Patent Description:
Oil refinery and petrochemical plants produce large amounts of hydrocarbons, which contain large amounts of unsaturated hydrocarbons which cause problems during subsequent process steps or storage periods. Examples of these unsaturated hydrocarbons comprise acetylene, propyne, propadiene, butadiene, vinylacetylene, butyne, phenylacetylene, styrene and the like.

As an example, acetylene is known to reduce the activity of a catalyst in an ethylene polymerization process and cause a deterioration in the quality of a polymer. Therefore, in a process of synthesizing polyethylene from ethylene, the concentration of acetylene contained in ethylene raw materials needs to be reduced to the minimal level.

These undesired unsaturated compounds are usually removed to several PPM or less by a selective hydrogenation reaction. It is very important to enhance the selectivity from a reaction of selectively hydrogenating unsaturated compounds to the desired compound and avoid coke formation, which reduces the reaction activity.

In the related art, nickel sulfate, tungsten/nickel sulfate or copper containing catalysts have been used for selective hydrogenation reactions. However, these catalysts have low catalytic activity even at high temperatures, and thus reduce polymer formation. Further, supported palladium (Pd) or Pd and silver (Ag) containing catalysts based on alumina or silica are also used in the selective hydrogenation process, but the selectivity is unsatisfactory or the activity is low.

Therefore, there is a need in the art for developing a catalyst for a hydrogenation reaction, which has excellent selectivity for a product of hydrogenation reaction and excellent catalytic activity.

<NPL> disclose a catalyst for a selective hydrogenation reaction comprising Pd supported on a covalent organic polymer containing diphenyl sulfide linkages.

<NPL> disclose a catalyst for a copper free acyl Sonogashira reaction comprising palladium nanoparticles (PdNps) embedded into a poly(<NUM>,<NUM>-phenylene sulfide) (PPS) polymer matrix.

The present application identifies a catalyst for a hydrogenation reaction of alkyne to alkene.

The present application is concerning the use of a catalyst in a hydrogenation reaction of alkyne to alkene, the catalyst comprising:.

The catalyst can be manufactured by a method comprising:.

A polymer support consisting of the repeating unit represented by Formula <NUM> can be applied as a support of a catalyst for a hydrogenation reaction.

The catalyst comprising the polymer support is characterized by having excellent stability in the reaction temperature range of the hydrogenation reaction and being able to improve the selectivity for the product of the hydrogenation reaction.

In addition, the catalyst has reaction characteristics which are differentiated from those of an alumina- or silica-based metal-supported catalyst in the related art, in which the reaction occurs on the surface of the metal due to a strong bond between a polymer support consisting of the repeating unit represented by Formula <NUM> and a hydrogen active metal cluster. The catalyst is characterized by having excellent stability within a reaction temperature range of the hydrogenation reaction and being able to improve the selectivity of alkene in the hydrogenation reaction of alkyne by suppressing the hydrogenation reactivity of alkene while maintaining the hydrogenation reactivity of alkyne.

Hereinafter, the present application will be described in more detail.

When one member is disposed "on" another member in the present specification, this comprises not only a case where the one member is brought into contact with another member, but also a case where still another member is present between the two members.

When one part "comprises" one constituent element in the present specification, unless otherwise specifically described, this does not mean that another constituent element is excluded, but means that another constituent element can be further comprised.

As described above, it is common to use a catalyst in which Pd is supported on an alumina or silica support as a catalyst for a hydrogenation reaction in the related art. However, the catalyst as described above has a problem in that the catalyst replacement cycle is short due to the rapid deactivation of the catalyst, and thus has a problem in that the process cost can be increased. Further, in order to improve the selectivity of the product of hydrogenation reaction in the related art, a modifier was introduced, but the introduction of the modifier has a problem in that the process cost can be increased and an additional separation process is required.

Thus, the present application was intended to identify a catalyst for a hydrogenation reaction, which has excellent selectivity for the product of hydrogenation reaction and excellent catalytic activity. In particular, the present inventors have studied a catalyst comprising a polymer support as a support which is applied to a catalyst for a hydrogenation reaction, thereby completing the present application.

