JP2012510355A - Catalyst carrier, method for producing the same, and use thereof - Google Patents

Abstract

The present invention is an open-pored catalyst support comprising a material containing natural layered silicate, having an acidity of 10 μval to 60 μval, an average pore diameter of 10.5 nm to 14 nm, and a specific surface area of 160 m. ² / g to 175 m ² / g, a bulk density of 480 g / l to 550 g / l, an Al ₂ O ₃ content of less than 2.5% by weight, and a water absorption of more than 65% The present invention relates to a carrier, a process for its production and its use.
[Selection figure] None

Description

  The present invention relates to an open-pored catalyst support, a process for its production, and its use.

Vinyl acetate monomer (VAM) is an important monomer that assembles blocks in the synthesis of plastic polymers.
The main fields of use of VAM are in particular polyvinyl acetate, polyvinyl alcohol, and polyvinyl acetal, and other monomers such as ethylene, vinyl chloride, acrylate, maleate, fumarate and vinyl laurate, etc. And the production of terpolymers.

VAM is mainly generated in the gas phase from acetic acid and ethylene by an oxidation reaction, where the catalyst used for this synthesis is preferably Pd as the active metal, Au as the promoter, It contains an alkali metal component as a co-promoter, more preferably potassium in the form of acetate.
In these catalytic Pd / Au systems, the presence of non-alloyed particles cannot be ruled out, but the metals of Pd and Au are not in the form of metal particles of their respective pure metals, but rather Pd / Au alloys of different configurations. Present in the form of particles.
As an alternative to Au, for example, Cd or Ba can be used as a copromoter.

In recent years, VAM is mainly produced using a so-called shell catalyst, but the precious metals Pd and Au do not completely penetrate into the catalyst support formed as a molded body, but rather, Contained only in the area (shell) of the molded body, which is more or less outside (see EP 565 952 A1, EP 634 214 A1, EP 634 209 A1 and EP 634 208 A1), on the other hand, the catalyst support further inside There are no precious metals in this area.
By using a shell catalyst, more selective reaction control is possible in many cases than when using a catalyst in the support (impregnated through) in which the active component is permeated into the core of the support. It becomes.

Shell catalysts known in the prior art for producing VAM are, for example, catalyst supports based on silicon oxide, aluminum oxide, aluminosilicate, titanium oxide or zirconium oxide (EP 839 793 A1, WO 1998). / 018553 A1, see WO 2000/058008 A1 and WO 2005/061107 A1).
At present, however, catalyst supports based on titanium oxide or zirconium oxide are rarely used because they do not exhibit long-term stability and are relatively expensive compared to acetic acid. Because there is.

  Most of the catalysts currently used to produce VAM are based on porous amorphous aluminosilicate supports formed as spheres based on natural layered silicate fully impregnated with potassium acetate as a co-promoter. A shell catalyst having a shell of Pd / Au.

  Such VAMs are usually produced by a so-called chemical route in which the catalyst support is immersed in a solution of the corresponding metal precursor compound, for example by immersing the support in the solution, or when the support is finely divided. Produced by an initial wetting method (pore filling method) loaded with an amount of solution corresponding to the pore volume.

For example, the Pd / Au shell of the catalyst may be prepared by first immersing the catalyst carrier in a Na ₂ PdCl ₄ solution in the first step, and then using NaOH in the second step to form a Pd component in the form of a lead hydroxide compound in the catalyst carrier. It is generated by fixing.
Then, in another third step, the catalyst support is immersed in a NaAuCl ₄ solution and the Au component is similarly fixed by NaOH.
After fixing the noble metal component to the outer shell of the catalyst support, the support is washed thoroughly free of chlorine and Na ions, dried, calcined and finally reduced with ethylene at 150 ° C.
The Pd / Au shell thus produced usually has a thickness of about 100 μm to 500 μm.

Usually, the catalyst support loaded with the noble metal is loaded with potassium acetate after the last fixing or reducing step, but here the loading of potassium acetate is performed only on the outer shell loaded with the noble metal. The catalyst support is completely impregnated with the copromoter.
A spherical support called “KA-160” from Sued Chemie AG (Munich, Germany) based on natural layered silicates has a BET surface area of about 160 m ² / g, but is mainly used as a catalyst support. .

