Catalyst with reduced chroma function and process for the preparation of isooctanoic acid

Abstract

The application relates to the chemical process field and discloses a catalyst with a function of reducing chroma and a method for preparing isooctanoic acid. The catalyst and the method for synthesizing isooctanoic acid can reduce the chroma of isooctanoic acid products and downstream products prepared by using isooctanoic acid as raw materials after long-time storage, improve product quality, reduce the requirement of the raw material storage environment, thereby reducing the cost and improving the benefit.

Description

Technical Field

[0001] This invention relates to the field of chemical processes, specifically to a catalyst with color-reducing function and a method for preparing isooctanoic acid. Background Technology

[0002] Isooctanoic acid is an important fine chemical organic product. At room temperature (25°C), it is a colorless, transparent liquid with an aromatic odor similar to chrysanthemum and gardenia. It is slightly soluble in cold water and soluble in hexane, cyclohexane, benzene, acetonitrile, and alcohols. Isooctanoic acid is a high-value-added fine chemical that readily reacts with metals, primarily forming metal salts, including Mn, Co, Ca, and Na salts. As an important organic intermediate, isooctanoic acid's main downstream products are metal salt compounds. Different isooctanoates can be used in various industrial production fields. Due to its excellent application performance and green, pollution-free characteristics, it can replace some traditional chemical raw materials, promoting green upgrading of production processes and products. Furthermore, high-performance cold-resistant plasticizers synthesized from isooctanoic acid also have significant application value.

[0003] Currently, there are two main process routes for preparing isooctanoic acid. The most common method is the butyraldehyde condensation process: first, butyraldehyde is condensed to prepare 2-ethylhexenal; then, 2-ethylhexenal is selectively hydrogenated using platinum or nickel catalysts, or palladium or rare earth oxide catalysts, to produce isooctanoic acid, with isooctyl alcohol as a byproduct. Finally, isooctanoic acid is oxidized using potassium permanganate, Mn acetate, or Co acetate as catalysts. However, the color of isooctanoic acid products obtained by these methods, or downstream products prepared from isooctanoic acid, is significantly affected after long-term storage. CN115916736 uses inert gas stripping to remove molecular oxygen from the mixture, which to some extent suppresses the increase in color, but it cannot completely suppress the increase in color.

[0004] Therefore, there is an urgent need for a process to prepare high-purity isooctanoic acid in order to reduce the color of isooctanoic acid or its downstream products. Summary of the Invention

[0005] The purpose of this invention is to overcome the problems existing in the prior art and to provide a catalyst with color-reducing function and a method for preparing isooctanoic acid.

[0006] To achieve the above objectives, a first aspect of the present invention provides a catalyst with a color reduction function, the catalyst comprising a support and an active component supported on the support, wherein the active component preferably comprises cerium oxide and other metal oxides, wherein the other metal oxides preferably include at least one of copper oxide, iron oxide, chromium oxide and manganese oxide.

[0007] A second aspect of the present invention provides a method for preparing a catalyst, the method comprising: attaching a precursor of an active component to a support and then calcining it, wherein the active component preferably includes cerium oxide and other metal oxides, wherein the other metal oxides preferably include at least one selected from copper oxide, iron oxide, chromium oxide and manganese oxide.

[0008] A third aspect of the present invention provides a method for preparing isooctanoic acid, the method comprising:

[0009] (1) In the presence of a first catalyst and a solvent, isooctaldehyde reacts with oxygen to undergo a first reaction to obtain crude isooctanoic acid;

[0010] (2) In the presence of a second catalyst, the crude isooctanoic acid obtained in step (1) is brought into contact with hydrogen to carry out a second reaction to obtain the isooctanoic acid product.

[0011] The beneficial effects obtained by the present invention through the above technical solution include at least the following:

[0012] Using the catalyst and method for synthesizing isooctanoic acid provided by this invention can reduce the color of isooctanoic acid products and downstream products prepared from isooctanoic acid as raw materials after long-term storage, improve product quality, reduce the requirements for raw material storage environment, thereby reducing costs and increasing profits. Detailed Implementation

[0013] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0014] A first aspect of the present invention provides a catalyst having a color reduction function, the catalyst comprising a support and an active component supported on the support, wherein the active component preferably comprises cerium oxide and other metal oxides, wherein the other metal oxides preferably comprise at least one of copper oxide, iron oxide, chromium oxide and manganese oxide.

