阅读说明：本技术 负载于碳涂覆二氧化硅-氧化铝载体上的贵金属-过渡金属复合催化剂及其制备方法 (Noble metal-transition metal composite catalyst loaded on carbon-coated silica-alumina carrier and preparation method thereof ) 是由 金正权 明岏在 陆宣佑 全烽植 于 2018-12-26 设计创作，主要内容包括：本发明涉及负载于碳涂覆二氧化硅-氧化铝载体上的贵金属-过渡金属复合催化剂及使用该贵金属-过渡金属复合催化剂的环己烷二甲醇的制备方法,当使用碳涂覆负载催化剂在水溶液中通过环己烷二羧酸(Cyclohexane dicarboxylic acid,CHDA)的氢化反应来生产环己烷二甲醇(Cyclohexane dimethanol,CHDM)时,能够获得比现有的催化剂更快的反应速率及催化稳定性。(The present invention relates to a noble metal-transition metal composite catalyst supported on a carbon-coated silica-alumina carrier and a method for preparing cyclohexanedimethanol using the same, wherein when the Cyclohexanedimethanol (CHDM) is produced by hydrogenation of cyclohexanedicarboxylic acid (CHDA) in an aqueous solution using the carbon-coated supported catalyst, a faster reaction rate and catalytic stability can be obtained as compared to the existing catalyst.)

1. A noble metal-transition metal composite catalyst loaded on a carbon-coated carrier, wherein a noble metal-transition metal is loaded on a carbon-coated silica-alumina carrier,

40 to 95 parts by weight of the alumina (Al) per 100 parts by weight of the total amount of the carrier₂O₃) And 5 to 60 parts by weight of Silica (SiO)₂)，

And comprising 1 to 20 parts by weight of the noble metal and the transition metal with respect to 100 parts by weight of the carbon-coated silica-alumina carrier.

2. The noble metal-transition metal composite catalyst supported on a carbon-coated carrier according to claim 1, characterized in that,

the noble metal includes at least one selected from palladium (Pd), rhodium (Rh), ruthenium (Ru), and platinum (Pt).

3. The noble metal-transition metal composite catalyst supported on a carbon-coated carrier according to claim 1, characterized in that,

the noble metal is contained in an amount of 1 to 10 parts by weight based on 100 parts by weight of the carrier.

4. The noble metal-transition metal composite catalyst supported on a carbon-coated carrier according to claim 1, characterized in that,

the transition metal includes at least one selected from tin (Sn), iron (Fe), rhenium (Re), and gallium (Ga).

5. The noble metal-transition metal composite catalyst supported on a carbon-coated carrier according to claim 1, characterized in that,

the transition metal is contained in an amount of 1 to 10 parts by weight based on 100 parts by weight of the carrier.

6. The noble metal-transition metal composite catalyst supported on a carbon-coated carrier according to claim 1, characterized in that,

the precursor of the noble metal and the precursor of the transition metal are supported on the support in the same molar ratio.

7. The noble metal-transition metal composite catalyst supported on a carbon-coated carrier according to claim 1, characterized in that,

the carbon is coated on the silica-alumina surface by a carbonization process.

8. A hydrogenation process, characterized in that,

hydrogenation of dicarboxylic acid functional groups (dicarboxylic acid groups) using a catalyst according to any of claims 1 to 7.

9. The hydrogenation process according to claim 8,

the dicarboxylic acid is one selected from the group consisting of oxalic acid (oxalic acid), malonic acid (maleic acid), succinic acid (succinic acid), glutaric acid (glutaric acid), adipic acid (adipic acid), pimelic acid (pimelic acid), suberic acid (suberic acid), azelaic acid (azelaic acid), sebacic acid (sebasic acid), malic acid (malic acid), aspartic acid (aspartic acid), glutamic acid (glutamic acid), phthalic acid (phthalic acid), isophthalic acid (isophtalic acid), terephthalic acid (terephthalic acid), and cyclohexanedicarboxylic acid (cyclohexanedicarboxylic acid).

10. Cyclohexanedimethanol (CHDM), characterized in that,

prepared by hydrogenation of Cyclohexanedicarboxylic acid (CHDA) using a catalyst as claimed in any one of claims 1 to 7.

