DE1965072C3 - Process for the preparation of silica-supported nickel catalysts - Google Patents

Description

2. The method according to claim 1, characterized gekenn- ™ method, the solution of the nickel compound must be characterized by boiling the organic base in a very long time with urea (see. Inorganic solvent that dissolves in the water game V, cooking time of 44 Hours). The long salt solution is essentially insoluble. Cooking at a higher pH value will seriously attack the support and under the reaction conditions used, as a result of which the properties of the catalyst will not react with the salt solution. * 5 shafts can be reduced.

3. Use of a according to claim 1 or 2 In another method, the nickel is aiff Manufactured nickel-supported catalyst for the catalyst support material by boiling a suspension table hydrogenation of fatty alcohols, fatty acids of this material in a solution of nickel in and fatty acid esters, in particular triglycerides, precipitated ammonia, with ammonia under free one or more double bonds. 30 Settlement of nickel ions develops and the nickel

as hydroxide in the form of fine particles over the entire surface of the carrier material inclusive

the inner surface is precipitated. However, points

this method has the disadvantage that it is

35 materials that are sensitive to alkali,

for example silicon dioxide, is less suitable,

The invention relates to a method for, since the surface thereof is influenced under the strong production of nickel catalysts with a SiIi-basic conditions.
cium dioxide carrier. The object of the invention is to provide a

Nickel catalysts with a silicon dioxide-Trä- 4 ° process, through which while avoiding the ger have been known in the art for many years. disadvantages of the known They are used in numerous hydrogenation reactions. and their use in the catalytic dioxide carrier can be produced in a simple manner Hydrogenation of fatty products, such as fatty alcohols, in which the important catalysts take their own, Fatty acids and fatty acid esters, especially 45, such as activity, resistance to catalysis triglycerides with one or more double binder poisons, resistance to sintering, selectivity fertilizing is particularly important. It has been recognized and advantageously demonstrated good filterability the effectiveness of such catalysts are agreed by one.

Number of different properties, such as B. The method according to the invention for the production

Activity, resistance to poison, resistance of nickel catalysts with a silicon opposite Sintering and selectivity depends. dioxide carrier, the nickel with an organic

If the catalyst is to have a high activity in the base of an aqueous nickel salt solution, it is desirable that the catalyst contains a large form of nickel hydroxide on a specific metal surface in the solution (surface area per weight suspended carrier, the silicon dioxide with a unit of the catalyst ) which has the reaction specific surface area in the range of 5 to 750 m ² / g components is easily accessible. That is the case, contains, is precipitated, whereupon the solid material, when the catalytic agent is separated evenly over the desired entire surfaces of the support material separated from the aqueous solution, is washed, dried and then activated in the form of very fine particles or as a thin layer , is characterized in that the nickel is dispersed. ßo hydroxyd with an insoluble in the nickel salt solution

A large number of working organic bases are in the literature in at least stoichiometric amounts for the production of nickel carrier catalytic ratio to the nickel salt under vigorous sators described. mechanical mixing is precipitated.

Dic-e methods are all based on a gradual It has been found that those according to the invention

Increase in the pH of a suspension of the support ⁶ 5 prepared nickel catalysts on a silicon in a solution of a nickel salt. The increase in the dioxide carrier has various advantages over the pH value is mostly caused by the addition of alkali, catalysts that are produced with the help of such as NaOH and / or Na ₂ CO ₃ . Known in the art, explained in the foregoing

3 4

Precipitation reactions were produced. Without being with the solid precipitation remains, so that in the limitation to any theory is assumed. Separation of the solid substance from the reaction mixture Difficulties arise due to the following fundamental differences. This difficult between the precipitation reaction in the process can in general by the addition according to the invention and in the case of the known examples of an organic solvent to which reaction precipitates can be explained. With the known mixture before or after the precipitation reaction Procedures an aqueous solution of an alkali will be dissolved or reduced. Suitable organic lisch reacting product, z. B. of alkali hydroxide solvents are e.g. benzene, toluene, hexane, oier carbonate, the aqueous solution of the nickel salt, petroleum ether, kerosene, ether. Diisopropyl ether. Tetra added. Even when stirring in very effective io chlorocarbon, chloroform or methylene chloride. If it takes place in a manner which leads to the formation of a localized structure, chloroform produces particularly good results high concentration of hydroxyl ions at the nits.