[0015] In this invention, the weight ratio of cerium oxide to the support is preferably (0.01-0.05):1, for example, it can be 0.01:1, 0.015:1, 0.02:1, 0.025:1, 0.03:1, 0.035:1, 0.04:1, 0.045:1, 0.05:1, and any range between any two values ​​and any value within the range, more preferably (0.01-0.025):1.

[0016] In this invention, the weight ratio of the other metal oxide to the carrier is preferably (0.0005-0.01):1, for example, it can be 0.0005:1, 0.001:1, 0.002:1, 0.003:1, 0.004:1, 0.005:1, 0.006:1, 0.007:1, 0.008:1, 0.009:1, 0.01:1, and any range between any two values ​​and any value within the range, more preferably (0.002-0.007):1.

[0017] In this invention, the weight ratio of copper oxide to carrier is preferably (0.001-0.005):1, for example, it can be 0.01:1, 0.015:1, 0.02:1, 0.025:1, 0.03:1, 0.035:1, 0.04:1, 0.045:1, 0.05:1, and any range between any two values ​​and any value within the range, more preferably (0.002-0.004):1.

[0018] In this invention, the weight ratio of the iron oxide to the carrier is preferably (0.001-0.007):1, for example, it can be 0.01:1, 0.015:1, 0.02:1, 0.025:1, 0.03:1, 0.035:1, 0.04:1, 0.045:1, 0.05:1, 0.055:1, 0.06:1, 0.065:1, 0.07:1, and any range between any two values ​​and any value within the range, more preferably (0.002-0.0035):1.

[0019] In this invention, the weight ratio of the chromium oxide to the carrier is preferably (0.0003-0.003):1, for example, it can be 0.0003:1, 0.0004:1, 0.0005:1, 0.0006:1, 0.0007:1, 0.0008:1, 0.0009:1, 0.001:1, 0.002:1, 0.003:1, and any range between any two values ​​and any value within the range, more preferably (0.0005-0.0009):1.

[0020] In this invention, the weight ratio of the manganese oxide to the carrier is preferably (0.0005-0.002):1, for example, it can be 0.0005:1, 0.0006:1, 0.0008:1, 0.001:1, 0.0012:1, 0.0014:1, 0.0016:1, 0.0018:1, 0.002:1, and more preferably (0.0006-0.0016):1.

[0021] In this invention, the other metal oxides are preferably copper oxides and manganese oxides in a weight ratio of 1:(0.1-0.5), for example, 1:0.1, 1:0.14, 1:0.18, 1:0.22, 1:0.26, 1:0.3, 1:0.34, 1:0.38, 1:0.42, 1:0.46, 1:0.5, and any value within any range of any two values, more preferably copper oxides and manganese oxides in a weight ratio of 1:(0.3-0.45).

[0022] In this invention, the other metal oxides are preferably iron oxides and chromium oxides in a weight ratio of 1:(0.1-0.5), for example, 1:0.1, 1:0.14, 1:0.18, 1:0.22, 1:0.26, 1:0.3, 1:0.34, 1:0.38, 1:0.42, 1:0.46, 1:0.5, and any value within any range of any two values, more preferably iron oxides and chromium oxides in a weight ratio of 1:(0.35-0.45).

[0023] In this invention, the carrier preferably includes activated carbon and silicon carbide. More preferably, the weight ratio of activated carbon to silicon carbide is (0.01-0.1):1, for example, it can be 0.01:1, 0.02:1, 0.03:1, 0.04:1, 0.05:1, 0.06:1, 0.07:1, 0.08:1, 0.09:1, 0.1:1, and any range of any two values ​​and any value within the range.

[0024] A second aspect of the present invention provides a method for preparing a catalyst, the method comprising: attaching a precursor of an active component to a support and then calcining it, wherein the active component preferably includes cerium oxide and other metal oxides, wherein the other metal oxides preferably include at least one selected from copper oxide, iron oxide, chromium oxide and manganese oxide.

[0025] In this invention, the weight ratio of cerium oxide to the support is (0.01-0.05):1, preferably (0.01-0.025):1.

[0026] In this invention, the weight ratio of the other metal oxides to the carrier is (0.0005-0.01):1, preferably (0.002-0.007):1.

[0027] In this invention, the weight ratio of copper oxide to carrier is (0.001-0.005):1, preferably (0.002-0.004):1.