The catalyst for a hydrogenation reaction comprises: a polymer support; and a catalytic component supported on the polymer support, in which the polymer support is consisting of a repeating unit represented by the following Formula <NUM>. <CHM>
in Formula <NUM>,.

The alkyl group of Formula <NUM> can be straight-chained or branched, and the number of carbon atoms thereof is not particularly limited, but is preferably <NUM> to <NUM>. Specific examples of the alkyl group comprise a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an n-butyl group, an isobutyl group, a tert-butyl group, a sec-butyl group, a <NUM>-methylbutyl group, a <NUM>-ethylbutyl group, and the like, but are not limited thereto.

Specific examples of the aryl groups of Formula <NUM> can comprise a phenyl group, a biphenyl group, a terphenyl group, a quaterphenyl group, a naphthyl group, an anthracenyl group, a phenanthrenyl group, a pyrenyl group, and the like, but are not limited thereto.

All of R1 to R4 of Formula <NUM> can be hydrogen.

The hydrocarbon ring can be an aromatic hydrocarbon ring, and specific examples thereof comprise a benzene ring, and the like, but are not limited thereto.

Formula <NUM> can be represented by any one of the following Formulae <NUM> to <NUM>. <CHM>
<CHM>
<CHM>
<CHM>
<CHM>
<CHM>
<CHM>
<CHM>
<CHM>
<CHM>.

A polymer support consisting of the repeating unit represented by Formula <NUM> can have a weight average molecular weight of <NUM>,<NUM>/mol to <NUM>,<NUM>/mol.

It is possible to exhibit high selectivity compared to a hydrogenation catalyst using an alumina or silica support in the related art in a selective hydrogenation reaction such as hydrogenation of alkyne to alkene by supporting a hydrogen active metal (a metal capable of forming hydrogen activated by contact with hydrogen molecules) in the polymer support. As an example, in the hydrogenation reaction of alkyne to alkene, in the case of an alumina- or silica-based metal supported catalyst in the related art, both alkyne and alkene are easily adsorbed on the surface of the metal, so that hydrogenation of alkyne to alkene and hydrogenation of alkene to alkane are non-selectively accomplished. However, when the polymer support is used, the surface of an active metal is surrounded by the polymer due to the strong binding power between the polymer support and the active metal. Therefore, based on the active metal, a reactant exhibiting a relatively stronger binding power than the binding power between the active metal and the polymer support, such as alkyne, is adsorbed on the active metal, but reactants exhibiting a relatively weaker binding power, such as alkene, have a reaction characteristic that the reactants cannot be adsorbed on the active metal. Due to these characteristics, a catalyst having an active metal supported on a polymer support can show high selectivity in a hydrogenation reaction of alkyne to alkene by suppressing the hydrogenation reactivity of alkene while maintaining the hydrogenation reactivity of alkyne as it is.

The catalytic component can comprise one or more of platinum (Pt), palladium (Pd), ruthenium (Ru), iron (Fe), nickel (Ni), cobalt (Co), molybdenum (Mo), gold (Au), silver (Ag), copper (Cu), titanium (Ti), gallium (Ga), cerium (Ce), aluminum (Al), zinc (Zn), and lanthanum (La).

A content of the catalytic component can be <NUM> wt% to <NUM> wt% and <NUM> wt% to <NUM> wt%, based on a total weight of the catalyst for a hydrogenation reaction. When the content of the catalytic component is less than <NUM> wt% based on the total weight of the catalyst for a hydrogenation reaction, the reactivity of the catalyst can deteriorate, so that the content is not preferred. Further, when the content of the catalyst component is more than <NUM> wt%, a relatively large amount of active metal is contained compared to the polymer support, so that the active metal can not be easily bonded to the polymer support, and accordingly, the selectivity of alkene is lowered by hydrogenation reaction, so that the actual benefit of the hydrogenation reaction caused by the increase in weight can be decreased.