11. A method for preparing a noble metal-transition metal composite catalyst supported on a carbon-coated carrier, characterized by comprising the steps of:

(a) boric acid (boric acid) was dissolved in an aqueous carbon precursor solution and then supported on silica-alumina (SiO)₂-Al₂O₃) To prepare a composite;

(b) carbonizing the composite;

(c) on the silica-alumina (SiO) coated with said carbon₂-Al₂O₃) A noble metal-transition metal carrier; and

(d) the silica-alumina (SiO) supported on the carbon-coated silica-alumina was treated with hydrogen gas₂-Al₂O₃) The noble metal-transition metal oxide on the support is reduced.

12. The method for producing a noble metal-transition metal composite catalyst supported on a carbon-coated carrier according to claim 11,

in the step (a), the carbon precursor and the boric acid are charged in a weight ratio of 1: 0.005 to 0.1.

13. The method for producing a noble metal-transition metal composite catalyst supported on a carbon-coated carrier according to claim 11,

in the step (a), the complex is prepared by loading the complex on the carrier by an incipient wetness impregnation method (impregnation).

14. The method for producing a noble metal-transition metal composite catalyst supported on a carbon-coated carrier according to claim 11,

in the step (b), the carbonization process is performed in a nitrogen atmosphere at a temperature ranging from 300 to 700 ℃.

15. The method for producing a noble metal-transition metal composite catalyst supported on a carbon-coated carrier according to claim 11,

in the step (c), 1 to 20 parts by weight of the noble metal and the transition metal are supported with respect to 100 parts by weight of the carrier.

16. The method for producing a noble metal-transition metal composite catalyst supported on a carbon-coated carrier according to claim 11,

in the step (d), the reduction process is carried out at a temperature of 400-600 ℃.

Technical Field

The present invention relates to a noble metal-transition metal composite catalyst supported on a carbon-coated silica-alumina carrier and a method for preparing the same, and more particularly, to a noble metal-transition metal composite catalyst supported on a carbon-coated silica-alumina carrier and a method for preparing the same, which can obtain a faster reaction rate and catalytic stability than the existing catalyst when Cyclohexanedimethanol (CHDM) is produced by hydrogenation of cyclohexanedicarboxylic acid (CHDA) in an aqueous solution using a carbon-coated supported catalyst.

Background

Cyclohexanedimethanol (CHDM, 1, 4-cyclohexenedimethanol) is a basic raw material for producing polyester or polyamide resins, and is currently commercially produced in asia by SK chemistry, Mitsubishi (Mitsubishi) business, and SK NJC, a consortium of new japanese physics and chemistry (shin nippon Rika), and occupies the entire market worldwide by Indorama (formerly) Eastman (Eastman)) companies. The CHDM market is on a growing trend and is expected to grow in the future for high value added polyester resins, and thus needs to be stable in supply and demand. It is said that, at present, CHDM production is maintained at 100KTA scale by Indorama and at 20KTA scale by SK NJC, and SK NJC is planned to increase production to 60KTA by 18 years, and recently, one production line has been added on the basis of the existing two production lines.

It is known from the literature that processes for preparing CHDM using Purified Terephthalic Acid (PTA) are roughly divided into three types. The first method is a method in which PTA of Sumitomo seikavailable chemical (Sumitomo seikavailable) is ionized in an aqueous solution using NaOH to produce Salt (Salt) to increase the solubility of PTA and to perform hydrogenation. The synthesis method has the advantage that the hydrogenation reaction temperature can be reduced (40-130 ℃) along with the increase of PTA solubility at low temperature, but HCl is required to be used for neutralization treatment after the reaction is finished, so Na is recovered⁺The number of ionic steps is not necessarily small, and Na remaining after completion of the reaction⁺Salt (Salt) affects the polymerization of PETG, and a Brine solution (Brine) containing NaCl causes an excessive cost of wastewater treatment, thus adversely affecting the production process. The second method, which is a preparation method adopted by Indorama and SK NJC, is a process of preparing CHDM via Dimethyl cyclohexanedicarboxylate (DMCD) after preparing Dimethyl terephthalate (DMT) from PTA through esterification (esterification). This process uses a copper (Cu) -based catalyst or a chromium (Cr) -based catalyst when producing CHDM using DMCD, and therefore, the catalyst is relatively inexpensive in terms of price, but the whole is a three-step (PTA DMT → DMCD CHDM) production process, and therefore, is disadvantageous in terms of process. In addition, in the above process, the two processes use solvents different from each other, and therefore, there is a problem that a large amount of wastewater is generated, and DMT, which is more expensive than the raw material PTA, is actually used as a raw material.