[0028] In this invention, the weight ratio of the iron oxide to the carrier is (0.001-0.007):1, preferably (0.002-0.0035):1.

[0029] In this invention, the weight ratio of the chromium oxide to the carrier is (0.0003-0.003):1, preferably (0.0005-0.0009):1.

[0030] In this invention, the weight ratio of the manganese oxide to the carrier is (0.0005-0.002):1, preferably (0.0006-0.0016):1.

[0031] In this invention, the other metal oxides are copper oxide and manganese oxide in a weight ratio of 1:(0.1-0.5), preferably copper oxide and manganese oxide in a weight ratio of 1:(0.3-0.45).

[0032] In this invention, the other metal oxides are iron oxides and chromium oxides in a weight ratio of 1:(0.1-0.5), preferably iron oxides and chromium oxides in a weight ratio of 1:(0.35-0.45).

[0033] The weight ratios of the aforementioned cerium oxides, other metal oxides, iron oxides, chromium oxides, and manganese oxides to the carrier, the weight ratios of copper oxides and manganese oxides, and the weight ratios of iron oxides and chromium oxides are within the same range as those described in the first aspect, and will not be repeated here.

[0034] In this invention, the preferred method for attaching the precursor of the active component to the carrier is to mix the precursor of the active component, activated carbon, and water, and then spray the resulting mixture onto silicon carbide. Alternatively, silicon carbide can be immersed in the mixture of the precursor of the active component, activated carbon, and water. According to some preferred embodiments of the present invention, spraying is preferred.

[0035] In this invention, the thermal decomposition temperature of the precursor of the active component is preferably 100-350℃.

[0036] In this invention, the precursor of the active component is preferably a nitrate of a metal element in the active component.

[0037] In this invention, the calcination temperature can be adjusted according to the type of precursor of the active component, as long as the precursor of the active component can be decomposed. Therefore, the calcination temperature can be 350-1000℃, and preferably 390-500℃ in order to reduce energy consumption and improve safety.

[0038] According to some preferred embodiments of the present invention, the method for preparing the catalyst is as follows: by weight, 0.4-0.6 parts of copper nitrate, 4-6 parts of cerium ammonium nitrate, 0.1-0.2 parts of manganese nitrate, and 4-6 parts of activated carbon are mixed with 130-150 parts of water and sprayed onto 90-110 parts of silicon carbide ceramic at a temperature of 240-310°C, and then calcined at 390-405°C.

[0039] According to some preferred embodiments of the present invention, the method for preparing the catalyst is as follows: by weight, 0.5-0.9 parts of ferric nitrate, 4-6 parts of cerium ammonium nitrate, 0.1-0.3 parts of chromium nitrate, and 4-6 parts of activated carbon are mixed with 130-150 parts of water and sprayed onto 90-110 parts of silicon carbide ceramic at a temperature of 240-310°C, and then calcined at 395-420°C.

[0040] A third aspect of the present invention provides a method for preparing isooctanoic acid, the method comprising:

[0041] (1) In the presence of a first catalyst and a solvent, isooctaldehyde reacts with oxygen to undergo a first reaction to obtain crude isooctanoic acid;

[0042] (2) In the presence of a second catalyst, the crude isooctanoic acid obtained in step (1) is brought into contact with hydrogen to carry out a second reaction to obtain the isooctanoic acid product.

[0043] In this invention, in step (1), the first catalyst can be a carboxylate, preferably isooctanoate, and more preferably sodium isooctanoate.

[0044] In this invention, the weight ratio of the first catalyst to isooctaldehyde can be 1:(100-300).

[0045] In this invention, the solvent can be a C1-C10 carboxylic acid, preferably isooctanoic acid.

[0046] In this invention, the molar ratio of isooctaldehyde to oxygen can be 1:(0.5-1).

[0047] In this invention, the conditions for the first reaction include: a temperature of 50-70°C, a pressure of 1-10 MPa, and a time of 1-10 h.

[0048] In this invention, the second catalyst is the catalyst as described above and / or the catalyst prepared by the method described above.

[0049] In this invention, in step (2), the volume ratio of hydrogen gas to the solution containing crude isooctanoic acid can be 1:(0.5-2), for example, it can be 1:0.5, 1:0.7, 1:0.9, 1:1.1, 1:1.3, 1:1.5, 1:1.7, 1:1.9, 1:2, and any value within any range of any two values.

