-containing carrier, particularly preferably those electrographite grades that have a grain size in the range from 0.5 to 600 ⁇ m, preferably from 1 to 70, particularly preferably from 2 to 50 ⁇ m.
  • the amount of platinum is generally from 0.2 to 2, preferably from 0.5 to 1 wt .-%, based on the total mass of platinum-graphite carrier catalyst.
  • the reduction of the platinum is carried out according to the invention in an aqueous solution, the weight ratio of water to platinum generally being selected from 1000: 1 to 100: 1, preferably from 500: 1 to 100: 1.
  • the reduction is also carried out in slightly acidic form, the pH usually being from 4.5 to less than 7, preferably from 5 to 6.
  • the pH is generally adjusted by adding buffer salts such as alkali metal acetate, in particular sodium acetate.
  • variant (a) is used as the selective reducing agent Blankit ® (sodium dithionite).
  • Blankit ® sodium dithionite
  • Blankit ® sodium dithionite
  • This potential characterizes the poisoning state of the catalyst and is usually in the range from 440 mV to 200 mV, preferably from 270 mV to 340 mV.
  • the molar ratio of alkali metal formate to platinum is generally chosen in the range from 1000: 1 to 10: 1, preferably
  • the temperature during the reduction is generally chosen in the range from 50 to 95 ° C., preferably from 60 to 90 ° C.
  • the pH after reduction to metallic platinum essentially depends on the type of reducing agent chosen and is usually in the range from pH 5 to 8, particularly preferably from 5 to 6.5.
  • the particle size of the platinum particles produced according to the invention has generally not been greater than 3.5 nm according to previous observations by determining the line width at half the height by means of X-ray diffraction.
  • the catalysts obtained by the process according to the invention are suitable both for the hydrogenation of organic and of inorganic compounds.
  • the catalysts according to the invention are preferably used for the hydrogenation of olefinically or acetylenically unsaturated compounds, furthermore for the hydrogenation of carboxylic acids, aldehydes or ketones to the corresponding alcohols or of nitriles to the corresponding amines. Furthermore, the catalysts according to the invention are suitable for the hydrogenation of inorganic substances such as oxygen, but in particular for the production of hydroxylammonium salts by hydrogenation of nitrogen monoxide in aqueous mineral acids.
  • a molar ratio of hydrogen to nitrogen monoxide of 1.5: 1 to 6: 1, preferably from 3.5 to 5: 1, is generally maintained. According to the previous observations, particularly good results are obtained if it is ensured that a molar ratio of hydrogen to nitrogen monoxide of 3.5: 1 to 5: 1 is maintained in the reaction zone.
  • Ci-Cs-monocarboxylic acids such as formic, acetic, propionic, butteric and valeric acid, preferably formic acid and acetic acid, are advantageously used as acids.
  • Acidic salts such as ammonium bisulfate are also suitable. As a rule, 4 to 6 normal aqueous acids are used and the acid concentration is usually not allowed to drop below 0.2 in the course of the reaction.
  • the hydrogenation of nitrogen monoxide is generally carried out at a temperature from 30 to 80, preferably from 35 to 60 ° C. Furthermore, the pressure during the hydrogenation is usually chosen in the range from 1 to 30, preferably 1 to 20, bar (absolute).
  • the ratio of mineral acid to catalyst essentially depends on the platinum metal and the reactor pressure and, in the case of platinum, is generally in the range from 1 to 100. preferably 30 to 80 g of platinum-graphite catalyst per liter of mineral acid.
  • the catalyst in particular in the preparation of hydroxylammonium salts, is treated in an acidic solution before the hydrogenation, expediently in the mineral acid in which the hydrogenation is to be carried out with hydrogen (“activation”).
  • Used platinum metal catalysts can be regenerated with the aid of the process according to the invention by usually dissolving the platinum metal of the catalyst using an acid or an acid mixture and, if appropriate, removing insoluble constituents.
  • the platinum metal salt solution obtained is then neutralized, and the platinum metal salt is then treated by the process according to the invention described above.
  • the catalysts according to the invention are superior to known catalysts for the same purpose in terms of activity, selectivity and service life.
  • a spatula tip of the powder to be examined was placed in one liter of a 0.1% by weight aqueous Nekanil 910 solution (BASF AG; Nekanil 910 is a nonylphenol reacted with 9 to 10 mol ethylene oxide; properties: water-clear, viscous Liquid; non-ionic, density at 20 ° C: 1.04 g / cm 3 ; pour point: below -10 ° C; pH of a 1% by weight solution (6.5 to 8.5).
  • the mixture to be examined thus obtained was subjected to an ultrasound treatment for 1 min.
  • the particle size of the platinum particles was determined by means of X-ray diffraction by determining the line width at half the height. example 1
  • the catalyst prepared in this way was separated from the reaction mixture by filtration through a glass frit and washed with distilled water until the pH of the wash water was no longer in the acidic range.
  • the dried catalyst contained 0.5% by weight of platinum.
  • Example 2 The procedure was as in Example 1, with the differences that 56 mol% of sodium dithionite, based on the amount used for the reduction to platinum (II), was used for poisoning, and that 6.25 ml was used to precipitate the platinum to zero conc. Formic acid were used. The results are shown in the table below.
  • Particle sizes of 28 to 50 mm and 0.5310 g of hexachloroplate IV acid 6-hydrate were mixed with 40 ml of an aqueous solution containing 3.87 ml of concentrated hydrochloric acid and 0.87 ml of concentrated nitric acid at 80 ° C. overnight touched.
  • Sodium carbonate was added to the suspension obtained until a pH of 2.75 was reached.
  • 2.5 g of sodium acetate were added for buffering.
  • 6.25 mg of elemental sulfur was added and, after a waiting time of 2 minutes, 14.1 g of a 40% by weight aqueous sodium formate solution (83 mmol) were added to the suspension thus obtained and the mixture was stirred at 80 ° C. for 4 hours. After this time, no more platinum was detectable with hydrazine hydrate (which gives a black precipitate in alkaline solution in the presence of platinum).
  • the catalyst thus prepared was separated from the reaction mixture by filtration through a glass frit and washed with distilled water until the pH of the
  • wash water was no longer in the acidic range.
  • the dried catalyst contained 0.5% by weight of platinum.
  • Example 2 The procedure was as in Example 2 with the difference that 6.25 mg of elemental sulfur for poisoning, and that 6.25 ml of conc. Formic acid were used. The results are shown in the table below.