In contrast, as a third method, a process for producing CHDM from PTA via CHDA, in which the active metal uses a noble metal ruthenium when performing a CHDA hydrogenation reaction, is disadvantageous in terms of the price of the catalyst, but the final product CHDM can be obtained by a two-step process (PTA CHDA → CHDM), and therefore can be regarded as being advantageous in terms of economy, as long as the product cost can be reduced by shortening the process and the competitiveness of the process technology can be ensured.

In the two-step process for producing CHDA and CHDM from PTA, the second-step reaction, which is a reaction for converting into alcohol (alcohol) by hydrodeoxygenation of dicarboxylic acid (di-carboxylic acid), is more difficult than the first-step reaction for saturating aromatic rings (saturation) of TPA, and thus constitutes a bottleneck (huddle) in the commercialization stage. Therefore, there is an urgent need to develop a catalyst having high efficiency and long service life suitable for the hydrogenation process of CHDA as the second step reaction.

Disclosure of Invention

Technical problem

The present invention is directed to solving the above-mentioned problems of the prior art and the technical problems that have been conventionally proposed.

The present invention is directed to a noble metal-transition metal composite catalyst supported on a carbon-coated silica-alumina carrier, which can be used in the case of using silica-alumina (SiO) supported on carbon, and a method for preparing the same₂-Al₂O₃) The noble metal-transition metal composite catalyst maintains high activity and catalytic reaction stability when diol (diol) is produced from dicarboxylic acid (dicarboxylic acid).

Technical scheme

The noble metal-transition metal composite catalyst supported on a carbon-coated carrier of the present invention for achieving these objects supports a noble metal-transition metal on a carbon-coated silica-alumina carrier,

the alumina (Al) may be included in an amount of 40 to 95 parts by weight with respect to 100 parts by weight of the total amount of the carrier₂O₃) And 5 to 60 parts by weight of Silica (SiO)₂)，

And may include 1 to 20 parts by weight of the noble metal and the transition metal with respect to 100 parts by weight of the carbon.

In a preferred embodiment of the present invention, the noble metal may include at least one selected from the group consisting of palladium (Pd), rhodium (Rh), ruthenium (Ru), and platinum (Pt).

In a preferred embodiment of the present invention, the noble metal may be contained in an amount of 1 to 10 parts by weight based on 100 parts by weight of the carrier.

In a preferred embodiment of the present invention, the transition metal may include at least one selected from tin (Sn), iron (Fe), rhenium (Re), and gallium (Ga).

In a preferred embodiment of the present invention, the transition metal may be included in an amount of 1 to 10 parts by weight based on 100 parts by weight of the carrier.

In a preferred embodiment of the present invention, the precursor of the noble metal and the precursor of the transition metal may be supported on the support in the same molar ratio.

In a preferred embodiment of the present invention, the carbon may be coated on the surface of the silica-alumina through a carbonization process.

In another aspect, the present invention provides a hydrogenation method for hydrogenating dicarboxylic acid functional groups (dicarboxylic acid groups) using the catalyst and cyclohexanedimethanol prepared by hydrogenation of cyclohexanedicarboxylic acid using the catalyst.

In a preferred embodiment of the present invention, the dicarboxylic acid may include one selected from the group consisting of oxalic acid (oxalic acid), malonic acid (maleic acid), succinic acid (succinic acid), glutaric acid (glutaric acid), adipic acid (adipic acid), pimelic acid (pimelic acid), suberic acid (suberic acid), azelaic acid (azelaic acid), sebacic acid (sebasic acid), malic acid (malic acid), aspartic acid (aspartic acid), glutamic acid (glutaminic acid), phthalic acid (phthalic acid), isophthalic acid (isophalic acid), terephthalic acid (terephthalic acid), and cyclohexanedicarboxylic acid (cyclohexanedicarboxylic acid).