[0050] In this invention, the volume hourly space velocity of the hydrogen gas can be 0.5-5 h⁻¹. -1 For example, it can be 0.5h -1 0.8h -1 1.1h -1 1.4h -1 1.7h -1 2h -1 2.3h -1 2.6h -1 2.9h -1 3.2h -1 3.5h -1 3.8h -1 4.1h -1 4.4h -1 4.7h -1 5h -1 And the range formed between any two values ​​and any value within the range, preferably 1-4, more preferably 1.5-3.5h. -1 .

[0051] In this invention, the conditions for the second reaction include: a temperature of 45-70°C, for example, 45°C, 47°C, 49°C, 51°C, 53°C, 55°C, 57°C, 59°C, 61°C, 63°C, 65°C, 67°C, 69°C, or 71°C, preferably 45-55°C; a pressure of 0.09-0.2 MPa; and a time of 0.5-5 h.

[0052] According to the present invention, in order to obtain an isooctanoic acid product with a higher isooctanoic acid content, the method further includes performing at least one distillation after the first reaction. The distillation can be performed after the first reaction ends and before the second reaction begins, or it can be performed after the second reaction ends. The distillation can be performed using equipment conventionally used in the art, such as at least one of a rotary evaporator, a reflux distiller, or a distillation column. The choice can be flexible depending on the type of impurities and the purity requirements of the product. In some embodiments of the present invention, the distillation is performed in a glass vacuum distiller with a vacuum degree of -1.2 to -0.3 MPa, an initial temperature of 40-50°C, and gradual heating. When the temperature reaches 100-130°C, the distillate is collected.

[0053] According to the most preferred embodiment of the present invention, a method for obtaining isooctanoic acid products includes:

[0054] (1) An oxidation reaction of isooctaldehyde, isooctanoic acid and sodium isooctanoate with a ratio of (150-175):(600-700):1 was carried out using air as an oxidant. The reaction temperature was 60-65℃, the pressure was 2.8-3.5MPa, and the reaction time was 2-3 hours to obtain a crude isooctanoic acid solution. The crude isooctanoic acid solution was then distilled to obtain a fraction.

[0055] (2) Under the condition of the presence of a catalyst (the catalyst includes iron oxide, cerium oxide, chromium oxide, activated carbon, and silicon carbide ceramic balls in a weight ratio of (1.5-3):(15-22):1:(50-60):(900-1200), the volume ratio of hydrogen to distillate is 1:(0.9-1.2), the pressure is 0.09-0.11 MPa, the temperature is 48-52℃, and the volume hourly space velocity of hydrogen is 1.8-2.2 h⁻¹. -1 The reaction yields isooctanoic acid, with a color intensity of less than 2 and an oxidizing impurity equivalent of less than 10 × 10⁻⁶. -6 mol / g.

[0056] The present invention will be described in detail below through embodiments.

[0057] Effective volume of the oxidation reactor: 4.8L;

[0058] Activated carbon: specific surface area 1500m² 2 / g, pore size 350μm;

[0059] Silicon carbide ceramic spheres: average specific surface area 1.1 m² 2 / g, average particle diameter 5mm.

[0060] Preparation Example 1

[0061] Mixture A is prepared by mixing 30 mL of copper nitrate aqueous solution (0.1 mol / L), 100 mL of cerium ammonium nitrate aqueous solution (0.1 mol / L), and 10 mL of manganese nitrate aqueous solution (0.1 mol / L) and then thoroughly mixing it with 5 g of activated carbon.

[0062] 100g of silicon carbide ceramic balls with a diameter of 5mm were placed in a rotating and heated stainless steel drum. A thermocouple sheath was installed at the bottom of the carrier, and the internal thermocouple was connected to a temperature display instrument to show the temperature changes in real time during the spraying process. The drum speed was adjusted to 15 rpm. When the carrier temperature reached 250℃, mixture A was sprayed onto the carrier through a nozzle at a spraying rate of 0.08 mL / (min·g silicon carbide ceramic balls) until all the solution was completely sprayed. During this process, the carrier temperature gradually increased, reaching 300℃ after spraying. After spraying, the carrier was dried and then calcined in a muffle furnace at 400℃ for 4 hours to obtain catalyst 1.

[0063] Preparation Example 2

[0064] Mixture B is prepared by mixing 30 mL of ferric nitrate aqueous solution (0.1 mol / L), 100 mL of cerium ammonium nitrate aqueous solution (0.1 mol / L), and 10 mL of chromium nitrate aqueous solution (0.1 mol / L) with 5 g of activated carbon and stirring thoroughly.