Place in which the alkaline solution contains the salt

solution touched. As a result, nickel hydroxide will cause nickel hydroxide to be the ratio of

or another insoluble nickel compound of an organic base at least equal to the nickel salt

noticeably failed, regardless of whether in the stoichiometric ratio, but im

Sew a support material or not. general the use of an excess of the

This implies that at least part of the insoluble base is preferred.

Nickel compound not at all on the carrier material can be precipitated in the process and / or that the precipitated nickel compound can not be homogeneous over the carrier material which is sufficiently soluble in water. Is distributed at the surface. In contrast, the games for such salts are nickel chloride, nickel pH value of the salt solution in the process according to nitrate, nici.elacctat and nickel sulfate,
The invention is gradually increased in an identical manner for the execution of the process according to the Erling entire solution while avoiding the formation of dung on an industrial scale, due to local high hydroxyl ion concentrations, economic considerations increase the size of the solution. Accordingly, the insoluble nickel is also preferably used.

hydroxide is formed only gradually, which leads to a

more rapid precipitation of the same on the particles of the hydrogenation of triglycerides are provided, which

Carrier material, which act as crystallization nuclei, derived from polyunsaturated fatty acids

than exist for the formation of new crystal nuclei, a silica with such

from the nickel hydroxide itself. In addition, a porcelain structure is sufficient, in which a significant part of the

even a brief stirring at room temperature. Pores with a diameter of more than 25 A, preferably

Which in the method according to the invention to wise more than 80 A possesses. bc \ <n / ugt.
The organic bases used should be so strong that the precipitation reaction can be at temperatures that sufficient hydrogen ions in the range between the temperature at which are withdrawn from the aqueous salt solution to all the reaction components either in a liquid or dissolved therein for the precipitation of the nickel hydroxide State (usually required pH value to be maintained. Preferably OC or a few degrees lower) and the boiling point primary or secondary alkylamines are used, 4 ° point of the lowest-boiling component whose alkyl groups in total at least 8 and (aqueous solution or organic solvent) preferably 10 to 22 carbon atoms. are executed. Surprisingly, examples of such wet nurses are n-octylamine, which, in contrast to most of the known n-dodecylamine or n-octadecylamine. The working methods described above in particular, in which good results are obtained when using mixtures 45, the precipitation reaction is preferably obtained at a temperature of tert-alkylamines which is commercially available from 90 to 100 ° C. and the tertiary alkyl groups thereof are 12 to Processes according to the invention also very well comprise at 14 and 18 to 22 carbon atoms, respectively. lower temperatures, e.g. B. 10 to 50 C, preferably

More examples of organic bases that can be run wisely at room temperature, expedient in the method according to the invention 50. This is associated with various advantages can be used are alkyl diamines, e.g. B. First, the surface of the substrate is at Λ, ω-nonyl diamine and Λ, ω-dodecyl diamine. on the other hand, the same pH conditions of the alka-'where appropriate The organic base can also be used in substantially dissolved form at this temperature, although this has less of an effect than the normal solvent in the aqueous salt solution also 55 turned high temperature. This means that should be essentially insoluble and with this one is a much better one: control or regulation under the applied reaction- the specific surface of the finally obtained conditions should not react. The use of a catalyst has, since this surface is now Such a solvent is particularly important not to change during the precipitation process and if the organic base used is the case, therefore, it depends only on the choice of starting material applied reaction temperature is solid. is dependent. A second benefit of the application

Occasionally, depending on such a low temperature, it may then exist that,

Factors such as the type of nickel salt, the concentration when the precipitation of nickel hydroxide on silicon

tration of salt solution, the type of organic base ciumdioxyd at relatively high temperatures

and the reaction temperature, if 65 occurs, this silica is among those used

the organic base after completion of the precipitation conditions with the filled in Nickclhydroxyci

reaction suspended or even cmulgicit in the can react. The connections formed in the process

aqueous solution completely or partially together can result in a subsequent reduction of the nickel

α μ, it can be seen that the invention therefore also extends to the ί

inhibit connection to metallic nickel, vvodurcn TJ "' _{refers to these} non-activated masses!

a reduced degree of reduction and, as a result, π _Ve ^ _{drive like} according to the invention is after- ■

decreased activity is obtained. Explained in _more detail for _{applications.} !

