Copper-based composite catalyst and method for distinguishing oxidation numbers thereof

Abstract

The present invention relates to a copper-based composite catalyst and a method for distinguishing same, the copper-based composite catalyst having a specific content of copper with respect to the surface and having a specific ratio according to a copper oxidation number. The copper-based composite catalyst according to the present invention has little strength change rate, and has excellent reactivity when used in the production of neopentyl glycol (NPG).

Description

Copper-based composite catalyst and oxidation number selection method thereof

[0001] The present invention relates to a copper-based composite catalyst and a method for selecting an oxidation number thereof.

[0002] <Cross-reference to related applications>

[0003] This application claims the benefit of Korean Patent Application No. 10-2024-0009953, filed with the Korean Intellectual Property Office on January 23, 2024, the entire contents of which are incorporated herein by reference.

[0004] Neopentyl glycol (NPG) is a white crystalline substance with a melting point of 130°C or higher. It is used as an important intermediate for various synthetic resins and is also widely used industrially as a raw material for various plastic powder coatings, synthetic lubricants, plasticizers, surfactants, and fiber processing agents.

[0005] These NPGs are typically produced by first producing hydroxypivaldehyde (HPA) through an aldol condensation reaction of isobutyraldehyde and formaldehyde, and then reacting the HPA with hydrogen in the presence of a catalyst. To achieve high yields, the process is performed under high temperature (160°C or higher) and high pressure (35 bar or higher) conditions using a copper-based composite catalyst.

[0006] However, when using a copper-based composite catalyst, the strength of the catalyst is an important factor because the reaction proceeds under high temperature and high pressure conditions. Accordingly, the industry uses a copper-based composite catalyst containing copper oxide (CuO).

[0007] Since the above copper-based composite catalyst exhibits significant differences in reaction activity depending on the copper oxidation state, it is important to determine not only the content of copper constituting the catalyst but also the compositional ratio of copper by oxidation state to control the activity of the catalyst. At this time, it is important to accurately measure the ratio of copper by oxidation state within the copper-based composite catalyst to control the compositional ratio of copper with a specific oxidation state and confirm whether a catalyst with the desired properties has been produced.

[0008] Therefore, in order to improve the catalyst properties such as stability and activity, technological development is continuously being carried out on methods to accurately measure and determine the composition ratio of copper with a specific oxidation number.

[0009] The present specification provides a copper-based composite catalyst and a method for selecting an oxidation number thereof.

[0010] One embodiment of the present specification provides a copper-based composite catalyst comprising copper in a content of 2.5 at% to 7.5 at% on the surface, wherein the copper comprises copper with an oxidation state of 0 and copper with an oxidation state of 1 in a ratio of 10% to 50% and copper with an oxidation state of 2 in a ratio of 50% to 90%, and wherein the content and ratio are obtained by the following method 1.

[0011] [Method 1]

[0012] An XPS spectrum was obtained for the surface of a copper-based composite catalyst, which includes a main peak for copper with an oxidation state of 0, a main peak for copper with an oxidation state of 1, a main peak for copper with an oxidation state of 2, and a satellite peak for copper.

[0013] Using the area of ​​the above XPS spectrum, the total copper content (at%) and the ratio (%) of copper with oxidation numbers 0 and 1 and copper with oxidation number 2 are obtained, respectively.

[0014] Another embodiment of the present specification provides a method for screening oxidation states of a copper-based composite catalyst, comprising the steps of: obtaining an XPS spectrum for the surface of a copper-based composite catalyst including a main peak for copper in oxidation state 0, a main peak for copper in oxidation state 1, a main peak for copper in oxidation state 2, and satellite peaks for copper; and calculating the total content (at%) of copper and the ratio (%) of copper in oxidation states 0 and 1 and copper in oxidation state 2, respectively, using the area of ​​the XPS spectrum.

[0015] The copper-based composite catalyst according to the present invention has high strength, almost no change in strength before and after post-treatment, almost no copper elution during storage, processing, or use, and when used in the production of neopentyl glycol (NPG), the hydrogen consumption reaction rate is very fast and the reactivity is excellent.

[0016] The oxidation number selection method of a copper-based composite catalyst according to the present invention can accurately measure the content of a specific oxidation number in a copper-based composite catalyst, and can also calculate the content of a trace amount of oxidation number.

[0017] Figures 1 to 3 are diagrams of XPS spectra of copper-based composite catalysts (in order, Examples 1-1 to 1-3) manufactured according to a selection method according to the embodiment of the present specification.

[0018] FIG. 4 and FIG. 5 are diagrams of XPS spectra of copper-based composite catalysts (Comparative Examples 1-1 and 1-2, respectively) in comparison with the embodiment of the present specification.

[0019] FIGS. 6 to 9 are diagrams of XPS spectra of a copper-based composite catalyst according to an embodiment of the present specification (Example 2-3 (FIG. 8)) and a copper-based composite catalyst in comparison with an embodiment of the present specification (Comparative Examples 2-2 (FIG. 7), 2-3 (FIG. 7) and Comparative Example 2-4 (FIG. 9)).

[0020] Hereinafter, the present invention will be described in detail so that those skilled in the art can easily implement it. However, the present invention can be implemented in various different forms and is not limited to the configuration described herein.

[0021] In this specification, when a part is said to 'include' a certain component, this means that it may include other components, rather than excluding other components, unless specifically stated otherwise.

[0022] In this specification, 'p to q' means 'p or more and q or less'.

[0023] In this specification, Cu(0) represents copper with an oxidation number of 0, Cu(I) represents copper with an oxidation number of 1, and Cu(II) represents copper with an oxidation number of 2.

[0024] In this specification, Cu 2p on XPS spectrum 3 / 2 The main peak refers to a shape in which the intensity increases rapidly (high peak shape) within the range of binding energy (BE) from 928.0 eV to 939.0 eV within the 2p spectrum of Cu, and the satellite peak refers to a shape in which the intensity increases gradually (low hill shape) within the range of binding energy (BE) from 939.0 eV to 950.0 eV (see Figs. 1 to 9).

