Aldehyde hydrogenation catalyst and its manufacturing method

Abstract

This invention relates to nickel diatomaceous earth catalysts and their manufacturing methods. The nickel diatomaceous earth catalyst is characterized as a catalyst for hydrogenating aldehydes. The catalyst comprises Ni, Zr, and diatomaceous earth. The Ni content, converted to NiO, is in the range of 40% to 90% by mass; the Zr content, converted to ZrO2, is in the range of 0.5% to 10% by mass; and the silica content, converted to SiO2, is in the range of 10% to 40% by mass. In the temperature-induced NH3 release determination, the NH3 release amount in the temperature range of 250℃ to 600℃ is greater than 1.00 mmol / g.

Description

[0001] This application is a divisional application of patent application No. 202380068811.2, filed on September 29, 2023, entitled "Aldehyde Hydrogenation Catalyst and Manufacturing Method Thereof". Technical Field

[0002] This invention relates to a catalyst for hydrogenating aldehydes. Background Technology

[0003] Catalysts for hydrogenating aldehydes to produce alcohols have been known since ancient times. For example, Patent Document 1 discloses a reduced nickel catalyst, wherein, relative to the nickel in a nickel diatomaceous earth catalyst, the reduced nickel catalyst contains 3% to 15% of one or more metals selected from magnesium, calcium, barium, strontium, and zirconium as a metal component. This document 1 discloses a method for hydrogenating saturated or unsaturated aldehydes to produce the corresponding alcohols using this reduced nickel catalyst. Furthermore, this document 1 describes that the side reactions of generating ethers and acetals are a significant problem in the hydrogenation of aldehydes using a nickel catalyst. Further noting that these side reactions are promoted by acids present in the catalyst, it is described that by including an alkaline metal salt in the catalyst, the side reactions are significantly suppressed. Additionally, Patent Document 2 describes that by highly dispersing silica with an alkali metal component immobilized on its surface in the catalyst, the side reactions are suppressed, and the selectivity for alcohols is increased.

[0004] Methods that do not use alkali metal components are also known, such as those described in Patent Document 3, which improve the selectivity of alcohols by using a catalyst in which the active component of the catalyst is loaded from the surface to the center in a gentle concentration gradient.

[0005] Therefore, in methods for producing alcohols by hydrogenating aldehydes, it is known to improve the selectivity of alcohols by changing the acidity of the catalyst or the loading state of the active metal. Existing technical documents Patent documents Patent Document 1: Japanese Patent Publication No. 44-17127 Patent Document 2: Japanese Patent Application Publication No. 2020-163334 Patent Document 3: Japanese Patent Application Publication No. 2005-279587 Summary of the Invention The technical problem that the invention aims to solve

[0006] The present invention solves the following problem: In the hydrogenation catalyst for producing alcohol by hydrogenation of aldehyde, the yield of alcohol is low when using existing catalysts due to significant side reactions such as the generation of ethers and acetals. Technical means to solve technical problems

[0007] The inventors have studied hydrogenation catalysts for producing alcohols by hydrogenating aldehydes and discovered that, in nickel-diatomaceous earth catalysts containing Ni, Zr, and diatomaceous earth, the formation of ethers and the like can be suppressed by using a nickel-diatomaceous earth catalyst containing a large amount of a solid acid with high acid strength, thereby increasing the yield of alcohols. The present invention uses a catalyst based on this discovery as a solution to address the aforementioned problems.

[0008] This invention relates to nickel diatomaceous earth catalysts (hereinafter also referred to as "the catalysts of this invention") and their manufacturing methods. The nickel diatomaceous earth catalyst is characterized as a catalyst for the hydrogenation of aldehydes, wherein the Ni content (converted to NiO) is in the range of 40% to 90% by mass, the Zr content (converted to ZrO2) is in the range of 0.5% to 10% by mass, the silica content (converted to SiO2) is in the range of 10% to 40% by mass, and in the temperature-induced NH3 release determination, the NH3 release amount in the temperature range of 250℃ to 600℃ is above 1.00 mmol / g, and the Ni crystallite diameter is in the range of 2 nm to 8 nm. Beneficial effects

[0009] If the catalyst of the present invention is used, in the method of producing alcohol by hydrogenating aldehyde, the formation of ethers and the like generated by side reactions can be suppressed, and the yield of alcohol can be increased. Attached Figure Description

[0010] [ Figure 1 NH3-TPD determination curves of Example 1, Comparative Example 1, and Comparative Example 2. [ Figure 2 XPS curve of Example 1. Detailed Implementation

[0011] The catalyst and its manufacturing method of the present invention will now be described in detail. Furthermore, in the present invention, when a numerical range is expressed as "~", it is considered that the numerical range includes both an upper and a lower limit. [The catalyst of the present invention] The catalyst of this invention is a nickel-diatomaceous earth catalyst, characterized in that the nickel-diatomaceous earth catalyst is a catalyst for hydrogenating aldehydes, the catalyst comprises Ni, Zr and diatomaceous earth, the Ni content (converted to NiO) is in the range of 40% to 90% by mass, the Zr content (converted to ZrO2) is in the range of 0.5% to 10% by mass, the silica content (converted to SiO2) is in the range of 10% to 40% by mass, and in the temperature rise determination of NH3, the amount of NH3 removed in the temperature range of 250℃ to 600℃ is 1.00 mmol / g or more.