The VAM shell catalyst known in the prior art based on Pd and Au, and the VAM selectivity achieved by the KA-160 support is about 90 mol%, based on the supplied ethylene, where: The remaining 10 mol% of the reaction product is basically CO ₂ produced by total oxidation of the organic educt / product.
Thus, further increases in VAM selectivity or suppression of total oxidation can minimize starting material loss, reduce so-called “hot spots” in the reaction tube, thereby extending the life of the VAM catalyst, and recycling. Required to mitigate CO ₂ purge with gas.

  Accordingly, it is an object of the present invention to provide a catalyst support capable of producing a VAM catalyst characterized by a relatively high VAM selectivity.

The object is an open pore catalyst support comprising a material containing natural layered silicate, having an acidity of 10 μval to 60 μval, an average pore diameter of 10.5 nm to 14 nm, and a specific surface area of 160 m ² / g. Reached by a catalyst support with a bulk density of 175 m ² / g, a bulk density of 480 g / l to 550 g / l, an Al ₂ O ₃ content of less than 2.5% by weight and a water absorption of more than 65% .

Surprisingly, by using an open pore catalyst support having the above values according to the present invention for acidity, average pore diameter, specific surface area, bulk density, Al ₂ O ₃ content and water absorption as described above, Compared with a VAM catalyst produced using a conventional open pore catalyst support having no specific combination value, a VAM catalyst characterized by high selectivity and suppression of total oxidation can be produced. Was found.

The natural layered silicate is included in the catalyst carrier according to the present invention.
“Natural layered silicate” is also used in the literature instead of “phyllosilicate”, but within the framework of the invention, an SiO ₄ tetrahedron with a structure based on all silicate units Means an untreated or treated silicate material which is internally cross-linked in a layer of the general formula [Si ₂ O ₅ ] ²⁻ .
These tetrahedral sheets contain cations, mainly Al and Mg, and alternate with so-called octahedral sheets that are octahedrally coordinated surrounded by OH or O.
For example, a distinction is made between two-layer phyllosilicates and three-layer phyllosilicates.
Layered silicates are preferably clay minerals within the framework of the invention, in particular kaolinite, beidellite, hectorite, saponite, nontronite, mica, vermiculite and smectite, among others Smectite and especially montmorillonite are preferred.
The definition of the term “Schichtsilikate” is, for example, “Lehrbuch der anorganischen Chemie” Hollemann Wiberg, de Gruyter, 102 ^nd edition, 2007 (ISBN 978-3-11-017770-1) or “ Rompp Lexikon Chemie (“Rompp” “o” is umlaut) ”, found in the“ Phyllosilikat ”section of Georg Thieme Verlag.

  Typical treatments for natural layered silicates prior to use as a support material include, for example, treatment with acids, in particular mineral acids such as hydrochloric acid and / or calcination.

The catalyst carrier according to the present invention has an acidity of 10 μval / g to 60 μval / g.
The level of acidity of the catalyst support according to the invention can advantageously affect the activity of the corresponding catalyst for the gas phase synthesis of VAM from acetic acid and ethene.
In a more preferred embodiment of the catalyst according to the present invention, the catalyst carrier has an acidity of 20 μval / g to 60 μval / g.
The acidity of the carrier can be increased, for example, by impregnating the carrier with an acid.

The acidity of the catalyst support is measured as follows.
100 mL of water (having a pH blank value) is added to 1 g of finely crushed catalyst support and extraction is carried out for 15 minutes while stirring.
Titration to at least pH 7.0 with 0.01 N NaOH solution is performed as follows: first, 1 mL of NaOH solution is applied to the extract (1 drop / second), wait 2 minutes, pH Here, titration is performed stepwise, for example, 1 mL of NaOH solution is added dropwise.
The blank value of the water used is measured and the calculation of the degree of oxidation is corrected.
Then, a titration curve (amount of 0.01 N NaOH with respect to pH, mL) is plotted, and the intersection point of the titration curve at pH 7 is determined.
The molar equivalent obtained from the consumption of NaOH up to the intersection of pH 7 is calculated as 10 ⁻⁶ equiv / g per carrier.

The catalyst carrier according to the present invention has an average pore diameter of 10.5 nm to 14 nm.
In order to keep the pore diffusion limit of the catalyst support according to the present invention to a minimum, as a further preferred embodiment of the catalyst support according to the present invention, an average pore diameter of 10.5 nm to 12 nm is provided.
The average pore size is measured according to DIN 66134 (measurement of pore size distribution and specific surface area of mesoporous solids by nitrogen adsorption method using N2 adsorption isotherm (BJH method (Barrett, Joyner and Halenda method)).