[0025] In this specification, the main peak for copper with oxidation number 0, the main peak for copper with oxidation number 1, and the main peak for copper with oxidation number 2 may be expressed as Cu(0) Main Peak, Cu(I) Main Peak, and Cu(II) Main Peak, respectively.

[0026] In this specification, “strength” refers to the measurement of the detachment strength of the catalyst, and specifically, it may mean the value calculated from the average of 20 maximum detachment strengths at the initial collapse point using SHIMPO’s FGN-50B.

[0027] In addition, in describing the present invention, detailed descriptions of related known technologies that may unnecessarily obscure the gist of the present invention will be omitted.

[0028] Copper-based composite catalyst

[0029] One embodiment of the present specification provides a copper-based composite catalyst comprising copper in a content of 2.5 at% to 7.5 at% on the surface, wherein the copper comprises copper with an oxidation state of 0 and copper with an oxidation state of 1 in a ratio of 10% to 50% and copper with an oxidation state of 2 in a ratio of 50% to 90%, and wherein the content and ratio are obtained by the following method 1.

[0030] [Method 1]

[0031] An XPS spectrum was obtained for the surface of a copper-based composite catalyst, which includes a main peak for copper with an oxidation state of 0, a main peak for copper with an oxidation state of 1, a main peak for copper with an oxidation state of 2, and a satellite peak for copper.

[0032] Using the area of ​​the above XPS spectrum, the total content (at%) of copper and the ratio (%) of copper with oxidation numbers 0 and 1 and copper with oxidation number 2 are obtained, respectively.

[0033] A copper-based composite catalyst satisfying the above content (at%) and ratio (%) has high strength, almost no change in strength before and after post-treatment, thus improving stability, and when used in the production of neopentyl glycol (NPG), has a very fast hydrogen consumption reaction rate and excellent reactivity.

[0034] In this specification, the content (at%) may be expressed as an atomic concentration.

[0035] In this specification, the main peak and satellite peak according to each oxidation number are characterized by being calculated as the area of ​​the XPS spectrum, and the oxidation number is selected and / or quantified using the area for each peak according to the method specifically described in this specification.

[0036] In one embodiment of the present specification, the ratio (%) of copper with oxidation numbers 0 and 1 can be calculated by the following equation 1, and the ratio (%) of copper with oxidation number 2 can be calculated by the following equation 2.

[0037] [Formula 1]

[0038]

[0039] [Formula 2]

[0040]

[0041] In the above equations 1 and 2,

[0042] Cu(0), Cu(I) and Cu(II) represent copper with oxidation number 0, copper with oxidation number 1 and copper with oxidation number 2, respectively.

[0043] and satisfy,

[0044] A1 is the sum of the total area of ​​the Cu(0) main peak and the total area of ​​the Cu(I) main peak calculated through the XPS spectrum,

[0045] A2 is the total area of ​​the Cu(II) main peak calculated through the XPS spectrum,

[0046] B is the total area of ​​satellite peaks for Cu(II) calculated through XPS spectra,

[0047] As / Bs is Cu 2p of Cu(II) 3 / 2 It refers to the area ratio of the main peak / satellite peak.

[0048] In this specification, the ratio according to the oxidation number of copper occupying the copper-based composite catalyst is a value obtained by the above formulas 1 and 2, respectively. Specifically, the ratio (%) for copper with oxidation numbers 0 and 1 can be obtained by calculating by the above formula 1, and the ratio (%) for copper with oxidation number 2 can be obtained by calculating by the above formula 2.

[0049] The copper-based composite catalyst according to one embodiment of the present disclosure may be further processed by methods known in the art, as long as they do not depart from the scope of the present invention. Examples of such further processing include hydrothermal treatment.

[0050] In this specification, hydrothermal treatment is one of the post-treatments for controlling the strength of the catalyst, etc., and the hydrothermal treatment method is a method known in the art and is not particularly limited as long as it does not deviate from the present invention.

[0051] In one embodiment of the present specification, the surface may mean a region having a depth of 0 nm or more and 10 nm or less in the center direction at the interface of the copper-based composite catalyst in contact with the atmosphere.

[0052] In one embodiment of the present specification, the area of ​​the XPS spectrum may mean the total area (first area value) of the main peak for copper with oxidation number 0 and the main peak for copper with oxidation number 1 from the XPS spectrum, the total area (second area value) of the main peak for copper with oxidation number 2, and the total area (third area value) of the satellite peak for copper.

[0053] In one embodiment of the present specification, the first to third area values ​​can be measured by setting a background using the Shirley method and performing fitting processing using the Lorentzian / Gaussian (L / G) function and the FWHM (Full Width Half Maximum).

[0054] In one embodiment of the present specification, the copper-based composite catalyst may include at least one of copper oxide and copper structure.

[0055] In this specification, copper oxide can be expressed as Cu-O, and the copper structure is (The upper limit is not set as long as n is an integer greater than or equal to 1, and it can be expressed as A=Al, Si, etc.)

[0056] In this specification, copper oxide and copper structure are catalyst structures containing copper, and mean substances having catalytic activity and playing a major role in catalytic reactions.

[0057] In one embodiment of the present specification, the copper-based composite catalyst may further include a carrier.

[0058] In this specification, the carrier is a material that disperses and maintains the copper oxide and structure on its surface, and representative examples thereof include silica and alumina, but zeolite, titania, magnesia, zirconia, carbon, diatomaceous earth, etc. may also be used as the carrier. As long as it is a method known in the art and does not deviate from the present invention, there is no particular limitation thereon.

[0059] A copper-based composite catalyst according to one embodiment of the present disclosure may be a catalyst for producing neopentyl glycol. Accordingly, when the copper-based composite catalyst is used in the production of neopentyl glycol, reactivity such as reaction efficiency is improved, and strength is improved while there is no change in strength, thereby improving the stability of the catalyst structure itself.

[0060] <Method for Selecting Oxidation Numbers of Copper-Based Composite Catalysts>

[0061] One embodiment of the present specification provides a method for selecting an oxidation state of a copper-based composite catalyst using X-ray photoelectron spectroscopy (XPS).