A method for manufacturing the catalyst for a hydrogenation reaction comprises: preparing a polymer support consisting of the repeating unit represented by Formula <NUM>; and supporting a catalytic component on the polymer support.

The polymer support consisting of the repeating unit represented by Formula <NUM> can be synthesized by condensation polymerization of a dihalogenated aromatic compound and a sulfur supply source in an N-methyl-<NUM>-pyrrolidone (NMP) solvent. As the dihalogenated aromatic compound, various types can be selected, and an example thereof comprises p-dichlorobenzene, <NUM>,<NUM>-dichlorotoluene, <NUM>,<NUM>-dichloro-<NUM>,<NUM>,<NUM>,<NUM>-tetramethylbenzene, and the like. Further, the sulfur supply source is not particularly limited as long as the sulfur supply source is a solid sulfur supply source, and examples thereof comprise Na<NUM>S, K<NUM>S, and the like. A molar ratio of the dihalogenated aromatic compound to sulfur of the sulfur supply source can be <NUM> to <NUM>.

More specifically, the method for manufacturing a polymer support consisting of the repeating unit represented by Formula <NUM> can comprise: evaporating water by heating a mixture comprising a sulfur supply source and an organic solvent; obtaining a polymerization reaction product by introducing a dihalogenated aromatic compound and an organic solvent into the mixture and performing a condensation polymerization reaction on the resulting mixture; and washing the polymerization reaction product with water and then drying the washed polymerization reaction product. In the step of evaporating water by heating the mixture comprising the sulfur supply source and the organic solvent, water can be evaporated by heating and stirring the mixture at <NUM> to <NUM> for <NUM> hour to <NUM> hours. In the step of obtaining the polymerization reaction product by introducing a dihalogenated aromatic compound and an organic solvent into the mixture and performing a condensation polymerization reaction on the resulting mixture, the product can be polymerized by heating and stirring the mixture at <NUM> to <NUM> for <NUM> hours to <NUM> hours. In the step of washing the polymerization reaction product with water and then drying the washed polymerization reaction product, the polymerization reaction product can be washed with water at <NUM> to <NUM> and dried at <NUM> to <NUM> for <NUM> hours to <NUM> hours.

In the method for supporting a catalytic component on the polymer support, after an aqueous solution or organic solution (supporting solution) containing a compound as a precursor for the catalytic component is prepared, a catalyst can be synthesized by using an immersion method in which the polymer support is immersed in the supporting solution, dried, and then reduced with hydrogen gas and the catalytic component is supported, or by stirring the resulting polymer support with metal nanoparticles reduced in advance. As a precursor for the catalytic component, an organic metal compound such as Pd(acac)<NUM>, Pd(NO<NUM>)<NUM>·4NH<NUM>, Pt(acac)<NUM>, and Pt(NO<NUM>)<NUM>·4NH<NUM> can be used, but the precursor is not limited thereto.

When the catalytic component is supported on the polymer support by the immersion method, an aqueous solution or organic solution is prepared by dissolving a compound as a precursor for the catalytic component in water or an organic solvent in a volume corresponding to voids of the polymer support, the polymer support is immersed in the solution, the solvent is completely evaporated, the resulting product is dried, and then the polymer can be reduced while flowing hydrogen within a temperature at which the polymer is not impaired (< <NUM>). Further, after metal nanoparticles reduced in advance are dispersed in an organic solvent, the polymer support is put into the solution, the solution is stirred and subjected to ultrasonic treatment, and then a catalyst can be obtained by filtering the resulting solution until the color of the solution completely fades, and then drying the filtered product.

In the method for manufacturing the catalyst for a hydrogenation reaction, detailed contents of the polymer support consisting of the repeating unit represented by Formula <NUM>, the catalytic component, and the like are the same as those described above.