The specific surface area of the catalyst support according to the present invention is from 160 m ² / g to 175 m ² / g, preferably from 165 m ² / g to 170 m ² / g.
The VAM selectivity of the VAM catalyst produced using the catalyst carrier according to the present invention and the suppression of total oxidation can be achieved when the specific surface area of the catalyst carrier according to the present invention is in the above range. In most of the activity of this is higher than with conventionally produced VAM catalysts.
The specific surface area is measured according to DIN 66131 (measurement of the specific surface area of a solid by gas adsorption according to the BET method (Brunauer, Emmett and Teller method)) and DIN 66132 using nitrogen.

  The bulk density (compression density) of the catalyst carrier according to the present invention is 480 g / l to 550 g / l, preferably 480 g / l to 520 g / l.

In the catalyst support according to the present invention, the natural layered silicate contains less than 2.5% by weight of Al ₂ O _{3 based} on the weight of the natural layered silicate contained in the catalyst support according to the present invention, preferably Contains 0.1% to 2.0% by weight, more preferably 0.3% to 1.8% by weight of Al ₂ O ₃ .
The Al ₂ O ₃ content of the natural layered silicate is constrained to a relatively low value according to the present invention, which is a high Al ₂ O in the gas phase synthesis of VAM from acetic acid and ethene. _This is because a significant decrease in the indentation hardness should be expected at the ₃ content, whereas the relatively low Al ₂ O ₃ content in the natural layered silicate is hardly detrimental.

The water absorption calculated according to the weight increase due to water absorption of the catalyst support according to the present invention is more than 65%, preferably 66% to 80%, more preferably 67% to 75%.
The water absorption is measured by immersing a 10 g carrier sample in deionized water for 30 minutes until no gas bubbles emerge from the carrier sample.
Excess water is removed and the sample is wiped off to remove any water attached with a cotton towel.
And the support | carrier containing a water | moisture content is measured for a weight, and a water absorption is computed by the following formula | equation.

(Out total weight (g) −In total weight (g)) × 10 = Water absorption (%)

Natural layered silicates are particularly preferably used within the framework of the present invention, montmorillonite, preferably in the form of bentonite.
Bentonite is a mixture of different clay minerals containing montmorillonite (about 50% to 90% by weight) as the main constituent.
Furthermore, accompanying materials may include quartz, mica and feldspar, among others.

  According to a further preferred embodiment of the catalyst carrier according to the present invention, the natural layered silicate is an acid activated natural layered silicate.

Acid-activated layered silicates are known in the prior art (Rompp Lexikon Chemie, 10 ^th edition (“Rompp” “o” is umlaut), Georg Thieme Verlag, “Bentonite”).
In order to increase the adsorptive power of the catalyst support according to the present invention, the natural layered silicate is preferably present in the support on the acid activated natural layered silicate.
More preferably, the acid activated natural layered silicate is acid activated montmorillonite.
According to the present invention, the montmorillonite is more preferably in the form of acid-activated bentonite contained in the carrier according to the present invention.

According to a further preferred embodiment of the catalyst carrier according to the invention, it is provided that the catalyst carrier has a hardness of more than 60N, preferably 62N to 80N, more preferably 65N to 75N. Is done.
The hardness (press-fit hardness) is the same as that of Dr. It is measured on a spherical probe (diameter: 5 mm) using a table hardness meter 8M manufactured by Schleuniger Pharmatron AG (Switzerland).
Prior to measurement, the sample is dried for 2 hours at 130 ° C.
The hardness is calculated from the average of 99 measurements.
Selectable parameters of the table hardness meter 8M for measurement are set as follows.
Hardness (dimension): N
Distance from sample: 5.00mm
Time delay: 0.80 seconds Feed type: 6D
Speed: 0.60mm / s

  According to the invention, the proportion of natural layered silicate in the catalyst support according to the invention is at least 50% by weight, preferably 55% to 100% by weight, preferably 60% by weight, based on the weight of the catalyst support. % To 99% by weight, more preferably 65% to 98% by weight, and even more preferably 70% to 97% by weight.