[0012] As described in Patent Document 1, in catalysts used to hydrogenate aldehydes to produce alcohols, the acid contained in the catalyst promotes side reactions (reactions that produce compounds other than alcohols), and it is known that the acid can be reduced by adding alkali metals, etc. In contrast, the nickel-diatomite catalyst of the present invention, containing Ni, Zr and diatomite, is a catalyst containing a large amount of solid acid with high acid strength.

[0013] The strength and quantity of solid acids can be determined by measuring the NH3 removal upon heating. This measurement utilizes the phenomenon that NH3 is adsorbed onto a solid acid, and heating causes the adsorbed NH3 to be released. NH3 adsorbed onto strong solid acids is so strongly adhered that it only releases at high temperatures. Therefore, by measuring the amount of NH3 removed at the corresponding heating temperature, the quantity of solid acid corresponding to the acid strength can be determined.

[0014] In the NH3 desorption assay, the catalyst of the present invention desorbed more than 1.00 mmol / g in the temperature range of 250°C to 600°C (referred to as the high-temperature region). As shown in Table 2 below, the catalyst of Example 1 of the present invention desorbed 0.39 mmol / g in the temperature range of 100°C to less than 250°C (referred to as the low-temperature region), but the NH3 desorption amount increased significantly in the high-temperature region of 250°C to 600°C, reaching 1.84 mmol / g in the entire high-temperature region. This indicates that the catalyst of the present invention desorbs a large amount of NH3 in the high-temperature region and contains a large amount of solid acid with high solid acid strength (hereinafter also referred to as "strong solid acid").

[0015] Temperature changes in NH3 removal amount are shown in Figure 1 The NH3-TPD measurement curve. The catalyst of Example 1 of the present invention exhibits approximately 0.3 × 10⁻⁶ ppm in the low-temperature region of 100°C to less than 250°C. -3 The concentration of NH3 is below mmol / g, but the amount of NH3 released increases sharply in the high-temperature region of 250℃ to 600℃, reaching approximately 0.3 × 10⁻⁶ mmol / g at the measurement temperature. -3 mmol / g ~ approximately 0.7 × 10⁻⁶ -3 The NH3 removal rate is mmol / g, with a particularly high amount of NH3 removed in the high-temperature region. Furthermore, the overall NH3 removal rate for each temperature region within both the low-temperature and high-temperature regions is the cumulative value of NH3 removal at the measurement temperatures within each region.

[0016] The catalyst of the present invention preferably exhibits an overall NH3 removal amount of 1.10 mmol / g or more in the high-temperature region, more preferably in the range of 1.10 mmol / g or more to 3.00 mmol / g or less, and particularly preferably in the range of 1.10 mmol / g or more to 2.00 mmol / g or less. Furthermore, the catalyst of the present invention can exhibit an NH3 removal amount of 0.20 mmol / g or more in the low-temperature region, in the range of 0.20 mmol / g or more to 1.00 mmol / g or less, or in the range of 0.20 mmol / g to 0.40 mmol / g. Even with a high NH3 removal amount in the low-temperature region, the catalyst of the present invention achieves a high alcohol yield.

[0017] The catalyst of the present invention comprises Ni. In the catalyst, Ni exists in the form of metallic Ni, Ni oxide, or a portion thereof incorporated into diatomaceous earth. In the reaction of hydrogenating aldehydes, metallic Ni becomes the active metal. However, metallic Ni is readily oxidized in the atmosphere. Therefore, oxide catalysts are known that are pre-incorporated in the catalyst in the form of Ni oxide and pre-treated to reduce it to metallic Ni before the reaction, and reduction-stabilized catalysts are known that have an oxide coating pre-formed on the surface of metallic Ni and pre-treated to remove the oxide coating before the reaction. The catalyst of the present invention can be any of these. From the viewpoint of simplicity of pretreatment, reduction-stabilized catalysts are preferred. Furthermore, if Ni is incorporated into diatomaceous earth by bonding with silica (SiO2) contained in the diatomaceous earth, a strong solid acid is generated; therefore, it is preferred that at least a portion of Ni is bonded to the silica of the diatomaceous earth.

[0018] The Ni content in the catalyst of this invention, converted to NiO, ranges from 40% to 90% by mass relative to the total catalyst volume. While a higher Ni content results in higher activity in the hydrogenation of aldehydes, the catalyst price also increases. Therefore, considering economic efficiency, the Ni content in the catalyst is preferably in the range of 50% to 85% by mass, more preferably in the range of 60% to 80% by mass.