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  • Chemical & Material Sciences (AREA)
  • Organic Chemistry (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Engineering & Computer Science (AREA)
  • Materials Engineering (AREA)
  • Inorganic Chemistry (AREA)
  • Catalysts (AREA)

Abstract

On prépare un catalyseur d'hydrogénation par réduction de platine au stade d'oxydation +4 (Pt (IV)) avec un agent réducteur sélectif dans un milieux aqueux acide en présence d'un substrat carboné de platine au stade d'oxydation +2 (Pt (II)), par empoisonnement du platine ainsi obtenu avec un agent réducteur sélectif soufré et par réduction du platine partiellement empoisonné en platine métallique (PT (0)), qui est ensuite traité de manière connue en soi. A cet effet (a) on empoisonne partiellement le Pt (II) avec une quantité d'un agent réducteur sélectif soufré comprise entre 15 et 70 % en moles de la quantité d'agent réducteur sélectif soufré qui serait nécessaire pour réduire le Pt (IV) en Pt (II), à condition que la quantité de Pt (IV) corresponde à la quantité de PT (II) utilisée que l'on veut empoisonner, puis on réduit le Pt (II) partiellement empoisonné en Pt (0) avec un formiate de métal alcalin, ou (b) on empoisonne partiellement du platine à un stade d'oxydation supérieur à +2 et on le réduit ensuite ou en même temps en Pt (0) avec un formiate de métal alcalin. L'invention concerne également un catalyseur d'hydrogénation, l'utilisation du catalyseur d'hydrogénation pour produire des sels hydroxyles d'ammonium, des procédés de préparation de sels hydroxyles d'ammonium et un procédé de régénération de catalyseurs d'hydrogénation contenant du platine.
EP96933397A 1995-10-04 1996-09-26 Procede de preparation d'un catalyseur d'hydrogenation Withdrawn EP0862494A1 (fr)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
DE19536777A DE19536777C1 (de) 1995-10-04 1995-10-04 Verfahren zur Herstellung eines Hydrierungskatalysators und seine Verwendung
DE19536777 1995-10-04
PCT/EP1996/004203 WO1997012673A1 (fr) 1995-10-04 1996-09-26 Procede de preparation d'un catalyseur d'hydrogenation

Publications (1)

Publication Number Publication Date
EP0862494A1 true EP0862494A1 (fr) 1998-09-09

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Family Applications (1)

Application Number Title Priority Date Filing Date
EP96933397A Withdrawn EP0862494A1 (fr) 1995-10-04 1996-09-26 Procede de preparation d'un catalyseur d'hydrogenation

Country Status (6)

Country Link
EP (1) EP0862494A1 (fr)
JP (1) JPH11513302A (fr)
CN (1) CN1198686A (fr)
CA (1) CA2231536A1 (fr)
DE (1) DE19536777C1 (fr)
WO (1) WO1997012673A1 (fr)

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2006080326A1 (fr) * 2005-01-25 2006-08-03 Ajinomoto Co., Inc. Procédé servant à produire un dérivé de nucléoside

Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1088037B (de) * 1957-10-23 1960-09-01 Basf Ag Verfahren zur Herstellung und Regenerierung eines Spezial-katalysators fuer die Gewinnung von Hydroxylamin
CH395038A (de) * 1960-03-11 1965-07-15 Basf Ag Verfahren zur Herstellung von Platin-Träger-Katalysatoren für die Synthese von Hydroxylamin aus Stickoxyd und Wasserstoff
DE3713733A1 (de) * 1987-04-24 1988-11-17 Basf Ag Verfahren zur herstellung von hydroxylammoniumsalzen
DE4311420A1 (de) * 1993-04-07 1994-10-13 Basf Ag Hydrierungskatalysator auf der Basis eines mit feinteiligem Schwefel partiell vergifteten Platinmetalls
DE19502580A1 (de) * 1995-01-27 1996-08-01 Basf Ag Verfahren zur Herstellung eines Hydrierungskatalysators

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See references of WO9712673A1 *

Also Published As

Publication number Publication date
WO1997012673A1 (fr) 1997-04-10
CA2231536A1 (fr) 1997-04-10
DE19536777C1 (de) 1997-05-15
CN1198686A (zh) 1998-11-11
MX9802151A (es) 1998-08-30
JPH11513302A (ja) 1999-11-16

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