  In a further preferred embodiment of the catalyst carrier according to the present invention, it is provided that the catalyst carrier has a total pore volume of 0.25 mL / g to 0.8 mL / g.

It has been found that the VAM selectivity of a VAM catalyst produced using the catalyst support according to the present invention depends on the total pore volume of the catalyst support.
The total pore volume of the catalyst support is 0.25 ml / g to 0.8 ml / g, preferably 0.4 ml / g to 0.75 ml / g and preferably 0.5 ml / g to 0.7 ml / g. is there.
The total pore volume is measured by DIN 66134 (nitrogen adsorption method (BJH method (Barrett, Joyner and Halenda method)).

According to a further preferred embodiment of the catalyst support according to the invention, it is provided that at least 80%, preferably 90%, more preferably 95% of the total pore volume of the catalyst support is formed from mesoporous and microporous. Is done.
This is due to the VAM catalyst support produced with the catalyst support produced according to the invention, in particular affected by the diffusion limit, in particular with the relatively thick shelled Pd / Au shell catalyst support produced according to the invention. , Neutralize the suppression of activity.
“Microporous”, “mesoporous” and “macroporous” mean having pores with a diameter of less than 2 nm, a diameter of 2 to 50 nm and a diameter of more than 50 nm, respectively.
The proportion of mesoporous and macroporous in the total pore volume is measured by DIN 66134 DIN 66134 (measurement of pore size distribution and specific surface area of mesoporous solids by nitrogen adsorption method (BJH method (Barrett, Joyner and Halenda method)) It is measured using the pore size distribution of the catalyst support according to the above.

According to a further preferred embodiment of the catalyst support according to the invention, the SiO ₂ content of the natural layered silicate in the catalyst support is at least 65% by weight, preferably at least 80% by weight and particularly preferably 90% by weight. % To 98% by weight is provided.
Therefore, the high chemical resistance of the catalyst carrier according to the present invention is exhibited in the VAM synthesis.

  According to a further preferred embodiment of the catalyst carrier according to the invention, it is provided that the catalyst carrier is formed as a shaped body.

In particular, regarding the production of the shell catalyst, the catalyst carrier according to the present invention is preferably formed as a molded body.
In principle, the catalyst support can take any form known to those skilled in the art suitable for the purposes of the present invention.
For example, the catalyst carrier according to the present invention has a spherical shape, a cylindrical shape, a perforated cylindrical shape, a trefoil shape, an annular shape, a star shape, a torus shape, or a spiral shape, preferably a spiral shape with a rib or a star shape spiral shape. The shape can be taken.

  According to a further preferred embodiment of the catalyst carrier according to the invention, it is provided that the maximum size of the catalyst carrier is 1 mm to 25 mm, preferably the maximum size 3 mm to 15 mm.

  According to a further preferred embodiment of the catalyst carrier according to the present invention, it is provided that the catalyst carrier is formed into a sphere.

  According to a further preferred embodiment of the catalyst carrier according to the present invention, it is provided that the diameter of the sphere is 2 mm to 10 mm, preferably 4 mm to 8 mm.

According to a further preferred embodiment of the catalyst support according to the present invention, the catalyst support is at least one metal selected from the group consisting of Hf, Ti, Nb, Ta, W, Mg, Re, Y and Fe. It is provided that it is doped with an oxide.
The activity of the VAM catalyst produced using the catalyst carrier according to the present invention can be improved by doping.

According to a further preferred embodiment of the catalyst support according to the invention, the proportion of dopant oxide in the catalyst support is from 1% to 25% by weight, preferably from 3% to 15%, based on the weight of the catalyst support. It is provided that it is by weight, and more preferably 5-10%.
The doping can be performed, for example, by surface doping, as known from the prior art, or the one or more metal oxides can be incorporated into the matrix of the catalyst support.

According to a further preferred embodiment, it is provided that the catalyst support is free of ZrO ₂ .
“ZrO ₂ free” means that the ZrO ₂ content of the carrier is less than 200 ppm.

The invention is a process, in particular a process for the production of a catalyst support according to the invention,
The average pore size is less than 10.5 nm,
The specific surface area exceeds 175 m ² / g,
The bulk density exceeds 550 g / l,
Al ₂ O ₃ content exceeds 2.5% by weight, and water absorption exceeds 65%,
Supplying a first open pore catalyst support composed of a material containing natural layered silicate;
Also relevant is a process comprising treating the first catalyst support with a mineral acid to obtain a second catalyst support.