[0019] The catalyst of the present invention comprises Zr. In the catalyst, Zr is considered to exist in an oxide state, a state incorporated into diatomaceous earth, or both. If Zr is incorporated into diatomaceous earth, it forms bonds with the silica contained in the diatomaceous earth, and the electronic state of Zr changes. This change in electronic state can be confirmed by XPS measurements, showing that the energy level shifts to a position different from that of Zr in its oxide state. Furthermore, it is believed that the bonding between silica and Zr generates a strong solid acid, affecting the amount of NH3 removed. Therefore, the Zr contained in the catalyst of the present invention is preferably in a state in which some or all of it is incorporated into the diatomaceous earth.

[0020] like Figure 2As shown in the XPS curves, in the catalyst of Example 1 of the present invention, the bond energy of Zr contained in the catalyst (derived from the peak position of the 3d orbital) is 1 eV higher than the bond energy of ZrO2, indicating that at least a portion of the Zr contained in the catalyst of Example 1 is bonded to the silica of diatomaceous earth. Preferably, the bond energy of Zr in the catalyst of the present invention is 0.4 eV or more higher than the bond energy of ZrO2, more preferably 0.5 eV or more higher.

[0021] The Zr content of the catalyst of the present invention, converted to ZrO2, is in the range of 0.5% to 10% by mass relative to the total amount of catalyst. If the Zr content is within this range, a strong solid acid is easily formed. The Zr content is preferably in the range of 1% to 8% by mass, and more preferably in the range of 1% to 6% by mass.

[0022] The catalyst of the present invention comprises diatomaceous earth. Diatomaceous earth is a support for Ni and Zr. Diatomaceous earth is mainly composed of silica, and in the catalyst of the present invention, as described above, a portion of Ni and Zr is preferably bonded to the silica of the diatomaceous earth. The diatomaceous earth content in the catalyst of the present invention is preferably in the range of 10% to 40% by mass, more preferably in the range of 10% to 30% by mass, and particularly preferably in the range of 15% to 25% by mass.

[0023] Since the main component of diatomaceous earth is silicon dioxide, the content of diatomaceous earth in the catalyst of the present invention can be regarded as the silicon dioxide content. In the catalyst of the present invention, the silicon dioxide content is preferably in the range of 10% to 40% by mass, more preferably in the range of 10% to 30% by mass, and particularly preferably in the range of 15% to 25% by mass. In addition, besides diatomaceous earth, the catalyst of the present invention may also contain silicon dioxide particles as a forming agent and a pore-forming agent.

[0024] The silica content of the catalyst of the present invention is the total amount including silica from the forming agent and pore-forming agent. However, since this silica content is mainly composed of silica from diatomaceous earth, when forming agents and pore-forming agents are included, the amount of silica other than diatomaceous earth is limited according to the general proportions of these forming agents and pore-forming agents. Based on these proportions, the amount of silica derived from forming agents, pore-forming agents, etc., can be considered, for example, to be 5% by mass or less. In this case, in the 10% to 40% by mass silica content of the catalyst of the present invention, the amount of silica derived from diatomaceous earth is 5% to 35% by mass.

[0025] The catalyst of the present invention preferably has a Ni crystallite diameter in the range of 2 nm to 8 nm, more preferably in the range of 3 nm to 7 nm, and particularly preferably in the range of 4 nm to 6 nm. The Ni content in the catalyst of the present invention can be determined based on the diffraction peaks obtained by X-ray diffraction. In the present invention, the Ni crystallite diameter refers to the crystallite diameter of metallic Ni when the catalyst is a reduction stabilization catalyst, and to the crystallite diameter of NiO when the catalyst is an oxide catalyst. If the Ni crystallite diameter is smaller, the hydrogenation activity of the catalyst of the present invention tends to be higher.

[0026] The catalyst of this invention preferably has a specific surface area of ​​80 m². 2 / g or more, preferably 90m 2 / g or more, especially preferred is 100m 2 / g or more. In the catalyst of the present invention, if the specific surface area is within the stated range, its hydrogenation activity tends to be high. Furthermore, the specific surface area of ​​the catalyst of the present invention can be 300 m². 2 Below / g, it can be 250m 2 Below / g, or 200m 2 / g or less.

[0027] The catalyst of the present invention is preferably a shaped body. In the method of producing alcohol by hydrogenation of aldehydes, the catalyst of the present invention can be used in powder form, but a shaped body is preferred because it is easier to separate and recover after the reaction. The shape of the shaped body can be any shape known in the art. For example, spherical, columnar, or similar shapes are preferred, with columnar or similar shapes being the most desirable. The columnar shape also includes cylindrical, trilobal, tetralobal, and other similar shapes. Specifically, the catalyst of the present invention is columnar, preferably with a diameter of 0.5 mm to 5 mm and a length of 1 mm to 10 mm.

[0028] The catalyst of this invention is particularly suitable for methods of hydrogenating aldehydes to produce alcohols. However, the catalyst of this invention is also suitable for reactions in which Ni is the active species. For example, it can also be used for the hydrogenation of unsaturated compounds such as ethylene, propylene, benzene, and toluene.