The catalyst can be applied to a hydrogenation reaction of alkene from alkyne. The catalyst can be applied not only to acetylene, but also to a hydrocarbon compound having a triple bond. Examples of the hydrocarbon compound comprise propyne, butyne, pentyne, hexayne, heptyne, octyne, and the like. Furthermore, in a compound comprising a functional group other than the triple bond or a double bond, for example, a compound having a benzene ring such as phenylacetylene, an alkyne compound having a carbonyl group, an alkyne compound having an alcohol group, an alkyne compound having an amine group, and the like, a hydrogenolysis reaction is suppressed, and only an alkyne group can be applied to a selective hydrogenation reaction to an alkene group.

Hereinafter, the present application will be described in detail with reference to Examples for specifically describing the present application. However, the Examples can be modified in various forms, and it is not intended that the scope of the present application is limited to the Examples described in detail below. The Examples are provided for more completely explaining the present application to the person with ordinary skill in the art.

After <NUM> of sodium sulfide hydrate (<NUM> wt% Na<NUM>S) and <NUM> of NMP were mixed, the resulting mixture was heated at <NUM> and dehydrated, and then <NUM> of p-dichlorobenzene was mixed with the dehydrated mixture, and polymerization was performed under stirring at <NUM> for <NUM> hours. Thereafter, a polymerization reaction product was filtered, washed with water at <NUM>, and then dried at <NUM> for <NUM> hours. The produced polymer is represented by "PH".

A polymer was synthesized in the same manner as in Synthesis Example <NUM>, except that <NUM> of <NUM>,<NUM>-dichlorotoluene was used instead of the p-dichlorobenzene.

A polymer was synthesized in the same manner as in Synthesis Example <NUM>, except that <NUM> of <NUM>,<NUM>-dibromonaphthalene was used instead of the p-dichlorobenzene.

A polymer was synthesized in the same manner as in Synthesis Example <NUM>, except that <NUM> of <NUM>,<NUM>-dichloro-p-xylene was used instead of the p-dichlorobenzene.

A polymer was synthesized in the same manner as in Synthesis Example <NUM>, except that <NUM> of <NUM>,<NUM>-dichloro-<NUM>,<NUM>,<NUM>,<NUM>-tetramethylbenzene was used instead of the p-dichlorobenzene.

A polymer was synthesized in the same manner as in Synthesis Example <NUM>, except that <NUM> of <NUM>,<NUM>-diiodo-<NUM>,<NUM>-dioctylbenzene was used instead of the p-dichlorobenzene.

In order to confirm the structures of the polymer support produced in Synthesis Example <NUM>, a <NUM>C NMR analysis was performed, and then the results thereof are shown in the following <FIG>. As in the results in the following <FIG>, it is understood that the synthesized polymer support is present as the structure as in Formula <NUM>.

For the analysis of the physical properties of the polymer support produced in Synthesis Example <NUM>, a differential scanning calorimetry (DSC) analysis was performed, and then the results thereof are shown in the following <FIG>. As a result, it is understood that the synthesized polymer support (PH) has a Tm of <NUM> and a Tc of <NUM>.

<NUM> of oleylamine and <NUM> of Pd(acac)<NUM> were mixed in an argon atmosphere and stirred at <NUM> for <NUM> hour. Thereafter, <NUM> of a borane tert-butylamine complex and <NUM> of an oleylamine mixture were put into the aforementioned mixture, and the resulting mixture was heated at <NUM> and stirred for <NUM> hour. Thereafter, <NUM> of ethanol was put into the mixture, and then a palladium cluster was obtained through centrifugation, and the obtained palladium cluster was dispersed in <NUM> of hexane and stored as a palladium-hexane solution.

<NUM> of the polymer support produced in Synthesis Example <NUM> was put into <NUM> of a hexane solution and stirred (a mixture A). <NUM> of the synthesized palladium-hexane solution and <NUM> of a hexane solution were mixed (a mixture B). The mixture B was slowly dropped onto the stirring mixture A, and then the resulting mixture was stirred for <NUM> hours. The stirred mixture was ultrasonicated for <NUM> hours, and then filtered, and dried at room temperature. The dried product was added to <NUM> of acetic acid, and the resulting mixture was stirred at <NUM> for <NUM> hours, filtered, washed with <NUM> of ethanol, and then dried at room temperature for <NUM> hours. The produced catalyst is represented by "Pd/PH".