[0062] More specifically, the oxidation number selection method of a copper-based composite catalyst according to the present specification is characterized by calculating the total content (at%) of copper and the ratio according to the oxidation number of copper using the area of ​​the XPS spectrum for the copper-based composite catalyst including the main peak for copper with oxidation number 0, the main peak for copper with oxidation number 1, the main peak for copper with oxidation number 2, and the satellite peak for copper.

[0063] The oxidation number selection method of the copper-based composite catalyst according to one embodiment of the present specification is applicable to a copper-based composite catalyst that includes a copper content of 0.1 at% or more on the surface.

[0064] Within the above range, the oxidation number selection method of the copper-based composite catalyst according to the present invention can be applied.

[0065] Due to the XPS detection limit, the oxidation state selection method of the copper-based composite catalyst according to the present invention cannot be applied when the total content of copper in oxidation state 0 and copper in oxidation state 1 is less than 0.05 at%. In addition, when the total content of copper in oxidation state 0 and copper in oxidation state 1 is 100 at%, there is no reason to select the copper oxidation state content as it is related to copper metal or Cu2O.

[0066] A copper composite catalyst according to an embodiment of the present specification may use a technique commonly used in the relevant field, except that the contents of copper [Cu(0)] with oxidation number 0, copper [Cu(I)] with oxidation number 1, and copper [Cu(II)] with oxidation number 2, measured by an oxidation number selection method of the copper composite catalyst, satisfy the above range.

[0067] The oxidation number selection method of the copper-based composite catalyst according to the present specification is such that the ratio (%) of copper with oxidation numbers 0 and 1 can be calculated by the above equation 1, and the ratio (%) of copper with oxidation number 2 can be calculated by the above equation 2. The contents of equations 1 and 2 can be equally applied to this paragraph as described above with respect to the copper-based composite catalyst.

[0068] The oxidation state selection method of a copper-based composite catalyst according to one embodiment of the present disclosure utilizes satellite peaks as well as the main peak to more accurately measure the content of a specific oxidation state. Furthermore, it has the advantage of being able to accurately determine the content of copper at a specific desired oxidation state within a copper-based composite catalyst, even within a small amount.

[0069] In one embodiment of the present specification, the step of deriving an XPS spectrum of the copper-based composite catalyst may include a step of deriving an XPS spectrum of the copper-based composite catalyst by X-ray photoelectron spectroscopy (XPS) under conditions of a vacuum atmosphere, a measurement range of 925 eV to 970 eV, and a pass energy of 50 eV; and a step of correcting a peak of the XPS spectrum.

[0070] In this specification, the copper-based composite catalyst can be expressed as an XPS derivation condition with a pass energy condition of 50 eV in a measurement range of 925 eV to 970 eV in a vacuum atmosphere.

[0071] That is, after deriving the first XPS spectrum (XPS spectrum before correction) of the copper-based composite catalyst by X-ray photoelectron spectroscopy (XPS) under a pass energy condition of 50 eV in a measurement range of 925 eV to 970 eV in a vacuum atmosphere, the peak of the XPS spectrum can be corrected to derive the second XPS spectrum (XPS spectrum after correction) which is the analysis target of the present invention.

[0072] In one embodiment of the present specification, the copper-based composite catalyst may be manufactured as a sample of a circular pellet having a diameter of 2 mm and a thickness of 1 mm, and an XPS spectrum may be derived from the sample using Al k-alpha X-ray having a size of 400 ㎛ x 800 ㎛ under the XPS derivation conditions. That is, when analyzing the XPS spectrum, monochromatic Al Kα (1486.6 eV) may be used as an X-ray source, and Shirley Peak Background, ALTHERMO1 Sensitivity factor, and TPP-2M Energy compensation factor may be applied. In addition, the content of elements present on the surface of the copper-based composite catalyst (atomic percent, at%, based on the total atomic weight of elements present on the surface) may be determined using Avantage software.

[0073] In one embodiment of the present specification, the step of correcting the peak of the XPS spectrum may be to fix the CC binding energy for graphite of the carbon 1s spectrum (C 1s spectrum) to a certain energy, and correct the binding energy for the main peak for copper based on the energy of the certain energy. The energy of the certain energy may be 284 eV to 285 eV, and most preferably 284.8 eV.

[0074] In one embodiment of the present specification, correction based on the energy of a certain size may mean correction of the binding energy of the Cu(I) Main Peak.

[0075] Through the above process, the range of peak binding energy for obtaining the Cu(II) peak area can be set to 933.3 eV to 936.0 eV, and the range of peak binding energy for obtaining the peak areas of Cu(0) and Cu(I) can be set to 932.0 eV to 932.8 eV.

[0076] By setting the peak binding energy range within the above range, a pure peak can be identified. That is, by identifying a pure peak unaffected by other factors, the oxidation number content of the copper-based composite catalyst can be selected, thereby increasing the accuracy of the results.

[0077] In one embodiment of the present specification, the step of calculating the total content (at%) of copper and the ratio (%) of copper with oxidation numbers 0 and 1 and copper with oxidation number 2 using the area of ​​the XPS spectrum,

[0078] A step of deriving the total content of copper on the surface of the copper-based composite catalyst from the XPS spectrum;

[0079] A step of deriving a first area value as the total area of ​​the main peak for copper with oxidation number 0 and the main peak for copper with oxidation number 1 on the surface of the copper-based composite catalyst from the XPS spectrum;

[0080] A step of deriving a second area value as the total area of ​​the main peak for copper with oxidation number 2 on the surface of the copper-based composite catalyst from the XPS spectrum;

[0081] A step of deriving a third area value as the total area of ​​the satellite peak for copper on the surface of the copper-based composite catalyst from the XPS spectrum; and

[0082] It may include a step of deriving the content (at%) of copper with oxidation numbers 0 and 1 and the content (at%) of copper with oxidation number 2, respectively, through the following equations 4 and 5.