[0065] 100g of silicon carbide ceramic balls with a diameter of 5mm were placed in a rotating and heated stainless steel drum. A thermocouple sheath was installed at the bottom of the carrier, and the internal thermocouple was connected to a temperature display instrument to show the temperature changes in real time during the spraying process. The drum speed was adjusted to 15 rpm. When the carrier temperature reached 250℃, the above mixture B was sprayed onto the carrier through a nozzle at a spraying rate of 0.08 mL / (min·g silicon carbide ceramic balls) until all the solution was completely sprayed. During this process, the carrier temperature gradually increased, reaching 300℃ after spraying. After spraying, the carrier was dried and then calcined in a muffle furnace at 405℃ for 4 hours to obtain catalyst 2.

[0066] Preparation Example 3

[0067] Mixture C was prepared by mixing 27.6 mL of copper nitrate aqueous solution (0.1 mol / L), 100 mL of cerium ammonium nitrate aqueous solution (0.1 mol / L), and 9.2 mL of manganese nitrate aqueous solution (0.1 mol / L) with 8 g of activated carbon and stirring thoroughly.

[0068] 100g of silicon carbide ceramic balls with a diameter of 5mm were placed in a rotating and heated stainless steel drum. A thermocouple sheath was installed at the bottom of the carrier, and the internal thermocouple was connected to a temperature display instrument to show the temperature changes in real time during the spraying process. The drum speed was adjusted to 17 rpm. When the carrier temperature reached 250℃, mixture C was sprayed onto the carrier through a nozzle at a spraying rate of 0.07 mL / (min·g silicon carbide ceramic balls) until all the solution was completely sprayed. During this process, the carrier temperature gradually increased, reaching 300℃ after spraying. After spraying, the carrier was dried and then calcined in a muffle furnace at 420℃ for 4 hours to obtain catalyst 3.

[0069] Preparation Example 4

[0070] Mixture B is prepared by mixing 25 mL of ferric nitrate aqueous solution (0.1 mol / L), 100 mL of cerium ammonium nitrate aqueous solution (0.1 mol / L), and 11 mL of chromium nitrate aqueous solution (0.1 mol / L) and then thoroughly mixing it with 5 g of activated carbon.

[0071] 100g of silicon carbide ceramic balls with a diameter of 5mm were placed in a rotating and heated stainless steel drum. A thermocouple sheath was installed at the bottom of the carrier, and the internal thermocouple was connected to a temperature display instrument to monitor temperature changes in real time during the spraying process. The drum speed was adjusted to 15 rpm. When the carrier temperature reached 250℃, the mixture B was sprayed onto the carrier through a nozzle at a spraying rate of 0.09 mL / (min·g silicon carbide ceramic balls) until all the solution was completely sprayed. During this process, the carrier temperature gradually increased, reaching 300℃ after spraying. After spraying, the mixture was dried and then calcined in a muffle furnace at 410℃ for 4 hours to obtain catalyst 4.

[0072] Preparation Example 5

[0073] The catalyst was prepared according to the method of Preparation Example 1, except that the amounts of each nitrate solution used were 50 mL, 60 mL and 17.3 mL, respectively.

[0074] Preparation Examples 6-7

[0075] The catalyst was prepared according to the method of Preparation Example 1, except that copper nitrate / manganese nitrate were replaced with equimolar amounts of cerium ammonium nitrate.

[0076] Preparation Examples 8-9

[0077] The catalyst was prepared according to the method of Preparation Example 2, except that ferric nitrate / chromium nitrate was replaced with an equimolar amount of cerium ammonium nitrate.

[0078] Preparation Example 10

[0079] The catalyst was prepared according to the method of Preparation Example 2, except that the silicon carbide ceramic balls were replaced with activated carbon spheres of equal weight.

[0080] Preparation Example 11

[0081] The catalyst was prepared according to the method of Preparation Example 2, except that activated carbon was not used and the weight of the silicon carbide ceramic balls was adjusted to 105g.

[0082] Preparation Example 12

[0083] The catalyst was prepared according to the method of Preparation Example 2, except that the amount of activated carbon used was 20g.

[0084] Preparation Example 13

[0085] The catalyst was prepared according to the method of Preparation Example 1, except that copper nitrate and manganese nitrate were replaced with equimolar amounts of silver nitrate and magnesium nitrate.