[0029] Regarding the catalyst of the present invention, the present invention includes a method for manufacturing it (hereinafter also referred to as "the manufacturing method of the present invention"). The manufacturing method of the present invention will now be described in detail.

[0030] [Manufacturing method of the present invention] The method for manufacturing the catalyst of the present invention includes the following steps (a) to (g). (a) Acidic aqueous solution preparation process, to obtain an acidic aqueous solution containing dissolved Ni and Zr; (b) The alkaline suspension preparation process yields an alkaline suspension containing at least one of NaOH and Na2CO3 dissolved in it and diatomaceous earth dispersed in it; (c) Neutralization step, in which the acidic aqueous solution is added to the alkaline suspension to obtain a mixture; (d) A maturation process in which the pH of the mixture is adjusted to below 6.5 and maintained for at least 30 minutes; (e) A re-aging process in which the pH of the mixture obtained in the aging process is adjusted to the range of 8.5 to 9.5 and maintained for more than 60 minutes to obtain a precursor slurry; (f) Separation process, separating the precursor from the precursor slurry; (g) Firing process, firing the precursor. Each process is described in detail.

[0031] [Preparation process of acidic aqueous solution] The manufacturing method of the present invention includes an acidic aqueous solution preparation step to obtain an acidic aqueous solution containing dissolved Ni and Zr. Importantly, in this step, Ni and Zr are dissolved and ionized. The ionized Ni and Zr then form bonds with diatomaceous earth in the neutralization, aging, and reaging steps described later, forming a strong solid acid.

[0032] In this process, Ni and Zr raw materials are dissolved in water to prepare an acidic aqueous solution. There are no restrictions on the type of Ni raw material, as long as it dissolves in the acidic aqueous solution. For example, Ni sulfate, Ni nitric acid, Ni acetate, metallic Ni, etc., can be used. Similarly, there are no restrictions on the type of Zr raw material, as long as it dissolves in the acidic aqueous solution. For example, Zr sulfate, Zr nitric acid, etc., can be used. If these raw materials are insoluble in water, an acid can be used to dissolve them. There are no restrictions on the type of acid; for example, common inorganic acids such as sulfuric acid, nitric acid, and hydrochloric acid can be used.

[0033] The Ni and Zr content in the acidic aqueous solution obtained in this process can be adjusted according to the composition of the final catalyst. For example, the Ni content can be adjusted to a range of 1% to 12% by mass, or 3% to 10% by mass, or 5% to 7% by mass. Similarly, the Zr content can be adjusted to a range of 0.01% to 2% by mass, or 0.05% to 1% by mass, or 0.1% to 0.5% by mass.

[0034] Furthermore, the pH of the acidic aqueous solution obtained in this process is preferably 4 or lower, more preferably 3 or lower, and particularly preferably 2.5 or lower. Moreover, the lower limit of the pH is not limited and can be 1 or higher. If the pH is within the stated range, Ni and Zr are stably present in the acidic aqueous solution.

[0035] [Preparation process of alkaline suspension] The manufacturing method of the present invention includes an alkaline suspension preparation step of obtaining an alkaline suspension containing at least one of NaOH and Na2CO3 and in which diatomaceous earth is dispersed. In this step, it is important that the diatomaceous earth is dispersed as a solid in the solution, while a portion of it (mainly the surface) dissolves. The main component of diatomaceous earth is silicon dioxide, which dissolves in alkaline aqueous solutions. However, if all the diatomaceous earth dissolves, its pores will also disappear; therefore, this step prepares a suspension in which the diatomaceous earth exists in solid form. As a portion of the diatomaceous earth gradually dissolves in this suspension, bonds between Ni and Zr in the acidic aqueous solution mixed in the subsequent neutralization step and the diatomaceous earth become easier to form.

[0036] The alkaline suspension can be prepared by adding diatomaceous earth after dissolving at least one of NaOH and Na2CO3 in water, or by adding at least one of NaOH and Na2CO3 after dispersing diatomaceous earth in water. The amount of NaOH and Na2CO3 added is not limited, as long as it is added in the necessary amount to bring the pH to below 6.5 in the subsequent neutralization process.

[0037] The content of diatomaceous earth in the alkaline suspension obtained in this process can be adjusted according to the composition of the final catalyst. For example, the content of diatomaceous earth can be adjusted to a range of 1% to 20% by mass, 2% to 10% by mass, or 3% to 6% by mass. However, if the content of diatomaceous earth is too low, it will completely dissolve and cease to be a suspension. Therefore, it is recommended to adjust the content to a level where the diatomaceous earth can exist in a solid state.

[0038] The pH of the alkaline suspension obtained in this process is preferably in the range of 9 to 12.5, and more preferably in the range of 10 to 12. If left at a high pH for an extended period, the diatomaceous earth will dissolve; therefore, it is preferable to proceed to the next process before the diatomaceous earth has completely dissolved.