[0083] [Formula 4]

[0084]

[0085] [Formula 5]

[0086]

[0087] In the above equations 4 and 5,

[0088] at%(Cu(0)+Cu(I)) is the total content of copper with oxidation number 0 and copper with oxidation number 1 in the copper-based composite catalyst,

[0089] at% Cu(II) is the total content of copper in oxidation state 2 in the copper-based composite catalyst,

[0090] % (Cu(0) + Cu(I)) is the ratio (%) of copper with oxidation numbers 0 and 1 calculated by the above equation 1,

[0091] % Cu(II) refers to the ratio (%) of copper with oxidation number 2 calculated by the above equation 2.

[0092] In this specification, the peaks of Cu(0) and Cu(I) can be expressed as Cu(0) + Cu(I) Peak. For reference, Cu(0) + Cu(I) Peak can mean the main peaks for Cu(0) and Cu(I).

[0093] In one embodiment of the present specification, the step of deriving the first area value may include the step of finding both the main peak for copper with an oxidation number of 0 and the main peak for copper with an oxidation number of 1 from the XPS spectrum; and the step of calculating the area values ​​of the main peak for copper with an oxidation number of 0 and the main peak for copper with an oxidation number of 1, respectively, and then adding all of the calculated area values.

[0094] In the case of the above Cu(0) Main Peak and Cu(I) Main Peak, since each may appear more than once in the XPS spectrum, both the Cu(0) Main Peak and the Cu(I) Main Peak must be found for accurate measurement. In addition, since the Cu(0) Main Peak and the Cu(I) Main Peak have parts that are difficult to distinguish in the spectrum, the total area value of the Cu(0) Main Peak and the Cu(I) Main Peak is obtained. In the case of Fig. 1, there is one Cu(0) Main Peak or Cu(I) Main Peak (see ① in Fig. 1), but this is an example, and there may be multiple Cu(0) Main Peaks or Cu(I) Main Peaks. The first area value corresponds to the area value of A1 in Fig. 1.

[0095] In one embodiment of the present specification, the step of deriving the second area value may include the steps of finding all main peaks for copper with an oxidation number of 2 from the XPS spectrum; and the steps of calculating the area values ​​of the main peaks for copper with an oxidation number of 2, and then adding all the calculated area values. Since the Cu(II) Main Peak may appear more than once in the XPS spectrum, accurate measurement is possible only when all Cu(II) Main Peaks are found. That is, as can be confirmed in FIG. 1, since multiple Cu(II) Main Peaks may exist (see ② and ③ in FIG. 1), accurate measurement is possible only when all Cu(II) Main Peaks are found in the XPS spectrum. The second area value corresponds to the area value of A2 in FIG. 1.

[0096] In one embodiment of the present specification, the step of deriving the third area value may include the steps of finding all satellite peaks for copper from the XPS spectrum; and the steps of calculating the area values ​​of the satellite peaks for copper, and then adding all the calculated area values. Since more than one satellite peak may appear in the XPS spectrum, accurate measurement is possible only when all satellite peaks are found. That is, as can be confirmed in Fig. 1, since there may be multiple Cu(II) Main Peaks (see ④ and ⑤ in Fig. 1), accurate measurement is possible only when all satellite peaks for the XPS spectrum are found. The third area value corresponds to the area value of B in Fig. 1.

[0097] In one embodiment of the present specification, the satellite peak may be a satellite peak for copper in oxidation state 2. This may be expressed as a Cu(II) satellite peak. That is, the Cu(II) satellite peak may refer to a satellite peak for copper in oxidation state 2 found in the XPS spectrum (secondary spectrum) after the correction.

[0098] A method for selecting the oxidation state of a copper-based composite catalyst according to one embodiment of the present disclosure utilizes not only the main peak but also satellite peaks. Therefore, clearly identifying satellite peaks is crucial for increasing the accuracy of measurement results.

[0099] In one embodiment of the present specification, As / Bs may be 1.5 to 2.1.

[0100] In one embodiment of the present specification, the copper-based composite catalyst may include at least one of copper oxide and a copper structure, and may optionally further include a carrier. Details regarding this may be equally applied to the description of the copper-based composite catalyst described above in this paragraph.

[0101] For example, the copper composite catalyst may include a Cu-O-Si catalyst, a Cu-O-Al catalyst, a Cu-O-Si-Al catalyst, etc.

[0102] In addition, the Cu-O-Si catalyst is a catalyst including copper oxide (Cu-O) and a carrier (silica), and examples thereof include CuO / SiO2, CuO / BaO / SiO2, CuO / ZnO / SiO2, CuO / BaO / SiO2, CuO / ZnO / SiO2, CuO / MnO / SiO2, CuO / Cr2O3 / SiO2, etc., and examples thereof include copper phyllosilicate (…O-Si-O-Cu-O-Si-O-Cu-O…) as a copper-silicate structure catalyst.

[0103] In addition, the Cu-O-Al catalyst may be a catalyst including copper oxide and a carrier (alumina), for example, CuO / Al2O3, and a copper-aluminate structure catalyst may be a catalyst including Copper aluminate (…O-Al-O-Cu-O-Al-O-Cu-O…).

[0104] In addition, CuO / Al2O3 / SiO2 can be cited as an example of a catalyst including copper oxide and a carrier (alumina, silica) as the Cu-O-Si-Al system.

[0105] In addition, when the copper-based composite catalyst further includes a carrier, CuO / SiO2 catalyst, CuO / Al2O3 catalyst, CuO x / SiO y (0 ≤ x < 1, 0 ≤ y < 2) and CuOx / AlOy(0 ≤ x < 1, 0 ≤y < 1.5).

[0106] The above-mentioned copper-based composite catalysts are examples and are not limited thereto.

[0107] The copper-based composite catalyst manufactured according to the present invention may be a catalyst for manufacturing neopentyl glycol. In this case, in one embodiment of the present specification, the method for manufacturing neopentyl glycol may utilize any method known in the art, except that the copper-based composite catalyst according to the present invention is used.