In addition, the present invention provides a method for preparing a noble metal-transition metal composite catalyst supported on a carbon-coated silica-alumina carrier, which may include the steps of:

(a) boric acid (boric acid) was dissolved in an aqueous carbon precursor solution and then supported on silica-alumina (SiO)₂-Al₂O₃) To prepare a composite;

(b) carbonizing the composite;

(c) on the silica-alumina (SiO) coated with said carbon₂-Al₂O₃) A noble metal-transition metal carrier; and

(d) coating the carbon support with silica-alumina (SiO) using hydrogen₂-Al₂O₃) The noble metal-transition metal oxide on the support is reduced.

In a preferred embodiment of the present invention, in the step (a), the carbon precursor and the boric acid may be charged in a weight ratio of 1: 0.005 to 0.1.

In a preferred embodiment of the present invention, in the step (a), the complex may be prepared by loading the carrier with an incipient-wetness impregnation method.

In a preferred embodiment of the present invention, the carbonization process may be performed in a nitrogen atmosphere at a temperature ranging from 300 to 700 ℃.

In a preferred embodiment of the present invention, in the step (c), 1 to 20 parts by weight of the noble metal and the transition metal may be supported with respect to 100 parts by weight of the carrier.

In a preferred embodiment of the present invention, in the step (d), the reduction process may be performed at a temperature ranging from 400 to 600 ℃.

Advantageous effects

As described above, the noble metal-transition metal catalyst supported on a carbon-coated silica-alumina carrier and the method for preparing the same according to the present invention can be applied to the use of a carbon-coated silica-alumina (SiO)₂-Al₂O₃) The noble metal-transition metal catalyst can maintain high activity and catalytic reaction stability when glycol (diol) is produced from dicarboxylic acid (dicarboxylic acid).

Drawings

Fig. 1 is a schematic view showing a production process of a process for supporting a noble metal-transition metal on a carbon-coated silica-alumina carrier according to an embodiment of the present invention.

Fig. 2 is a graph showing the results of CHDM production reactions using a catalyst having a noble metal-transition metal supported on a carbon-coated silica-alumina carrier according to an embodiment of the present invention.

Fig. 3 is a graph showing the results of CHDM production reactions using a catalyst having a noble metal-transition metal supported on an uncoated silica-alumina carrier according to one embodiment of the present invention.

Fig. 4 is a graph showing CHDM production reaction efficiency results using catalysts having noble metal-transition metal supported on carbon-coated silica-alumina supports and non-carbon-coated silica-alumina supports, respectively, according to an embodiment of the present invention.

Detailed Description

The following description of the invention will refer to specific embodiments, which are shown by way of example, and in which the invention may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice the invention. The various embodiments of the invention are distinct from each other, but are not necessarily mutually exclusive. For example, the specific shape, structure, and characteristics described herein are related to one embodiment, and may be implemented in other embodiments without departing from the technical spirit and scope of the present invention.

The following detailed description is, therefore, not to be taken in a limiting sense, and the scope of the present invention is defined only by the appended claims and equivalents thereof, as appropriate.

In addition, in the present specification, unless otherwise specified, "substituted" or "substituted" means that one or more hydrogen atoms in the functional group of the present invention are substituted with at least one substituent selected from the group consisting of a halogen atom (-F, -Cl, -Br, or-I), a hydroxyl group, a nitro group, a cyano group, an amino group, an amidino group, a hydrazine group, a hydrazone group, a carboxyl group, an ester group, a ketone group, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alicyclic organic group, a substituted or unsubstituted aryl group, a substituted or unsubstituted alkenyl group, a substituted or unsubstituted alkynyl group, a substituted or unsubstituted heteroaryl group, and a substituted or unsubstituted heterocyclic group, and a plurality of the substituents may also be linked to each other to form a ring.

In the present invention, unless otherwise specified, "substituted" means that a hydrogen atom is substituted with a substituent such as a halogen atom, a hydrocarbon group having 1 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, an aryloxy group having 6 to 20 carbon atoms, or the like.