[0039] [Neutralization process] The manufacturing method of the present invention includes a neutralization step of adding the acidic aqueous solution to the alkaline suspension to obtain a mixture with a pH of 6.5 or lower. This step involves a neutralization reaction that causes Ni and Zr dissolved in the acidic solution to precipitate as precipitates and form bonds with Zr on the surface of the diatomaceous earth. Therefore, it is preferable to add the acidic aqueous solution to the alkaline suspension while maintaining a partially dissolved state of the diatomaceous earth.

[0040] The temperatures of the mixed acidic aqueous solution and the alkaline suspension are preferably in the range of 65°C to 95°C, and more preferably in the range of 75°C to 85°C. If the temperatures of the acidic aqueous solution and the alkaline suspension are within this range, the bonding reaction between Zr and diatomaceous earth will be promoted.

[0041] For the mixed acidic aqueous solution, it is preferable to add the total amount over a period of 15 to 120 minutes, more preferably over a period of 30 to 90 minutes. Adding the total amount of the acidic aqueous solution within such a time frame facilitates the formation of bonds between Zr and diatomaceous earth.

[0042] If the pH of the mixture does not fall below 6.5 after adding the total amount of the acidic aqueous solution, it is recommended to add more acidic aqueous solution as needed to adjust the pH to the stated range. The acidic aqueous solution available here may be an aqueous solution containing sulfuric acid, nitric acid, hydrochloric acid, acetic acid, or a mixture thereof.

[0043] [Curing process] The manufacturing method of the present invention includes a step of maintaining the mixture obtained in the neutralization step for 30 minutes or more. In this step, it is important to promote the reaction that forms bonds with Zr on the surface of the diatomaceous earth. The maintaining time is preferably 45 minutes or more, more preferably 60 minutes or more. There is no upper limit to the maintaining time, but from a production point of view, it can be 600 minutes or less, 300 minutes or less, or 150 minutes or less. In this case, it is preferable to maintain the mixture while it is being stirred.

[0044] The temperature of the mixture in the curing process is preferably in the range of 65°C to 95°C, and more preferably in the range of 75°C to 85°C. If the temperature of the mixture is within this range, the reaction that establishes the bond between Zr and diatomaceous earth will be promoted.

[0045] [Re-curing process] The manufacturing method of the present invention includes a step of adjusting the pH of the mixture obtained in the aging process to a range of 8.5 to 9.5 and maintaining it for at least 60 minutes to obtain a precursor slurry. Importantly, in this step, the formation of bonds between Ni and diatomaceous earth is achieved by aging the mixture at a pH different from that of the aging process.

[0046] In this process, an alkaline compound is added to the mixture obtained in the aging process to adjust the pH to the range of 8.5 to 9.5. The added alkaline compound can be any known compound. For example, NaOH, Na₂CO₃, ammonia, or aqueous solutions of these compounds can be used. By adjusting the pH to this range and aging for more than 1 hour, the bond between Ni and diatomaceous earth is further formed. The temperature of the mixture during further aging is preferably in the range of 65°C to 95°C, more preferably in the range of 75°C to 85°C. If the temperature of the mixture is within this range, the reaction that forms the bond between Ni and diatomaceous earth is promoted.

[0047] [Separation Process] The manufacturing method of the present invention includes a step of separating the precursor from the precursor slurry obtained in the above-described steps. In this step, existing and known methods can be used to separate the precursor from the precursor slurry. For example, methods such as using a dryer to remove water, separating water by filtration, or separating water by centrifugation can be used.

[0048] When the precursor slurry contains impurities generated by neutralization reactions, these impurities can be removed by suspension washing or flow-through washing. Suspension washing involves suspending the separated precursor in water, stirring, and then separating the precursor again. Flow-through washing involves circulating a washing liquid such as water through the catalyst precursor. In particular, when the precursor contains a large amount of sulfur, washing is preferred to remove the sulfur as it may reduce catalyst activity. Furthermore, in the case of nitrate ions, these impurities will contribute to the generation of NO in the subsequent calcination process. X Therefore, it is preferable to remove it by washing. For example, it is preferable to wash in such a way that the conductivity of the filtrate after washing is less than 5 mS / cm.

[0049] The separated precursor can be shaped into various forms as needed. For example, it can be shaped into spheres, cylinders, or similar shapes, preferably cylinders or similar shapes. The cylinder shape also includes cylindrical, trilobal, tetralobal, and other similar shapes. Specifically, it is preferred to shape it into a cylinder with a diameter of 0.5 mm to 5 mm and a length of 1 mm to 10 mm. Existing known methods such as stamping and extrusion molding can be used to shape it into such a form.

[0050] [Firing process] The manufacturing method of the present invention includes a step of calcining the precursor separated in the above-described steps. Importantly, in this step, the precipitates contained in the precursor are decomposed to generate nickel oxide. The calcined precursor can be used as an oxide catalyst in a method for hydrogenating aldehydes to produce alcohols. When using an oxide catalyst, a pretreatment is required, wherein the nickel oxide is reduced to its metallic state using a reducing agent such as hydrogen.