[0108] More specifically, one embodiment of the present specification provides a method for producing neopentyl glycol, comprising a step of introducing a hydroxypivaldehyde (HPA) solution and hydrogen into a hydrogenation reactor to perform a hydrogenation reaction, wherein the hydrogenation reactor includes a copper-based composite catalyst according to the present invention.

[0109] For example, the hydrogenation reactor may be a fixed bed reactor (FBR) filled with the copper-based composite catalyst (catalyst for producing neopentyl glycol), in which case there is no need for separation of the catalyst and the reaction product, the reaction temperature and reaction pressure can be lowered compared to before, so operation is stable and economical, and catalyst replacement work is easy, and the reactor size can be reduced, so there is the effect of greatly reducing investment costs.

[0110] In one embodiment of the present specification, the hydroxypivaldehyde solution may include 50 to 80 wt% of hydroxypivaldehyde, 1 to 5 wt% of neopentyl glycol, 15 to 35 wt% of alcohol, and 1 to 10 wt% of water, in which case the heat of reaction can be minimized without lowering the reactivity, thereby having the effect of suppressing the production of by-products.

[0111] In addition, in one embodiment of the present specification, the hydrogenation reaction may be carried out at a reaction temperature of 100°C to 250°C, preferably 100°C to 200°C, and more preferably 100°C to 180°C.

[0112] Additionally, in one embodiment of the present specification, the hydrogenation reaction may have a reaction pressure of 35 bar or more. The reaction pressure refers to a measurement pressure.

[0113] When a catalyst for producing neopentyl glycol according to one embodiment of the present specification is applied in the production of neopentyl glycol, the problem of leaching of catalyst components (e.g., copper components) in the neopentyl glycol solution produced can be prevented.

[0114] Therefore, when a catalyst for producing neopentyl glycol according to one embodiment of the present specification is applied in the production of neopentyl glycol, a purification process due to elution of a catalyst component (e.g., a copper component) is not required, and the catalyst life is extended, thereby obtaining the effect of reducing the manufacturing cost.

[0115] Hereinafter, the present invention will be described in detail using examples. However, the examples according to the present invention may be modified in various ways, and the scope of the present invention is not limited to the examples described below. The examples of the present invention are provided to more fully explain the present invention to those of ordinary skill in the art.

[0116] Experimental Example 1. Evaluation of a method for selecting oxidation numbers of copper-based composite catalysts.

[0117] <Example 1-1>

[0118] As described in Table 1 below, a copper-based composite catalyst of the Cu-O-Si system was prepared through the following process. Co-precipitation of Cu nitrate, silica sol, and an alkaline precipitant was used to obtain a precipitate powder. The Cu / Si wt% ratio introduced was 30:70 = 0.43.

[0119] Afterwards, dried powder was obtained through filtration and rinsing and drying processes.

[0120] To analyze the Cu oxidation number ratio on the catalyst surface, a Cu-O-Si copper composite catalyst sample was manufactured in the form of a circular pellet with a diameter of 2 mm and a thickness of 1 mm, and subjected to a drying / calcination process.

[0121] The above sample was placed in an XPS (X-ray Photoelectron Spectroscopy) analysis device (model name / manufacturer: Nexsa / Thermoscientific) and placed in a vacuum atmosphere (~10 -7The copper 2p spectrum (Cu 2p spectrum) was initially derived by measuring the Al k-alpha x-ray at 1486.6 eV at 10 torr, with an x-ray size of 400 ㎛ x 800 ㎛, in the measurement range of 925 eV to 970 eV, and a pass energy of 50 eV. Then, the binding energy of the derived spectrum was corrected to match the standard of the graphite C-C binding energy of 284.8 eV in the carbon 1s spectrum, thereby deriving the XPS spectrum of Fig. 1.

[0122] In the XPS spectrum above, the background is set using the Shirley method, and the first area value (A1) of the Cu(0) Main Peak representing copper with oxidation number 0 or the Cu(I) Main Peak representing copper with oxidation number 1 is obtained through fitting using the Lorentzian / Gaussian (L / G) function and the FWHM (Full Width Half Maximum). The second area value (A2), which is the total area of ​​the Cu(II) main peak, and the third area value (B) of the Cu(II) Satellite Peak, which represents the satellite peak for copper with oxidation number 2, were calculated.

[0123] The specific Lorentzian / Gaussian (L / G) function ratio was 70 / 30, and the FWHM fit parameter was 0.5:3.5.

[0124] The derivation of XPS spectra, background setting, and fitting processing were performed using the Avantage software program.

[0125] Next, after obtaining the first to third area values, the ratio of copper with oxidation number 2 in the copper-based composite catalyst of Manufacturing Example 1 was calculated using Equation 2 below. Then, the ratio of copper with oxidation number 0 and copper with oxidation number 1 was calculated using Equation 1.

[0126] The symbols of the above formulas 1 and 2 mean as follows, and As / Bs is the known CuO average value of 1.89, since the sample of Example 1-1 used above is a Cu-O-Si catalyst and contains a Cu-O bond.

[0127] [Formula 1]

[0128]

[0129] [Formula 2]

[0130]

[0131] In the above equations 1 and 2,

[0132] Cu(0), Cu(I) and Cu(II) represent copper with oxidation number 0, copper with oxidation number 1 and copper with oxidation number 2, respectively.

[0133] and satisfy,

[0134] A1 is the sum of the total area of ​​the Cu(0) main peak and the total area of ​​the Cu(I) main peak calculated through the XPS spectrum,

[0135] A2 is the total area of ​​the Cu(II) main peak calculated through the XPS spectrum,

[0136] B is the total area of ​​satellite peaks for Cu(II) calculated through XPS spectra,

[0137] As / Bs is Cu 2p of Cu(II) 3 / 2 It refers to the area ratio of the main peak / satellite peak.

[0138] The total content of copper with oxidation number 0 and copper with oxidation number 1 and the total content of copper with oxidation number 2 on the surface of the copper-based composite catalyst of Example 1-1 were calculated using the copper content (at%) measured by XPS and the ratio values ​​according to the copper oxidation number calculated from Equations 1 and 2 above, using Equations 4 and 5 below. The symbols in Equations 4 and 5 below mean as follows, and the resulting values ​​are shown in Table 1 below.