[0086] Preparation Example 14

[0087] The catalyst was prepared according to the method of Preparation Example 2, except that ferric nitrate and chromium nitrate were replaced with equimolar amounts of cerium ammonium nitrate.

[0088] Example 1

[0089] 200g of isooctaldehyde and 800g of isooctanoic acid were mixed and placed in an oxidation reactor. 1.2g of sodium isooctanoate was added as a catalyst, and air was introduced as an oxidant. The reaction temperature was 60℃, the pressure was 3MPa, and the reaction was carried out for 2.5 hours to obtain a crude isooctanoic acid solution.

[0090] 30 mL of catalyst 1 was packed into a fixed-bed reactor, and the reactor was purged with nitrogen for 30 min. A crude isooctanoic acid solution and hydrogen gas were then passed together through the fixed-bed reactor containing catalyst 1, with a hydrogen gas to crude isooctanoic acid solution volume ratio of 1:1. The reaction pressure was 0.1 MPa, the temperature was 50 °C, and the hydrogen volume hourly space velocity (HHSV) was 2 h⁻¹. -1 Two hours later, the collection of liquid material from the fixed-bed reactor began.

[0091] The liquid material was distilled using a vacuum distillation apparatus, and the distillate was collected (the collection and distillation apparatus were purged with nitrogen for 30 minutes beforehand). During the distillation process, the temperature of the apparatus was gradually increased from 50°C to 130°C (the heating rate was 5°C / min). The fraction distilled at 100-130°C was collected to obtain isooctanoic acid product.

[0092] Example 2

[0093] 180g of isooctaldehyde and 600g of isooctanoic acid were mixed and placed in an oxidation reactor. 1.1g of sodium isooctanoate was added as a catalyst, and air was introduced as an oxidant. The reaction temperature was 65℃, the pressure was 2.5MPa, and the reaction was carried out for 2 hours to prepare a crude isooctanoic acid solution.

[0094] 30 mL of catalyst 2 was packed into a fixed-bed reactor, and the reactor was purged with nitrogen for 30 minutes. A crude isooctanoic acid solution was then passed through the fixed-bed reactor containing catalyst 2 along with hydrogen gas. The volume ratio of hydrogen gas to crude isooctanoic acid solution was 1:1.2, the pressure was 0.1 MPa, the temperature was 55 °C, and the hydrogen hourly space velocity (HSV) was 2.5 h⁻¹. -1 Two hours later, the liquid material after passing through the fixed-bed reactor was collected. The liquid material was then distilled using a vacuum distillation apparatus, and the distillate was collected (the collection and distillation apparatus were purged with nitrogen for 30 minutes beforehand). During the distillation process, the temperature of the apparatus was gradually increased from 50°C to 130°C (the heating rate was 5°C / min). The fraction distilled at 100-130°C was collected to obtain isooctanoic acid product.

[0095] Example 3

[0096] 200g of isooctaldehyde and 800g of isooctanoic acid were mixed and placed in an oxidation reactor. 1.3g of sodium isooctanoate was added as a catalyst, and air was introduced as an oxidant. The reaction temperature was 63℃, the pressure was 3.2MPa, and the reaction was carried out for 2.1 hours to obtain a crude isooctanoic acid solution.

[0097] The crude isooctanoic acid solution was distilled using a vacuum distillation apparatus, and the distillate was collected (the collection and distillation apparatus were purged with nitrogen for 30 min beforehand). During distillation, the temperature of the apparatus was gradually increased from 40℃ to 130℃ (heating rate of 5℃ / min), and the fraction distilled at 100-130℃ was collected.

[0098] 30 mL of catalyst 2 was packed into a fixed-bed reactor, and the reactor was purged with nitrogen for 30 minutes. The distillate was then passed through the fixed-bed reactor containing catalyst 2 along with hydrogen gas. The volume ratio of hydrogen gas to crude isooctanoic acid solution was 1:0.8, the pressure was 0.1 MPa, the temperature was 50 °C, and the hydrogen volume hourly space velocity was 3 h⁻¹. -1 Two hours later, the liquid material after passing through the fixed-bed reactor was collected to obtain isooctanoic acid product.

[0099] Example 4-13

[0100] The fraction was obtained according to the method of Example 1, except that the catalysts used were the same as those prepared in Preparation Examples 3-12.