  A VAM catalyst which can be produced with a catalyst carrier produced using the method according to the invention is obtained, for example, using a conventional open pore catalyst carrier such as the first catalyst carrier used in the method according to the invention. It has been found that it is characterized by a relatively high selectivity compared to the VAM catalyst.

Any mineral acid known to those skilled in the art suitable for the purposes according to the invention can be used as the mineral acid.
Examples of preferred mineral acids are hydrochloric acid, nitric acid, sulfuric acid and phosphoric acid, among which hydrochloric acid, especially 20% hydrochloric acid is preferred.

Any ordinary open pore catalyst support that contains natural layered silicate as the first open pore catalyst support and satisfies the above average pore diameter, specific surface area, bulk density, Al ₂ O ₃ content and water absorption value But it can also be used.

  As an open pore catalyst support that can be used particularly preferably in the method according to the present invention, the first catalyst support is based on the product name “KA”, natural layered silicate, manufactured by Sud Chemie AG (Munich, Germany). There is a spherical carrier that matches the value of.

According to a preferred embodiment of the method according to the invention, the treatment of the first catalyst support with a mineral acid has an acidity of 10 μval to 60 μval, an average pore diameter of 10.5 nm to 14 nm, a specific surface area of 160 m ² / g. To 175 m ² / g, a bulk density of 480 g / l to 550 g / l, an Al ₂ O ₃ content of less than 2.5% by weight, and a second catalyst support with a water absorption of more than 65%. Can be provided.

  It can be noted that the description as described above for the more preferred embodiment of the open pore catalyst carrier according to the present invention is appropriately applied to the second open pore catalyst carrier that can be obtained by the method according to the present invention.

  According to a further preferred embodiment of the method according to the invention, the treatment with mineral acid is carried out over 5 to 100 hours, more preferably over 7 to 50 hours and in particular between 8 and 15 hours. Provided to be done over time.

  According to a further preferred embodiment of the method according to the invention, it is provided that the treatment with mineral acid is carried out at an elevated temperature, in particular at a temperature above 50 ° C.

  According to a further preferred embodiment of the method according to the invention, it is provided that after the treatment with mineral acid, the second catalyst support is washed.

  In the washing, the obtained second open pore catalyst support according to the present invention contains an acid residue after treatment with a mineral acid, optionally also a component dissolved from a natural layered silicate with a mineral acid. It serves to be free and such washing is preferably performed with water.

According to a further preferred embodiment of the method according to the invention, it is provided that the second catalyst support is calcined after washing.
The calcination is preferably performed at a temperature of 400 ° C. to 800 ° C., more preferably at a temperature of 500 ° C. to 700 ° C.
The calcination is carried out for 3 to 24 hours, preferably 5 to 20 hours, in particular 7 to 10 hours.

  According to a further preferred embodiment of the present invention, the natural layered silicate is montmorillonite, particularly preferably provided that montmorillonite is present as a constituent of bentonite.

  According to a further preferred embodiment of the catalyst carrier according to the present invention, it is provided that the natural layered silicate is an acid activated natural layered silicate.

According to the method of the present invention, it is provided that the specific surface area of the second catalyst support is from 165 m ² / g to 170 m ² / g.

  According to a further preferred embodiment of the method according to the invention, it is provided that the hardness of the second catalyst support exceeds 60N.

  According to a further preferred embodiment of the method according to the invention, it is provided that the acidity of the first catalyst support is from 1 μval / g to 80 μval / g.

  According to a further preferred embodiment of the method according to the invention, it is provided that the proportion of natural layered silicate in the first catalyst support is at least 50% by weight.

  According to a further preferred embodiment of the method according to the invention, it is provided that the total pore volume of the first catalyst support is from 0.25 ml / g to 0.8 ml / g.

  According to a further preferred embodiment of the method according to the invention, it is provided that at least 80% of the total pore volume of the catalyst support is formed from mesoporous and macroporous.

  According to a further preferred embodiment of the method according to the invention, it is provided that the bulk density of the second catalyst support is from 480 to 520 g / l.

According to a further preferred embodiment of the method according to the invention, it is provided that the SiO ₂ content of the natural layered silicate contained in the first catalyst support is at least 65% by weight.