[0051] In this process, existing and known equipment can be used to calcine the precursor. For example, a muffle furnace, rotary kiln, or gas furnace can be used to calcine the catalyst precursor. Furthermore, the calcination temperature depends on the temperature at which the precursor decomposes, and calcination is preferably carried out in the temperature range of 300°C to 500°C. In addition, the calcination time also depends on the amount of precursor and can range from 1 hour to 24 hours. The calcination atmosphere is preferably atmospheric, but calcination can also be carried out under circulating atmospheric conditions.

[0052] In this process, the oxide catalyst obtained after calcining the precursor can be reduced using hydrogen or other means, as needed. For example, by filling the reaction vessel with the oxide catalyst and maintaining a reaction temperature of 380°C to 450°C for 1 to 48 hours under hydrogen flow, nickel oxide can be reduced to metallic nickel. Furthermore, if the metallic nickel generated from the reduction of nickel oxide is directly exposed to the atmosphere, there is a risk of heat generation and catalyst combustion due to oxidation. Therefore, after reducing nickel oxide, it is recommended to gradually supply oxygen to form a nickel oxide coating on the surface of the metallic nickel. Alternatively, carbon dioxide or other substances can be adsorbed onto the surface of the metallic nickel. The catalyst obtained through this reduction stabilization process can be used as a reduction stabilization catalyst in methods for producing alcohols by hydrogenating aldehydes. Compared to the oxide catalyst described above, the reduction stabilization catalyst requires significantly less pretreatment time and is therefore preferred.

[0053] Hereinafter, embodiments of the present invention are shown together with comparative examples. However, the present invention is not limited to these embodiments. In the embodiments and comparative examples, various measurements or evaluations were performed as follows.

[0054] [pH Measurement] The pH value was measured at a liquid temperature of 40°C using a pH meter (manufactured by Yamagata Toa DKK Co., Ltd., "MM43-X") and a pH electrode (manufactured by Yamagata Toa DKK Co., Ltd., "GST-5841C").

[0055] [Compositional Analysis] (Ni, Zr, and Si) The sample was dissolved in acid, and the filtrate was diluted with water to an appropriate concentration. The contents of Ni, Zr, and Si were then determined using an ICP emission spectrometer (manufactured by Agilent Technologies, Inc., 730 ICP-OES, inductively coupled plasma optical emission spectrometry). Furthermore, the contents of each component were calculated based on the total amount of catalyst, with Ni converted to NiO, Zr to ZrO2, and Si to SiO2.

[0056] [NH3-TPD determination] The amount of ammonia removed was determined by the ammonia removal method using the NH3-TPD method. Using a BELCAT-II (registered trademark) measuring unit manufactured by Microtrail Bell, 0.05 g of sample was placed in the measuring unit and pretreated at 250°C for 1 hour in a hydrogen atmosphere. Then, the temperature was set to 100°C, ammonia gas was introduced, and adsorption was performed for 1 hour. Next, after exhaust treatment at 100°C in a helium atmosphere, the temperature was increased from 100°C to 600°C at a flow rate of 30 ml / min, while simultaneously detecting the amount of ammonia removed with increasing temperature using a TCD detector, once per second. Finally, the calibration factor was calculated based on the TCD signal intensity under 100% helium flow and the TCD signal intensity of a 5.14 Vol% NH3 / He mixture. Using this calibration factor, the TCD signals from 100°C to 600°C were converted into NH3 concentrations (mmol), which were then divided by the sample weight to determine the ammonia removal per 1g of sample at each time point. A graph was constructed with the ammonia removal per 1g of sample on the ordinate and time on the abscissa. The time from 250°C to 600°C was integrated to determine the ammonia removal between 250°C and 600°C. Furthermore, the ammonia removal between 100°C and 250°C was determined using the same method. These calculations were performed using the analytical software provided with the device.

[0057] [Crystal Diameter Measurement] X-ray diffraction measurements were performed on the samples using an X-ray diffraction apparatus (Rigaku MultiFlex) manufactured by Rigaku Corporation. First, the sample to be measured was crushed, loaded into a sample plate, and X-ray diffraction (line source Cu-Kα rays) was performed under the following conditions: tube voltage 40 kV, tube current 20 mA, scanning range 10°–70°, divergence slit 1.0 mm, scattering slit 1.0 mm, receiving slit 0.3 mm, and scanning speed 4° / min. The diffraction peak with a apex near 2θ = 44° was detected by X-ray diffraction measurement, and the Ni crystallite diameter was calculated using Scherrer's formula with analytical software (JADE Version 5.0). Furthermore, the NiO crystallite diameter of the oxide catalyst was calculated based on the diffraction peak with a apex near 2θ = 62°.