dung of higher reduction temperatures may stenenu _Λ,

in these cases the degree of reduction actually increases 5 B e ι s ρ ι e 1 1 ':

be, however, in this way also the suspension of 25 g of a spherical

Risk of sintering is increased. With off. Silica with a specific

conduct the precipitation at lower temperatures, if ^ ^ ^ ^ ^ ^ ^ ^. ". ^

For example, at room temperature, a change occurs _{with stirring} successively

effect between the carrier material and the io Was ** nickel nitrate (Ni (NO ₃ ), 6H ₂ O)

precipitated nickel compound to a lesser extent ^ε ' ^ηε Α ° *, gj ^ _M - _sch j JI

a _R This is shown very clearly from the fact m 100 JIJa ^ ^ ^ ₂₂ ^^ f ^;

_{that the suspension obtained} during the reduction at this temperature was 30 minutes

The mass produced is vigorously stirred _{at a temperature of q} ed.glch jWjn ^ _{room temperature.} then

300-C, a reduction rate of 10 U orld ore 15 th long _{petroleum train} e _give n, and the!

is, while with the compositions according burned ™ _{rfe for about} 15 minutes stand- j

Arbe.tswe.sen produced '™ ^ «* ** 2 * ¹ Jj XL _n After filtering off the filter cake

A temperature of around 450 to 500 C is required. " _Petro] ether washed and vacuumed

and the degree of reduction even then often * · ^ ™ ° "™ _{rnrkliet wobe} j mass mi 'a

hetradHüch stays below 100% for the achievement of * o ^^^^^ J ^^ _A ^ \

of such a high degree of reduction iste ^ "Nuel SÄ composition was prepared by the same reduction

influencing the mass by persistent ration ^ ^ ^^ _tubular ^

Water to be combined during the drying process if a hydrogen flow is required

Therefore, in this case, drying should be carried out at tempera- <ou <- ^U11U _r nickel errvi, -tit

doors that are as low as possible take place, where * 5 extent of 36 1 / hour. per gram of N.ckel erruüu.

it is preferred to use as much of the adhered Example 2 as possible

Water before heating, for example by washing "_c; _n ",""? s ο rinp« lnwlfs ™; »

for intimate mixing of mutually insoluble tertiary alkylamines having 18 to 22 carbon atoms

Liquids and solids with liquids added. The suspension obtained was during

can be achieved. Examples of suitable 30 minutes vigorously stirred at room temperature,

mechanical working methods are stirring. Shaking Then 150 ml of petroleum ether were added, and d.e

or bubbling with air or other gases. The mixture was left to stand for about 15 minutes.

Be, the method according to the invention is left. After filtration, the filter cake became

Mixing process, e.g. B. Stir, preferably so vigorously 4 »washed repeatedly with petroleum ether and during

stated that both the carrier material! as well as 16 hours at 200 ⁰ C dried with a mass

the organic base was dispersed in the aqueous solution with a nickel content of 18.9 ^,

be greeted. This state is preferably due to- The activation of this mass has been made by reducing

until the nickel hydroxide is precipitated for 4 hours in a tubular

on the carrier material as completely as possible caused 45 oven at 450 ⁰ C in a hydrogen stream at a

is. and this can be done in a simple manner by a rate of 36 1 / hour. achieved per gram of nickel,

quantitative or qualitative determination of the in an example 3

Sample of the aqueous solution still present,

Nickel ions are tested. To a suspension of 25 g of a macroporous

The mass obtained is made up of the reaction silica with a specific surface area of

medium separated, washed with water and 320 m ² / g in 400 ml of distilled water were under

if desired with an organic solution stirring successively a solution of 37.5 g

medium such as acetone or ethanol, washed, then nickel nitrate (Ni (NOa) ₂ · 6H ₂ O) in 100 ml of water

ßend dried and, if necessary, ground. and 150 ml of a mixture of tertiary alkyl amines

The mass thus obtained is then added at a temperature with 18 to 22 carbon atoms. The received

temperature from 120 to 800 ⁰ C, preferably from 300 to ten suspension was for 30 minutes at