  According to a further preferred embodiment of the method according to the invention, it is provided that the first catalyst support is formed as a shaped body, and the first catalyst support is preferably at most 1 mm to 25 mm. .

  According to a further preferred embodiment of the method according to the invention, it is provided that the first catalyst support is a sphere, and the diameter of the sphere is in particular from 2 mm to 10 mm.

  According to a further preferred embodiment of the method according to the present invention, the first catalyst support is at least one metal selected from the group consisting of Hf, Ti, Nb, Ta, W, Mg, Re, Y and Fe. It is provided that the proportion of dopant oxide in the first catalyst support is preferably 1% to 25% by weight.

According to a further preferred embodiment of the method according to the invention, it is provided that the first catalyst support is free of ZrO ₂ .

  The invention also relates to the catalyst support according to the invention obtainable by the method according to the invention.

  It also relates to the use of the catalyst support according to the invention and the use of the catalyst support obtainable with the process according to the invention in the manufacture of a catalyst for the synthesis of vinyl acetate monomers.

  According to a preferred embodiment of the use according to the invention, it is provided that the catalyst is a shell catalyst in a shell comprising Pd and Au with an oxidation state of 0.

  The following examples serve to illustrate the invention.

Example 1
Production of catalyst carrier according to the present invention 700 g of a spherical KA carrier having a parameter shown in Table 1 having a diameter of about 5 mm, which is commercially available from Zoot Chemie AG, was placed in a round bottom flask, and 25 ° C hydrochloric acid was used at 50 ° C. A total of 30 hours of treatment was performed at a temperature exceeding that.
The treated carrier obtained was washed with water and then dried.
The dried support was calcined in the temperature range between 450 ° C. and 670 ° C. for 5 hours to obtain a catalyst support according to the present invention having the parameters shown in Table 1.

※ 表１中の前記かさ密度 (圧縮密度) は、内径６ｃｍの１リットルメスシリンダー内で再現精度約±１ｇ／ｌで測定された。

* The bulk density (compression density) in Table 1 was measured in a 1 liter graduated cylinder with an inner diameter of 6 cm with a reproducibility of about ± 1 g / l.

Example 2
2.867 g of Na ₂ PdCl ₄ solution (Pd content 19.64%) was added into a homogeneous solution mixed with 0.505 g of HAuCl ₄ solution (Au content 41.81%) and 40.41 g of H ₂ O. .
After adding 65 g of the catalyst support according to the invention of Example 1 of the invention, they were rotated for 65 minutes at room temperature in a round bottom flask until dry.
After impregnation, 81.93 g of a 0.38 M base mixture consisting of a mixture of 50:50 NaOH: KOH (ie 40.965 g, 0.38 mol NaOH + 40.965 g, 0.38 mol KOH) is the carrier sphere. The whole was left overnight at room temperature for 16.5 hours.
After draining the fixing solution (base solution), the catalyst precursor thus produced was reduced with 73.14 g of 10% NaH ₂ PO ₂ solution for 2 hours.
After draining the reducing solution, the carrier spheres were washed with demineralized water for 19 hours at room temperature, with periodic water changes to remove Cl.
The final conductivity value of the washing water was 4.6 μS. The catalyst was then dried in a fluid bed dryer at 90 ° C. for 1 hour.
The dried catalyst was usually impregnated with a mixture of 25.25 g of a 2 molar KOAc solution and 19.18 g of H ₂ O and left to stand at room temperature for 1 hour.
Finally, re-drying with a fluid bed dryer was performed at 90 ° C. for 1 hour.

The 38 catalyst spheres thus produced were fixed bed tube reactors at room temperature 145 ° C., 10 bar, 550 ml / min, 15 vol% HOAc in nitrogen, 6 vol% O ₂ , 39 vol% C _2. The reactor was exposed to a feed gas consisting of H ₄ , and the reactor output was measured using gas chromatography.

The selectivity (of ethylene relative to VAM) is calculated according to the following formula:

_{S (C 2 H 4) =} VAM moles / (VAM moles + CO _2/2 mol).

The resulting space-time yield is obtained in ng VAM / 1 catalyst / hour.
The oxygen conversion rate is (in O ₂ mol-out O ₂ mol) / in O ₂ mol,
Is calculated according to

The catalyst produced using the catalyst support according to the present invention has a space-time yield of 474 g VAM / 1 catalyst / hour at an S (C ₂ H ₄ ) selectivity of 93.5% and an oxygen conversion of 30% ( Measured using gas chromatography).