[0058] [Specific Surface Area Measurement] Specific surface area was calculated using the nitrogen adsorption method (BET method). Specifically, using a specific surface area measuring device (Mountech, Macsorb 1220), approximately 0.1 g of sample was placed in the measuring unit and degassed at 250°C for 40 minutes in a nitrogen gas stream. The sample was then kept at liquid nitrogen temperature in a mixed gas stream of 30% by volume nitrogen and 70% by volume helium to allow nitrogen to be adsorbed onto the sample at equilibrium. Then, while the mixed gas was flowing, the sample temperature was gradually increased to room temperature, and the amount of nitrogen removed during this process was measured. This amount was then divided by the final sample weight to calculate the sample's specific surface area.

[0059] [XPS Measurement] XPS measurements were performed using a Thermo Fisher Scientific ESCALAB 220I-X apparatus under the following conditions. Furthermore, commercially available reagents (zirconia, 3N, manufactured by Kanto Chemical Co., Ltd.) were used as standard samples. Source: Monochromatic Al Kα line Accelerating voltage and current: 10KV, 19.0mA Energy: 20eV Dwell time: 50ms Energy step size: 0.1 eV

[0060] [Activity Evaluation: Hydrogenation of Aldehydes] <Preprocessing> After adding 4.0 g of sample to the glass tube, it was kept at 150 °C for 60 minutes under a hydrogen atmosphere. Then, the glass tube was replaced with nitrogen gas and cooled to room temperature. Finally, the sample was placed in an autoclave under a nitrogen atmosphere. <Hydrogenation Experiment> 100.3 g of n-butyraldehyde was injected into the autoclave. After injection, the mixture was stirred at 400 rpm while the temperature was increased to 100°C. After heating, hydrogen was injected until the pressure inside the autoclave reached 5 MPa, and the pressure was maintained at 5 MPa for 2 hours. After maintaining this pressure, the mixture was cooled to room temperature to obtain the reaction solution. <Analysis> The reaction solution was analyzed using a gas chromatograph (Shimadzu Corporation, GC-14B) to determine the mass content of n-butyraldehyde (NBD), n-butanol (NBA), dibutyl ether (Et), 2-ethyl-1,3-hexanediol (Diol), and butyraldehyde dibutyl acetal (Ac). The mass content of each component was then converted to molar content, and the conversion rate and selectivity were calculated using the following formulas. [Conversion Rate] Conversion rate (%) = (Molar NBD content after reaction - Molar NBD content before reaction) / Molar NBD content before reaction × 100 [NBA Draft Pick Rate] NBA pick rate (%) = Post-reaction NBA molar content / (Post-reaction NBD molar content - Pre-reaction NBD molar content) × 100 [Et selectivity] Et selectivity (%) = Et molar content after reaction × 2 / (NBD molar content after reaction - NBD molar content before reaction) × 100 [Diol Selection Rate] Diol selectivity (%) = Diol molar content after reaction × 2 / (NBD molar content after reaction - NBD molar content before reaction) × 100 [Ac selection rate] Ac selectivity (%) = Post-reaction molar content of Ac × 3 / (Post-reaction molar content of NBD - Pre-reaction molar content of NBD) × 100

[0061] [Example 1] Preparation process of acidic aqueous solution 1418.0 g of nickel sulfate hydrate [Ni(SO4)2·6H2O] (manufactured by Fujifilm and Wako Pure Chemical Industries Co., Ltd.) was dissolved in 5.4 L of tap water, and then 94.0 g of zirconium sulfate solution (manufactured by Daiichi Rare Element Chemical Industry Co., Ltd.) was added. The temperature was adjusted to 80 °C to prepare an acidic aqueous solution. The pH of the acidic aqueous solution was 2.1.

[0062] Alkaline suspension preparation process 3.1L of tap water was added to a 15L stirred tank, and 333.0g of sodium carbonate (Na2CO3, manufactured by Kanto Chemical Co., Ltd.) was dissolved in it, adjusting the temperature to 80°C. Then, 76.3g of diatomaceous earth [Celite505] (manufactured by Imerys Co., Ltd.) and 53.5g of diatomaceous earth [FilterCel] (manufactured by Imerys Co., Ltd.) were added. The mixture was then stirred for 60 minutes to disperse the diatomaceous earth, preparing an alkaline suspension. The pH of the alkaline suspension was 11.3. Using two types of diatomaceous earth resulted in good formability and good bonding with Ni and Zr.

[0063] neutralization process The acidic aqueous solution was added to the alkaline suspension using a tubular pump over 80 minutes to obtain a mixture. The pH of the mixture was 6.3.

[0064] ripening process While maintaining the mixture at 80°C, continue stirring for 1 hour.

[0065] Re-curing process 645.0 g of sodium carbonate (manufactured by Kanto Chemical Co., Ltd.) was dissolved in 3.0 L of tap water and the temperature was adjusted to 80 °C to prepare an alkaline aqueous solution for pH adjustment. This solution was then added to the above mixture after the aging process using a tubular pump within 10 minutes, adjusting the pH to 9.5. After the addition was completed, the mixture was stirred for another 120 minutes while maintaining the temperature at 80 °C to obtain the precursor slurry.