A process was performed in the same manner as in Example <NUM>, except that the polymer support produced in Synthesis Example <NUM> was used instead of the polymer support produced in Synthesis Example <NUM>.

A process was performed in the same manner as in Example <NUM>, except that in Example <NUM>, a commercially available silica (Aldrich, <NUM>) was used instead of the polymer support produced in Synthesis Example <NUM>. The produced catalyst is represented by "Pd/SiO<NUM>".

In order to confirm the state of active metals supported on the polymer support in Examples <NUM>, a transmission electron microscope (TEM) analysis was performed, and the results thereof are shown in the following <FIG>. As in the results of the following <FIG>, it is understood that in the case of the Pd/PH sample, palladium clusters having a diameter of about <NUM> are uniformly dispersed and present.

In order to confirm the thermal stability of the polymer support-based hydrogenation catalysts in Examples <NUM> to <NUM>, the produced catalysts were subjected to thermal gravimetric analysis (TGA) in a hydrogen atmosphere, and then the results thereof are shown in the following <FIG> and <FIG>. More specifically, <FIG> and <FIG> show the change in weight of the polymer supports according to the temperature under reaction conditions using a thermal gravimetric analyzer, and are spectra illustrating the change in weight of the polymer according to the increase in temperature under a hydrogen condition. As in the results of the following <FIG> and <FIG>, it was confirmed that the polymer support was not decomposed up to about <NUM> in a hydrogen atmosphere, even though the hydrogen active metal was supported.

The activities of the supported catalysts produced in the Examples and the Comparative Example were confirmed by the following method.

A hydrogenation reaction of acetylene was performed under conditions of <NUM> atm, <NUM>, and a weight hourly space velocity (WHSV) of <NUM>C2H2 gcat-<NUM>h-<NUM> by feeding <NUM> kPa of acetylene, <NUM> kPa of ethylene, and <NUM> kPa of hydrogen- and nitrogen-based gases.

In order to analyze product components in the hydrogenation reaction, the product components were analyzed using gas chromatography. The conversion of a reactant (acetylene) and the selectivities of products (ethylene, ethane, and the like) were calculated by the following Equations <NUM> and <NUM>. <MAT> <MAT>.

The acetylene hydrogenation reaction results using the catalysts produced in the Examples and Comparative Example <NUM> are shown in the following Table <NUM> and <FIG> and <FIG>. More specifically, the following <FIG> is a view illustrating the acetylene hydrogenation reaction results of the hydrogenation catalyst, and <FIG> is a view illustrating the long-term reaction stability reaction results of the acetylene hydrogenation catalyst.

Analysis devices and analysis conditions applied in the present application are as follows.

As in the results, it can be confirmed that the catalysts produced in the Examples maintain a high ethylene selectivity for a long period of time and have a very slow inactivation degree compared to a Pd/SiO<NUM> catalyst using silica as a support in the related art.

From the experimental results using the polymer support comprising the repeating unit represented by any one of Formulae <NUM> to <NUM>, similar effects can be obtained even when a functional group such as another alkyl group and aryl group having a similar action principle is additionally bonded to a repeating unit represented by Formula <NUM>.

Therefore, a polymer support consisting of the repeating unit represented by Formula <NUM> can be applied as a support of a catalyst for a hydrogenation reaction.

Claim 1:
The use of a catalyst in a hydrogenation reaction of alkyne to alkene, the catalyst comprising:
a polymer support; and
a catalytic component supported on the polymer support,
wherein the polymer support consists of a repeating unit represented by the following Formula <NUM>:
<CHM>
in Formula <NUM>,
R1 to R4 are the same as or different from each other, and are each independently hydrogen, an alkyl group having <NUM> to <NUM> carbon atoms, or an aryl group having <NUM> to <NUM> carbon atoms, or adjacent groups are optionally bonded to each other to form a hydrocarbon ring.