[0139] [Formula 4]

[0140]

[0141] [Formula 5]

[0142]

[0143] In the above equations 4 and 5,

[0144] at%(Cu(0)+Cu(I)) is the total content of copper with oxidation number 0 and copper with oxidation number 1 in the copper-based composite catalyst,

[0145] at% Cu(II) is the total content of copper in oxidation state 2 in the copper-based composite catalyst,

[0146] % (Cu(0) + Cu(I)) is the ratio (%) of copper with oxidation numbers 0 and 1 calculated by the above equation 1,

[0147] % Cu(II) refers to the ratio (%) of copper with oxidation number 2 calculated by the above equation 2.

[0148] <Examples 1-2 and 1-3>

[0149] The Cu / Si wt% ratio introduced was 30:70 = 0.43, and the total content of copper with oxidation number 0 and copper with oxidation number 1 and the total content of copper with oxidation number 2 on the surface of the copper-based composite catalysts of Examples 1-2 and 1-3 were calculated in the same manner as in Example 1-1.

[0150] The resulting values ​​are shown in Table 1 below.

[0151] Additionally, the XPS spectra of Examples 1-2 and 1-3 are as shown in FIGS. 2 and 3, respectively.

[0152] <Comparative Example 1-1>

[0153] An XPS spectrum was derived using the same copper-based composite catalyst as in Example 1-1 using the same method as in Example 1-1. However, unlike Example 1-1, the background was set and fitting was performed without considering the satellite peak.

[0154] As a result, as shown in Fig. 4, there is no area (A1) of the Cu(0) and Cu(I) main peaks representing copper with oxidation number 0 or 1 on the surface, and no area (B) of the satellite peaks representing copper with oxidation number 2. It was confirmed that the fitting was in the form of showing only the total area (A2) of the Cu(II) main peak. That is, in the case of Comparative Example 1-1, even though the same catalyst as Example 1 was used, the ratio of copper with oxidation number 0 and copper with oxidation number 1 could not be measured.

[0155] Next, the ratio of copper with oxidation number 2 was measured from the fitting results shown in Fig. 4.

[0156] The results are shown in Table 1 below.

[0157] <Comparative Example 1-2>

[0158] Except that the same copper-based composite catalyst as in Example 1-2 was used, the copper oxidation number content in the copper-based composite catalyst was measured using the same method as in Comparative Example 1-1.

[0159] That is, in Comparative Example 1-2, as shown in FIG. 5, there was no area (A1) of the Cu(0) and Cu(I) main peaks and no area (B) of the satellite peaks indicating copper with oxidation number 0 or 1, so the ratio of copper with oxidation number 0 and copper with oxidation number 1 could not be measured, and the ratio of copper with oxidation number 2 was measured from the fitting results shown in FIG. 5. The results are shown in Table 1 below.

[0160] Cu oxidation number ratio (%) / Cu oxidation number content (at %) Cu-O-Si catalyst Example 1-1 Example 1-2 Example 1-3 Comparative Example 1-1 Comparative Example 1-2 Cu(0), Cu(I)18 / 0.677 / 0.5727 / 1.00 / 0.00 / 0.0 Cu(II)82 / 3.0393 / 7.5373 / 2.8100 / 3.7100 / 8.1

[0161] From the results in Table 1 above, it was confirmed that in the case of following the selection method according to the present invention (Examples 1-1 to 1-3), more accurate values ​​can be obtained for the content according to the copper oxidation number than in the case of not following the selection method according to the present invention (Comparative Examples 1-1 and 1-2).

[0162] That is, when the satellite peak is not considered, the area (A1) of the Cu(0) and Cu(I) main peaks representing copper in oxidation state 0 or 1 does not exist, and therefore, no results can be derived, and therefore, the content of copper in oxidation state 0 or 1 could not be determined. In addition, since the content of copper in oxidation state 0 or 1 could not be determined, the content of copper in oxidation state 2 was also measured inaccurately.

[0163] Experimental Example 2. Evaluation of the properties of a copper-based composite catalyst.

[0164] <Examples 2-1 and 2-2>

[0165] The Cu-O-Si catalysts of Examples 1-1 and 1-3 were used as copper composite catalysts for property evaluation.

[0166] <Example 2-3>

[0167] A Cu-O-Al catalyst was used as a copper-based composite catalyst for property evaluation, and the selection method described in Example 1-1 was applied to the preparation of the catalyst.

[0168] In addition, except that Cu nitrate, Alumina sol, and an alkaline precipitant were added using a co-precipitation method so that the Cu / Al weight percent ratio was 30:70 to manufacture a precipitate powder, the filtration and rinsing, drying, manufacturing in the form of circular pellets, and drying / calcination processes were the same as those described in Example 1-1 to manufacture a copper-based composite catalyst.

[0169] <Comparative Example 2-1>

[0170] The Cu-O-Si catalyst of Example 1-2 was used as a copper-based composite catalyst for property evaluation.

[0171] <Comparative Example 2-2>

[0172] A Cu-O-Al catalyst was prepared in the same manner as described in Example 2-3, except that the precipitate powder was prepared by adding Cu / Al at a weight percent ratio of 15:85.

[0173] <Comparative Example 2-3>

[0174] A Cu-O-Al catalyst was prepared in the same manner as described in Example 2-3, except that precipitated powder was prepared by adding Cu / Al weight percent ratio of 15:85 and hydrothermal treatment at 150°C was added to increase the ratio (%) of Cu(II).

[0175] <Comparative Example 2-4>

[0176] A Cu-O-Al catalyst was prepared in the same manner as described in Example 2-3, except that a hydrothermal treatment at 150°C was added to increase the proportion (%) of Cu(II).

[0177] As described in Table 2 below, the Cu-O-Al copper composite catalyst was calculated in the same manner as Example 1-1 in terms of the contents of copper with oxidation number 0, copper with oxidation number 1, and copper with oxidation number 2, and the resulting values ​​are as follows. In addition, the XPS spectra for Comparative Examples 2-2 and 2-3, Example 2-3, and Comparative Example 2-4 are as shown in FIGS. 6 to 9, respectively.