In addition, unless otherwise specified, the "hydrocarbon group" means a saturated or unsaturated hydrocarbon group of a linear, branched or cyclic type, and the alkyl group, alkenyl group, alkynyl group and the like may be of a linear, branched or cyclic type.

In addition, in the present specification, unless otherwise specified, "alkyl" means an alkyl group of C1 to C30, and "aryl" means an aryl group of C6 to C30. In the present description, "heterocyclic group" means a group containing 1 to 3 heteroatoms selected from O, S, N, P, Si and combinations thereof in one ring, and for example, represents pyridine, thiophene, pyrazine and the like, but is not limited thereto.

In the detailed description of the present invention, the term dicarboxylic acid (dicarboxylic acid) denotes an organic acid comprising two carboxylic acid functions within one molecule. For example, the dicarboxylic acid has a formula represented by HOOC-R-COOH, and in the present invention, R may preferably be an alkyl group or an aryl group.

Hereinafter, preferred embodiments of the present invention will be described in detail so that those skilled in the art can easily carry out the present invention.

As described above, the conventional technology for hydrogenation of cyclohexanedicarboxylic acid has a limitation in producing cyclohexanedimethanol by using an inexpensive carrier and a catalyst ensuring higher reactivity and hydrothermal stability than conventional catalysts.

In view of the above, the present invention provides a noble metal-transition metal catalyst supported on a carbon-coated carrier, wherein a noble metal-transition metal is supported on a carbon-coated silica-alumina carrier, and the noble metal-transition metal catalyst comprises 40 to 95 parts by weight of alumina (Al) per 100 parts by weight of the carrier in total₂O₃) And 5 to 60 parts by weight of Silica (SiO)₂) And relative to 100 parts by weight of the carbon, containing 1 to 20 parts by weight of the noble metal and the transition metal, and thus a solution to the above-mentioned problems has been sought.

The carrier functions as a catalyst poison by being affected by an acid, and therefore, a metal oxide such as silica, alumina, zirconia, titania, or the like, a composite oxide such as silica-alumina, or the like, acidic activated carbon, zeolite, or the like can be used.

Among them, in general, alumina carriers have a disadvantage that the structure of γ -alumina changes to a boehmite structure under hydrothermal reaction conditions, and therefore, as a method for improving hydrothermal stability of alumina, various methods of pretreatment using a second other component have been introduced. In addition, when silica is used as a carrier, a phenomenon of reduction of metallic cobalt in a reduction process and a reduction in activity due to the reduction can be observed due to strong bonding of cobalt to the carrier as compared with an alumina carrier, and as a method for overcoming the problem, a conventional technique such as a method of pretreating the surface of silica with a metal such as zirconium is introduced.

Therefore, Al is present in the carrier of the present invention at the same time₂O₃And SiO₂Two components, thereby improving disadvantages when the alumina and silica components are separately used, respectively, and is used as a catalyst for a dicarboxylic acid (dicarboxylic acid) hydrogenation reaction through a carbonization process after a solution including a carbon precursor is supported on the alumina-silica support by an incipient-wetness impregnation method (incipient-wetness impregnation) to form a complex.

Hereinafter, the composition of the noble metal-transition metal catalyst supported on the carbon-coated carrier will be described in more detail.

First, according to the present invention, preferably, the alumina component may be contained in an amount of 40 to 95 parts by weight, preferably 55 to 85 parts by weight, and more preferably 80 to 85 parts by weight, relative to 100 parts by weight of the total amount of the carrier. In this case, when the content of the alumina component is less than 40 parts by weight, there is a problem in that a large amount of by-products are generated by hydrocracking (hydrocracking) during the reaction due to the highly acidic sites of the silica-alumina carrier, and when the content of the alumina component is more than 95 parts by weight, there is a problem in hydrothermal stability of the alumina, and thus the above range is preferable.