Example 3 (comparative example)
2.867 g of Na ₂ PdCl ₄ solution (Pd content 19.64%) was added into a homogeneous solution mixed with 0.505 g of HAuCl ₄ solution (Au content 41.81%) and 35.997 g of H ₂ O. .
After adding 65 g of commercially available KA carrier to Example 1 of the present invention, they were rotated for 65 minutes at room temperature in a round bottom flask until dry.
After impregnation, 81.93 g of a 0.38 M base mixture consisting of a mixture of 50:50 NaOH: KOH (ie 40.965 g, 0.38 mol NaOH + 40.965 g, 0.38 mol KOH) is the carrier sphere. The whole was left overnight at room temperature for 16.5 hours.
After draining the fixing solution (base solution), the catalyst precursor thus produced was reduced with 73.14 g of 10% NaH ₂ PO ₂ solution for 2 hours.
After draining the reducing solution, the carrier spheres were washed with demineralized water for 19 hours at room temperature, with periodic water changes to remove Cl.
The final conductivity value of the washing water was 4.6 μS. The catalyst was then dried in a fluid bed dryer at 90 ° C. for 1 hour.
The dried catalyst was usually impregnated with a mixture of 25.25 g of a 2 molar KOAc solution and 19.18 g of H ₂ O and left to stand at room temperature for 1 hour.
Finally, re-drying with a fluid bed dryer was performed at 90 ° C. for 1 hour.

The 38 catalyst spheres thus produced were fixed bed tube reactors at room temperature 145 ° C., 10 bar, 550 ml / min, 15 vol% HOAc in nitrogen, 6 vol% O ₂ , 39 vol% C _2. The reactor was exposed to a feed gas consisting of H ₄ , and the output of the reactor was measured using gas chromatography.

The catalyst produced using the catalyst support according to the present invention has a space-time yield of 440 g VAM / 1 catalyst / hour (gas) at 92.0% S (C ₂ H ₄ ) selectivity and 31% oxygen conversion. (Measured using chromatography).

Claims (47)