[0178] Cu oxidation number ratio (%) / Cu oxidation number content (at %) Cu-O-Al type catalyst Added Cu / Al wt% ratio = 15 / 85 Added Cu / Al wt% ratio = 30 / 70 Comparative Example 2-2 Comparative Example 2-3 Example 2-3 Comparative Example 2-4 Cu(0), Cu(I) 5 3 / 1.217 / 0.213 / 0.88 / 0.1 Cu(II) 4 7 / 1.083 / 0.987 / 5.892 / 1.0

[0179] Experimental Example 2-1. Evaluation of Hydrogen Consumption Rate (Property Evaluation 1)

[0180] Using a Buchi autoclave, 100 g of the feed solution (HPA:2-EH=1:4) for the production of neopentyl glycol (NPG) and 3 cc of the copper-based composite catalysts of Examples 2-1 to 2-3 and Comparative Examples 2-1 and 2-2 were each placed in a reactor, and after reduction treatment with hydrogen at 180°C, the rate of hydrogen consumption (ml / min) was maintained at 30 bar and 115°C. . g cat ) was measured and evaluated.

[0181] At this time, the hydrogen consumption rate measured in Example 2-1 was set as 100%, and the hydrogen consumption rates of Examples 2-2, 2-3, and Comparative Examples 2-1 and 2-2 were converted to a percentage (referred to as relative hydrogen consumption rate) compared to Example 2-1 and compared and evaluated. The evaluation results are as shown in Table 3 below.

[0182] Catalyst type classificationCopper content (at%, surface)Proportion of copper with oxidation number 0 and 1 (%)Proportion of copper with oxidation number 2 (%)Relative hydrogen consumption rate (unit: %)Cu-O-Si type catalystExample 2-13.71882100Comparative example 2-18.179386Example 2-23.82773102Cu-O-Al type catalystComparative example 2-22.2534757Example 2-36.6138791

[0183] According to Table 3 above, the copper composite catalysts according to the present invention (Examples 2-1 to 2-3) comprising copper in a content of 2.5 at% to 7.5 at% on the surface, copper with an oxidation state of 0 and copper with an oxidation state of 1 in a ratio of 10% to 50%, and copper with an oxidation state of 2 in a ratio of 50% to 90% have a hydrogen consumption rate exceeding 90%, whereas the hydrogen consumption rate is lower than 90% compared to the copper composite catalysts that do not satisfy the above content (at%) and ratio (%), confirming that the above content and ratio are significant components for the reactivity of the copper composite catalyst. In particular, when comparing the examples and comparative examples of the same series of catalysts, the difference was more remarkable.

[0184] Experimental Example 2-2. Strength Reduction Rate Evaluation (Material Property Evaluation 2)

[0185] <Comparative Example 3-1>

[0186] The copper-based composite catalyst before the hydrothermal treatment of Comparative Example 2-2 and the copper-based composite catalyst after the hydrothermal treatment of Comparative Example 2-3 were compared.

[0187] The strength of the catalyst (unit: N) before and after hydrothermal treatment was evaluated. Specifically, the hydrothermal treatment was performed by putting 100 ml of water (H2O) and the copper-based composite catalyst before hydrothermal treatment into an autoclave and maintaining the temperature at 150°C for 3 hours. The pressure inside the autoclave was set to a high pressure between 10 and 20 bar. The results of the strength reduction rate evaluation are shown in Table 4 below, and the strength reduction rate was calculated as a percentage (%) of ‘(strength measured before hydrothermal treatment - strength measured after hydrothermal treatment) / strength before hydrothermal treatment.’

[0188] <Example 3-1>

[0189] Except for comparing the copper-based composite catalyst before hydrothermal treatment of Example 2-3 and the copper-based composite catalyst after hydrothermal treatment of Comparative Example 2-4, the strength reduction rate was evaluated in the same manner as in Comparative Example 3-1, and the results are as shown in Table 4 below.

[0190] Strength reduction rate (%) after pretreatment of the pretreatment series (comparative example 3-1132596%), practical example 3-162620%

[0191] According to Table 4 above, it can be confirmed that the copper-based composite catalyst according to the present invention (Example 2-3) before hydrothermal treatment, which includes copper in a content of 2.5 at% to 7.5 at% on the surface, copper with an oxidation number of 0 and copper with an oxidation number of 1 in a ratio of 10% to 50%, and copper with an oxidation number of 2 in a ratio of 50% to 90%, has a strength reduction rate of 0% after hydrothermal treatment (see Example 3-1), whereas the copper-based composite catalyst before hydrothermal treatment, which does not satisfy the above content (at%) and ratio (%), has a strength reduction rate of 96% (see Comparative Example 3-1).

Claims

1. Contains copper in a content of 2.5 at% to 7.5 at% on the surface, The copper comprises copper with an oxidation number of 0 and copper with an oxidation number of 1 in a ratio of 10% to 50% and copper with an oxidation number of 2 in a ratio of 50% to 90%, The above content and ratio are obtained by the following method 1: Copper-based composite catalyst: [Method 1] An XPS spectrum was obtained for the surface of a copper-based composite catalyst, which includes a main peak for copper with an oxidation state of 0, a main peak for copper with an oxidation state of 1, a main peak for copper with an oxidation state of 2, and a satellite peak for copper. Using the area of the above XPS spectrum, the total content (at%) of copper and the ratio (%) of copper with oxidation numbers 0 and 1 and copper with oxidation number 2 are obtained, respectively.

2. In claim 1, The ratio (%) of copper with oxidation numbers 0 and 1 is calculated by the following equation 1, The ratio (%) of copper with oxidation number 2 above is calculated by the following equation 2: Copper-based composite catalyst: [Formula 1] [Formula 2] In the above equations 1 and 2, Cu(0), Cu(I) and Cu(II) represent copper with oxidation number 0, copper with oxidation number 1 and copper with oxidation number 2, respectively. and satisfy, A1 is the sum of the total area of the Cu(0) main peak calculated through the XPS spectrum and the total area of the main peak for Cu(I), A2 is the total area of the Cu(II) main peak calculated through the XPS spectrum, B is the total area of satellite peaks for Cu(II) calculated through XPS spectra, As / Bs is Cu 2p of Cu(II) 3 / 2 It refers to the area ratio of the main peak / satellite peak.