500 ^c C. reduced with the help of hydrogen gas, stirred vigorously to room temperature. Then 150 ml

the active nickel-on-silica catalyst was added to acetone and the mixture was stirred during

obtained in which the nickel was allowed to stand in finely divided about 15 minutes. After filtration

metallic form is present. 60 the filter cake was repeatedly washed with acetone

The quality of the catalysts thus obtained is seen and dried in vacuo at 20 ° C, whereby

usually deteriorated rapidly on storage, and a mass obtained with a nickel content of 18.0%

they have very frequent pyrophoric properties. Became out. The specific surface area of the

for this reason the catalysts for example dried cake was 350 m ² / g. The activation

wise for storage or with a view to selling 6 ₅ this mass has been reduced by during a

in the form of a non-activated mass. Hour in a tubular oven at 400 ⁰ C and

and this mass undergoes an activation treatment in a hydrogen stream to the extent of

only subjected immediately before use. It has reached 361 / hour / g nickel. The specific surface

of the catalyst was 310 m ² / g. The pore size of the silica at the various stages of the process was as follows:

Macroporous silica> 95% 50 to 130 A.

Dried cake> 95% ... 50 to 120 A Activated catalyst > 95% .. 50 to 120 A

The pore size distribution curves for the macroporous Silica and the activated catalyst show that within experimental error none Change in pore size distribution occurred.

Example 4

_{A solution of 137.2 g of nickel nitrate (Ni (NO 3} ) J-OHaO) in 200 ml of water was added one after the other to a suspension of 25 g of a macroporous silicon dioxide with a specific surface area of 292 m * / g in 500 ml of distilled water and 450 ml of a mixture of tertiary alkyl amines having 18 to 22 carbon atoms were added. The suspension obtained was stirred vigorously for 30 minutes at room temperature. Then 150 ml of acetone was added and the mixture was allowed to stand for about 15 minutes.

After filtration, the filter cake was washed repeatedly with acetone and dried in vacuo at 20 ° C., a mass with a nickel content of 30.6% being obtained. The activation of this mass was achieved by reducing it for one hour in a tubular furnace at 400 ^° C. and in a stream of hydrogen at a rate of 36 l / h / g nickel.
5

Example 5

To a suspension of 25 g of a microporous silicon dioxide with a specific surface area of 527 m ² / g in 400 ml of distilled water were divided

ι »Stir successively a solution of 37.5 g of nickel nitrate (Ni (NOa) ₂ -OH ₁ O) in 100 ml of water and 150 ml of a mixture of tert-alkylamines with 18 to 22 carbon atoms. The suspension obtained was for 30 minutes:

Vigorously stirred at room temperature. Then, 150 m of acetone were added, and the mixture was allowed to stand währenc about 15 minutes. After filter feeders, the filter cake was repeated with acetone see gewä and C ^c in vacuo at 20 dried wöbe a composition having a nickel content of 12.7% was preserver. The activation of this reducing composition was durcl for one hour in a rohrför-shaped furnace at 300 ⁰ C and in a hydrogen stream at a rate of 36 l / hr. / G nickel

as achieved.

The properties of the various catalysts or optionally the compositions from which they were obtained are set out below Table listed. These properties were all determined using standard methods.

properties Catalysts
1 2 18.9 3 18.0 4th 30.6 5 12.7 Percent "atz nickel 16.5 412 251 144 294 Specific surface area
irr / g catalyst ") 119 685 325 231 453 Specific surface area
m ² / g silicon dioxide ") 214 57.7 *) 96.3 ") 100.0 ") 100.0? Degree of reduction 75.4 ") 191 187 184 247 Specific Ni surface area
m ² / g Ni-total ^c ) 219 36.1 33.9 56.3 31.4 Ni surface area
m ² / g catalyst ¹ ) 36.1 78% 118% - - Activity (sesame oil) (A, 180) - 67% 36% - - Nickel consumption - 65 20 ") - - Selectivity D ₃₀ - 2.02 3.67 - - Benzene activity - Notes on the table:
a) Reduced at 450 ° C.
V) Reduced at 400 ^° C
ε) Reduced at 300 ° C.
<i) Unreduced mass,
e) Reduced mass.

Example 6

To a suspension of 25 g of a spherical amorphous Siliciumdioxyds having a specific surface of 200 m * / g in 400 ml of distilled water with stirring, a solution of 37.5 g of nickel nitrate (Ni (NOA) -OHjO ₁₎ in 100 ml of water and 150 ml of a mixture of tert-alkylamines with 18 to 22 carbon atoms in ISO ml of kerosene (boiling point 60 to 90 ° C.) were added. The suspension obtained was stirred vigorously for 30 minutes at room temperature, and the mixture was left to stand for about 15 minutes After filtering, the filter cake was again

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washed with Pctroläther in vacuo at 20 ⁰ C dried, whereby a composition was obtained with a Nickclgehalt of about 17.5%. The reduction of this mass at 400 ° C. in a stream of hydrogen gave a nickel-on-silicon dioxide catalyst with approximately the same properties as the catalyst obtained in Example 3.