In addition, it is preferable that the silica component may be contained in an amount of 5 to 60 parts by weight, preferably 5 to 35 parts by weight, and more preferably 5 to 10 parts by weight, relative to 100 parts by weight of the total amount of the carrier. At this time, when the content of the silica component is less than 5 parts by weight, there is a problem in hydrothermal stability of alumina, and when the content of the silica component is more than 50 parts by weight, there is a problem in that hydrocracking (hydrocracking) is a problem due to highly acidic sites of the silica-alumina carrier, and thus, the above range is preferable.

Next, the noble metal may include at least one selected from palladium (Pd), rhodium (Rh), ruthenium (Ru), and platinum (Pt). Wherein, according to the present invention, the content of the noble metal may be 1 to 20 parts by weight, preferably 1 to 10 parts by weight, and more preferably 3 to 8 parts by weight, with respect to 100 parts by weight of the silica-alumina support coated with the carbon. In this case, when the content of the noble metal is less than 1 part by weight, there is a problem in that the conversion efficiency is low and the production efficiency is lowered, and when the content of the noble metal is more than 10 parts by weight, there is a problem in that an additional cost is generated in terms of a process due to a high catalyst price and low selectivity of the target product, and thus, the above range is preferable.

Next, the transition metal may include at least one selected from tin (Sn), iron (Fe), rhenium (Re), and gallium (Ga). Wherein, according to the present invention, the content of the transition metal may be 1 to 20 parts by weight, preferably 1 to 10 parts by weight, and more preferably 3 to 8 parts by weight, with respect to 100 parts by weight of the silica-alumina support coated with the carbon. In this case, when the content of the transition metal is less than 1 part by weight, there is a problem in that separation cost and recovery cost in a process are excessively high due to reduction of conversion efficiency of a reaction or reduction of selectivity of a target product, and when the content of the transition metal is more than 10 parts by weight, an additional process is required due to generation of a large amount of by-products, and thus the above range is preferable.

In another aspect, the present invention provides a hydrogenation method using the catalyst, and in a specific example, cyclohexanedimethanol can be produced by performing a hydrogenation reaction of cyclohexanedicarboxylic acid on the catalyst.

Hereinafter, a method for preparing a noble metal-transition metal composite catalyst supported on a carbon-coated carrier, which comprises the above composition, will be described.

The invention provides a preparation method of the noble metal-transition metal composite catalyst loaded on the carbon coating carrier, which specifically comprises the following steps: boric acid (boric acid) was dissolved in an aqueous carbon precursor solution and then supported on silica-alumina (SiO)₂-Al₂O₃) To prepare a composite; carbonizing the composite; on the silica-alumina (SiO) coated with said carbon₂-Al₂O₃) A noble metal-transition metal carrier; and using hydrogen gas to support on the silica-alumina (SiO)₂-Al₂O₃) The noble metal-transition metal oxide on the support is reduced.

Referring to fig. 1, boric acid (boric acid) is dissolved in an aqueous carbon precursor solution and then supported on silica-alumina (SiO)₂-Al₂O₃) After preparing the composite, the composite is introduced under a nitrogen atmosphere at a temperature of 500 c and subjected to a carbonization process. Thereafter, the noble metal precursor and the transition metal precursor, which comprise the above content ratios, are simultaneously supported to carbon-coated silica-alumina (SiO) by a co-impregnation method (co-impregnation), respectively₂-Al₂O₃) And reducing the noble metal-transition metal oxide with hydrogen to prepare a catalyst comprising the noble metal-transition metal on a carbon-coated support.

In the present invention, the carbon precursor and the boric acid to be added to the carbon precursor aqueous solution may be added in a weight ratio of 1: 0.005 to 0.1, preferably in a weight ratio of 1: 0.007 to 0.07, and more preferably in a weight ratio of 1: 0.01 to 0.05. At this time, when the content of the boric acid is less than 0.005 by weight, there is a problem in that the charge density (electronic charge density) of the active metal is decreased and the hydrogen adsorption amount is decreased, and finally the catalyst reaction activity is decreased, and when the weight ratio of the boric acid is more than 0.1 by weight, an excessive amount of boric acid is dissolved into the objective product and the quality of the product is problematic, and thus, the above range is preferable.

In the following, preferred embodiments (examples) are presented to aid in understanding the present invention. However, the following examples are only for the purpose of facilitating understanding of the present invention, and the present invention is not limited to the following test examples.