[0066] Precursor separation process The precursor slurry was filtered under reduced pressure using a suction filter to obtain a cake-like precursor. This precursor was then completely immersed in 6 L of warm water adjusted to 40°C, filtered, and subjected to suspension washing. This process was repeated until the conductivity of the filtrate reached 1.5 mS / cm. The cake-like precursor was dried in a box dryer at 120°C for 12 hours. The dried cake-like precursor was then pulverized using a hammer mill to obtain a powdered precursor.

[0067] Catalyst precursor calcination process The precursor was formed into a cylindrical shape with a diameter of 3.2 mm and a height of 3.2 mm using a sprue forming machine. The precursor was then calcined in a muffle furnace at 370°C for 6 hours to obtain an oxide catalyst. Further, the oxide catalyst was reduced at 430°C for 10 hours under a hydrogen atmosphere and then stabilized at 80°C to obtain the final catalyst. Manufacturing conditions are shown in Table 1. Furthermore, samples were used for the above-mentioned measurements and evaluations. The results are shown in Table 2.

[0068] The NH3-TPD determination curve of this catalyst is shown together with that of the catalysts in Comparative Example 1 and Comparative Example 2. Figure 1 . Figure 1 The amount of NH3 removed is shown in relation to the heating temperature. Furthermore, the XPS curves of Zr for this catalyst are compared with those of ZrO2, as shown below. Figure 2 .

[0069] [Example 2] Except for the use of 500.0 g of sodium carbonate (manufactured by Kanto Chemical Co., Ltd.) in the re-aging process and the setting of the pH of the mixture to 8.8, the catalyst was obtained using the same method as in Example 1. The obtained catalyst was subjected to the above-described determinations or evaluations.

[0070] [Example 3] Except for the addition of 64.1 g of diatomaceous earth [Celite 505] (manufactured by Imerys) and 45.0 g of diatomaceous earth [FilterCel] (manufactured by Imerys) in the alkaline suspension preparation step, the catalyst was obtained using the same method as in Example 1. The obtained catalyst was subjected to the above-described determinations or evaluations.

[0071] [Example 4] The catalyst was obtained using the same method as in Example 1, except that 43.1 g of zirconium sulfate solution (manufactured by Daiichi Rare Element Chemical Industry Co., Ltd.) was added in the acidic aqueous solution preparation step, and 64.1 g of diatomaceous earth [Celite 505] (manufactured by Imerys Co., Ltd.) and 45.0 g of diatomaceous earth [FilterCel] (manufactured by Imerys Co., Ltd.) were added in the alkaline suspension preparation step. The obtained catalyst was subjected to the above-described determinations or evaluations.

[0072] [Comparative Example 1] Except for the use of 379.5 g of sodium carbonate (manufactured by Kanto Chemical Co., Ltd.) in the re-aging process and the setting of the pH of the mixture to 7.5, the catalyst was obtained using the same method as in Example 1. The obtained catalyst was subjected to the above-described measurements or evaluations.

[0073] [Comparative Example 2] The catalyst was obtained using the same method as in Example 1, except that the holding time was set to 0 during the re-aging process. The obtained catalyst was then subjected to the above-described measurements or evaluations.

[0074] [Table 1]

[0075] [Table 2]

Claims

1. A nickel-diatomite catalyst, characterized in that, The nickel diatomite catalyst is a catalyst for the hydrogenation of aldehydes. The catalyst contains Ni, Zr, and diatomaceous earth. The Ni content, converted to NiO, is in the range of 40% to 90% by mass. The Zr content, converted to ZrO2, is in the range of 0.5% to 10% by mass. The silica content, converted to SiO2, ranges from 10% to 40% by mass. In the temperature-induced NH3 release assay, the amount of NH3 released in the temperature range of 250℃ to 600℃ was above 1.00 mmol / g. Ni crystallites have diameters ranging from 2 nm to 8 nm.

2. The nickel diatomaceous earth catalyst as described in claim 1, characterized in that, Specific surface area is 80m² 2 / g or more.

3. The nickel diatomaceous earth catalyst as described in claim 1 or 2, characterized in that, The bond energy of Zr is more than 0.4 eV higher than that of ZrO2.

4. A method for manufacturing a nickel diatomaceous earth catalyst, characterized in that, The manufacturing method is a method for manufacturing a catalyst for hydrogenating aldehydes, and the manufacturing method includes: The acidic aqueous solution preparation process yields an acidic aqueous solution containing dissolved Ni and Zr. The alkaline suspension preparation process yields an alkaline suspension containing at least one of NaOH and Na2CO3 dissolved in it and diatomaceous earth dispersed in it. In the neutralization process, the acidic aqueous solution is added to the alkaline suspension to obtain a mixture; The maturation process involves adjusting the pH of the mixture to below 6.5 and maintaining this pH for at least 30 minutes. The re-aging process involves adjusting the pH of the mixture obtained in the re-aging process to the range of 8.5 to 9.5 and maintaining it for more than 60 minutes to obtain the precursor slurry. A separation process is used to separate the precursor from the precursor slurry; The firing process involves firing the precursor.

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