Example 7

To a suspension of 20 g of a spherical amorphous Siliciumdioxyds having a specific surface area of 200 m ² / g in 250 ml of distilled water, a solution of 30 g nickel nitrate (Ni (NO _3)? · 6H ₂ O) were successively added with stirring in 300 ml Water and 22 g of Λ, ω-nonyldiamine in 250 ml of chloroform. The resulting suspension was vigorously stirred for 30 minutes at room temperature and the mixture was allowed to stand for about 15 minutes. After filtration, the filter cake was repeatedly with chloroform and then washed with acetone and dried in vacuo at 20 ³ C, whereby a composition was obtained which was reduced in a hydrogen stream at 400 ⁰ C, with a nickel-on-silica catalyst obtained would.

Equally good results were obtained using α, ω-dodecyldiamine, dioctadecylamine, n-Undecylamine and n-Octylamine, with partially was also worked with benzene as a solvent.

Example 8

The experiment described in Example 1 was repeated with the modification that the mixture was stirred at a temperature of 50 ⁰ C. After cooling the solid material was filtered off, repeatedly washed with acetone and dried at 2O ⁰ C, whereby a composition was obtained, could be the current in a hydrogen at 300 ⁰ C quantitatively to a nickel on silica catalyst is reduced, which is about the same properties as the catalyst prepared in Example 1 possessed.

B e i s ρ i c 1 9

To a suspension of 20 g of a spherical amorphous Siliciumdioxyds having a specific surface area of 200 m ^z / g in a solution of 27 g of nickel sulfate (NiSO ₄ OH ₂ O) in 600 ml of water were

ίο 100 ml of a mixture of tert-alkylamines with 12 to 14 carbon atoms are added with stirring. The resulting mixture was stirred vigorously at room temperature for about 15 minutes, and the mixture was allowed to stand for about 15 minutes. After filtering, the filter cake was first washed repeatedly with water until no more sulfate ions could be found in the washing water. Thereafter, the filter cake was washed with acetone and dried in vacuum at 2O ⁰ C, whereby a composition was obtained having a nickel content of about 18.1%. This mass could be quantitatively reduced in a stream of hydrogen at 300 ⁰ C.

* 5 At s ρ i el 10

(Comparative example)

This example corresponds to example V of NL-PS 67 05 259. 102 g of Ni (NO ₃ ) ₂ -6H ₂ O, 49 g of NaNO ₂ , 43 g of urea and 20 g of silicon dioxide were added to 41 water. ^{The suspension was heated to 88 °} C. for 44 hours with vigorous stirring, after which it was filtered through a glass filter. The mass was washed with distilled water, followed by drying at 120 ° C. for 84 hours. A catalyst with a nickel content of 39.2%, which was reduced at 500 ° C., was obtained. The catalyst obtained in this way showed a sesame activity of only 40%.

• -3 * -ν -.-

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Claims (1)

One part of these known processes is that local patent claims · Overconcentrations of the alkali can hardly be avoided. This causes some of the nickel hydroxide to settle 1. Process for the production of nickel catalysts does not depend on the support, but is in the solution with a Sii.ciumdioxyd support, where 5 is precipitated. In addition, the main part of the nickel is precipitated with an organic base from a hydroxide on the outer surface of the support aqueous nickel salt solution in the form of nickel, and only a small part is deposited on the hydroxide on an inner surface of the support pores suspended in the solution. Another carrier, the silica with a specific disadvantage is that during the precipitation the carrier surface contains in the range of 5 to 750 m ² / g,> o the influence of the hot alkaline solution is precipitated, whereupon the solid material from the is exposed, which is separated when using Sihciumaqueous solution, if desired, dissolved dioxide as a carrier material to deteriorate washed, dried and then activated leads to the surface structure. is, thereby geke nn zeic h η e t that from NL patent application 67 05 239 it is the nickel hydroxide with one known in the nickel salt 15, a gradual increase in pH solution insoluble organic base in at least one hydroxyl ion by means of decomposition stoichiometric ratio to the nickel salt compound, such as urea induce. Through Precipitated with vigorous mechanical mixing this measure will be local overconcentration. alkali tation is prevented, but with this