3. In claim 1, A copper composite catalyst, wherein the surface refers to a region having a depth of 0 nm or more and 10 nm or less in the center direction at the interface of the copper composite catalyst in contact with the atmosphere.

4. In claim 1, The copper-based composite catalyst is a copper-based composite catalyst comprising at least one of copper oxide and copper structure.

5. In claim 4, A copper-based composite catalyst further comprising a carrier.

6. A step of obtaining an XPS spectrum for the surface of a copper-based composite catalyst including a main peak for copper with an oxidation number of 0, a main peak for copper with an oxidation number of 1, a main peak for copper with an oxidation number of 2, and a satellite peak for copper; and A step of calculating the total content (at%) of copper and the ratio (%) of copper with oxidation numbers 0 and 1 and copper with oxidation number 2, respectively, using the area of the above XPS spectrum. A method for selecting oxidation numbers of a copper-based composite catalyst including:

7. In claim 6, The ratio (%) of copper with oxidation numbers 0 and 1 is calculated by the following equation 1, A method for selecting the oxidation number of a copper-based composite catalyst, wherein the ratio (%) of the above oxidation number 2 to copper is calculated by the following equation 2: [Formula 1] [Formula 2] In the above equations 1 and 2, Cu(0), Cu(I) and Cu(II) represent copper with oxidation number 0, copper with oxidation number 1 and copper with oxidation number 2, respectively. and satisfy, A1 is the sum of the total area of the Cu(0) main peak calculated through the XPS spectrum and the total area of the main peak for Cu(I), A2 is the total area of the Cu(II) main peak calculated through the XPS spectrum, B is the total area of satellite peaks for Cu(II) calculated through XPS spectra, As / Bs is Cu 2p of Cu(II) 3 / 2 It refers to the area ratio of the main peak / satellite peak.

8. In claim 6, The step of obtaining the XPS spectrum for the surface of the above copper-based composite catalyst is A step of deriving an XPS spectrum of the copper-based composite catalyst by X-ray photoelectron spectroscopy (XPS) under conditions of a vacuum atmosphere, a measurement range of 925 eV to 970 eV, and a pass energy of 50 eV; and A method for selecting the oxidation number of a copper-based composite catalyst, comprising a step of correcting the peak of the XPS spectrum.

9. In claim 8, The step of correcting the peak of the above XPS spectrum is A method for selecting the oxidation number of a copper-based composite catalyst, wherein the binding energy of the CC binding energy for graphite in the C 1s spectrum is fixed to a certain energy level as a reference, and the binding energy for the main peak for copper is corrected based on the energy level.

10. In claim 6, The step of calculating the total content (at%) of copper and the ratio (%) of copper with oxidation numbers 0 and 1 and copper with oxidation number 2 using the area of the above XPS spectrum is as follows. A step of deriving the total content of copper on the surface of the copper-based composite catalyst from the XPS spectrum; A step of deriving a first area value as the total area of the main peak for copper with oxidation number 0 and the main peak for copper with oxidation number 1 on the surface of the copper-based composite catalyst from the XPS spectrum; A step of deriving a second area value as the total area of the main peak for copper with oxidation number 2 on the surface of the copper-based composite catalyst from the XPS spectrum; A step of deriving a third area value as the total area of the satellite peak for copper on the surface of the copper-based composite catalyst from the XPS spectrum; and A method for selecting oxidation numbers of a copper-based composite catalyst, comprising the step of deriving the content (at%) of copper of oxidation numbers 0 and 1 and the content (at%) of copper of oxidation number 2, respectively, through the following equations 4 and 5: [Formula 4] [Formula 5] In the above equations 4 and 5, at%(Cu(0)+Cu(I)) is the total content of copper with oxidation number 0 and copper with oxidation number 1 in the copper-based composite catalyst, at% Cu(II) is the total content of copper in oxidation state 2 in the copper-based composite catalyst, % (Cu(0) + Cu(I)) is the ratio (%) of copper with oxidation numbers 0 and 1 calculated by the above equation 1, % Cu(II) refers to the ratio (%) of copper with oxidation number 2 calculated by the above equation 2.

11. In claim 10, The step of deriving the above first area value is A step of finding both the main peak for copper with oxidation number 0 and the main peak for copper with oxidation number 1 from the above XPS spectrum; and A step of calculating the area values of the main peak for copper with oxidation number 0 and the main peak for copper with oxidation number 1, respectively, and then adding all the calculated area values. A method for selecting the oxidation number of a copper-based composite catalyst comprising:

12. In claim 10, The step of deriving the above second area value is A step of finding all main peaks for copper with oxidation number 2 from the above XPS spectrum; and A step of calculating the area values of the main peaks for copper of the oxidation number 2, and then adding all the calculated area values. A method for selecting the oxidation number of a copper-based composite catalyst comprising:

13. In claim 10, The step of deriving the third area value is A step of finding all satellite peaks for copper from the above XPS spectrum; and A method for selecting the oxidation number of a copper-based composite catalyst, comprising the step of calculating the area values of satellite peaks for the copper, and then adding all of the calculated area values.

14. In claim 7, A method for selecting the oxidation number of a copper-based composite catalyst, wherein the As / Bs is 1.5 to 2.

1.

15. In claim 6, A method for selecting oxidation numbers of a copper-based composite catalyst, wherein the satellite peak for the above copper is a satellite peak for copper with an oxidation number of 2.

16. In claim 6, A method for selecting an oxidation number of a copper-based composite catalyst, wherein the copper-based composite catalyst comprises at least one of a copper oxide and a copper structure.

17. In claim 16 A method for selecting oxidation numbers of a copper-based composite catalyst, wherein the copper-based composite catalyst further comprises a carrier.

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