An open-pored catalyst support comprising a material comprising natural layered silicate,
The acidity is from 10 μval to 60 μval,
The average pore size is 10.5 nm to 14 nm,
The specific surface area is 160 m ² / g to 175 m ² / g,
The bulk density is from 480 g / l to 550 g / l,
A catalyst support having an Al ₂ O ₃ content of less than 2.5% by weight and a water absorption of greater than 65%.   The catalyst carrier according to claim 1, wherein the average pore diameter is 10.5 nm to 12 nm.   The catalyst carrier according to claim 1 or 2, wherein the natural layered silicate is montmorillonite.   The catalyst carrier according to claim 3, wherein the montmorillonite is present as a constituent of bentonite.   The catalyst carrier according to any one of the preceding claims, wherein the natural layered silicate is an acid activated natural layered silicate. The catalyst support according to any one of the preceding claims, wherein the specific surface area is 165 m ² / g to 170 m ² / g.   The catalyst carrier according to any one of the preceding claims, wherein the hardness exceeds 60N.   The catalyst support according to any one of the preceding claims, wherein the acidity is from 20 µval / g to 60 µval / g.   Catalyst support according to any one of the preceding claims, characterized in that the proportion of the natural layered silicate in the catalyst support is at least 50% by weight.   Catalyst support according to any one of the preceding claims, characterized in that the total pore volume is from 0.25 ml / g to 0.8 ml / g.   Catalyst support according to any one of the preceding claims, characterized in that at least 80% of the total pore volume of the catalyst support is formed from mesoporous and macroporous.   Catalyst support according to any one of the preceding claims, characterized in that the bulk density is from 480 g / l to 520 g / l. Catalyst support according to any one of the preceding claims, characterized in that the natural layered silicate contained in the catalyst support has an SiO ₂ content of at least 65% by weight.   The catalyst carrier according to any one of the preceding claims, wherein the catalyst carrier is formed as a molded body.   The catalyst carrier according to any one of the preceding claims, wherein the maximum size is 1 mm to 25 mm.   The catalyst carrier according to claim 14 or 15, wherein the catalyst carrier is a sphere.   The catalyst carrier according to claim 16, wherein the diameter of the sphere is 2 mm to 10 mm.   Any of the preceding claims, doped with at least one oxide of a metal selected from the group consisting of Hf, Ti, Nb, Ta, W, Mg, Re, Y and Fe. The catalyst support according to Item.   The catalyst carrier according to claim 18, wherein the proportion of the dopant oxide in the catalyst carrier is 1 wt% to 25 wt%. The catalyst carrier according to any one of the preceding claims, which is free of ZrO ₂ . The average pore size is less than 10.5 nm,
The specific surface area exceeds 175 m ² / g,
The bulk density exceeds 550 g / l,
Al ₂ O ₃ content exceeds 2.5% by weight, and water absorption exceeds 65%,
Supplying a first open pore catalyst support composed of a material containing natural layered silicate;
Treating the first catalyst support with a mineral acid to obtain a second catalyst support;
A method involving that. The first catalyst support,
The acidity is from 10 μval to 60 μval,
The average pore size is 10.5 nm to 14 nm,
The specific surface area is 160 m ² / g to 175 m ² / g,
The bulk density is from 480 g / l to 550 g / l,
The treatment according to claim 21, characterized in that the treatment with mineral acid is carried out until a second catalyst support is obtained with an Al ₂ O ₃ content of less than 2.5% by weight and a water absorption of greater than 65%. Method.   23. A process according to claim 21 or 22, wherein the treatment with mineral acid is carried out over a period of 5 to 100 hours.   24. A method according to any one of claims 21 to 23, wherein the treatment with mineral acid is carried out at a temperature above 50 <0> C.   25. A method according to any one of claims 21 to 24, wherein the second catalyst support is washed after the treatment with the mineral acid.   26. The method of claim 25, wherein the second catalyst support is calcined after washing.   27. A method according to any one of claims 21 to 26, wherein the natural layered silicate is montmorillonite.   28. The method of claim 27, wherein the montmorillonite is present as a constituent of bentonite.   29. A method according to any one of claims 21 to 28, wherein the natural layered silicate is an acid activated natural layered silicate. 30. The method according to any one of claims 21 to 29, wherein the second catalyst support has a specific surface area of 165 m < ² > / g to 170 m < ² > / g.   The method according to any one of claims 21 to 30, wherein the hardness of the second catalyst carrier exceeds 60N.   32. The method according to any one of claims 21 to 31, wherein the acidity of the first catalyst support is from 1 [mu] val / g to 80 [mu] val / g.   33. A process according to any one of claims 21 to 32, wherein the proportion of natural layered silicate in the first catalyst support is at least 50% by weight.   34. A method according to any one of claims 21 to 33, wherein the total pore volume of the first catalyst support is from 0.25 ml / g to 0.8 ml / g.   35. A method according to any one of claims 21 to 34, wherein at least 80% of the total pore volume of the catalyst support is formed from mesoporous and macroporous.   36. A process according to any one of claims 21 to 35, wherein the bulk density of the second catalyst support is from 480 to 520 g / l. The SiO ₂ content of the first of the natural layered silicate contained in the catalyst carrier, the method according to any one of claims 21 to 36, characterized in that at least 65% by weight.   The method according to any one of claims 21 to 37, wherein the first catalyst carrier is formed as a molded body.   The method according to any one of claims 21 to 38, wherein the maximum size of the first catalyst support is 1 mm to 25 mm.   40. A method according to claim 38 or 39, wherein the first catalyst support is a sphere.   41. The method of claim 40, wherein the sphere has a diameter of 2 mm to 10 mm.   The first catalyst support is doped with at least one oxide of a metal selected from the group consisting of Hf, Ti, Nb, Ta, W, Mg, Re, Y, and Fe. 42. A method according to any one of claims 21 to 41.   43. The method of claim 42, wherein the proportion of dopant oxide in the first catalyst support is 1 wt% to 25 wt%. The method according to any one of claims 21 to 43 wherein the first catalyst carrier characterized in that it is a ZrO ₂ free.   The catalyst carrier according to any one of claims 1 to 20, which is obtained by the method according to any one of claims 21 to 44.   46. Use of a catalyst support according to claims 1 to 20 or 45 in the manufacture of a catalyst for the synthesis of vinyl acetate monomer.   47. Use according to claim 46, wherein the catalyst is a shell catalyst in a shell containing Pd and Au with an oxidation state of 0.