[0101] Comparative Example 1

[0102] The fraction was obtained according to the method of Example 1, except that the silicon carbide ceramic balls were not coated with mixture A and were not calcined, but were directly used as a catalyst.

[0103] Comparative Example 2

[0104] Crude isooctanoic acid was prepared according to the method in Example 1, and after obtaining crude isooctanoic acid, it was subjected to intermittent vacuum distillation.

[0105] Comparative Example 3

[0106] After preparing crude isooctanoic acid according to the method in Example 1, no further operations were performed.

[0107] Comparative Example 4-5

[0108] The fraction was obtained according to the method of Example 1, except that the catalyst used was the same as that prepared in Preparation Examples 13-14.

[0109] Test Example 1

[0110] Take 40g of the final product obtained from the examples and comparative examples and place it in a three-necked round-bottom flask equipped with a magnetic stirrer, condenser, and inert gas (nitrogen, 99.9 vol%). At ambient temperature, the sample is bubbled with inert gas while stirring at a rate of 0.2 Nl / min. After 30 minutes, the bubbling rate is reduced to 0.15 Nl / min, and the flask is placed in an oil bath at 225°C. After 4 hours, the bubbling rate is slightly increased to 0.2 Nl / min (to prevent air from being drawn into the flask during cooling), and the heating bath is removed. When the flask cools to ambient temperature, the sample is removed and the APHA color number is measured using a HachLICO 620 colorimeter with a 10 mL cuvette. The APHA color numbers measured for the products of the examples and comparative examples are shown in Table 1.

[0111] Table 1

[0112] serial number APHA color number serial number APHA color number Example 1 3 Example 10 8 Example 2 2 Example 11 12 Example 3 1 Example 12 9 Example 4 2 Example 13 8 Example 5 2 Comparative Example 1 48 Example 6 6 Comparative Example 2 15 Example 7 8 Comparative Example 3 >1000 Example 8 8 Comparative Example 4 14 Example 9 9 Comparative Example 5 14

[0113] As can be seen from the results in Table 1, the isooctanoic acid product prepared using the catalyst provided by this invention has a lower color intensity after simulated long-term storage.

[0114] The preferred embodiments of the present invention have been described in detail above; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combinations of various technical features in any other suitable manner. These simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. A catalyst with color-reducing function, characterized in that, The catalyst includes a support and an active component supported on the support, wherein the active component includes cerium oxide and other metal oxides, wherein the other metal oxides include at least one of copper oxide, iron oxide, chromium oxide and manganese oxide.

2. The catalyst according to claim 1, wherein, The weight ratio of cerium oxide to the support is (0.01-0.05):1, preferably (0.015-0.025):1; And / or, the weight ratio of the other metal oxide to the support is (0.0005-0.01):1, preferably (0.002-0.007):1; And / or, the weight ratio of the copper oxide to the carrier is (0.001-0.005):1, preferably (0.002-0.004):1; And / or, the weight ratio of the iron oxide to the carrier is (0.001-0.005):1, preferably (0.002-0.003):1; And / or, the weight ratio of the chromium oxide to the support is (0.0003-0.003):1, preferably (0.0005-0.0009):1; And / or, the weight ratio of the manganese oxide to the carrier is (0.0005-0.002):1, preferably (0.0006-0.0016):

1.

3. The catalyst according to claim 1, wherein, The other metal oxides are copper oxides and manganese oxides in a weight ratio of 1:(0.1-0.5); Alternatively, the other metal oxides may be iron oxides and chromium oxides in a weight ratio of 1:(0.1-0.5).

4. The catalyst according to any one of claims 1-3, wherein, The carrier comprises activated carbon and silicon carbide, preferably, the weight ratio of activated carbon to silicon carbide is (0.01-0.1):

1.

5. A method for preparing a catalyst, characterized in that, The method includes: attaching a precursor of an active component to a carrier and then calcining it, wherein the active component includes cerium oxide and other metal oxides, wherein the other metal oxides include at least one of copper oxide, iron oxide, chromium oxide and manganese oxide.

6. The method according to claim 5, wherein, The weight ratio of cerium oxide to the support is (0.01-0.05):1, preferably (0.015-0.025):1; And / or, the weight ratio of the other metal oxide to the support is (0.0005-0.01):1, preferably (0.002-0.007):1; And / or, the weight ratio of the copper oxide to the carrier is (0.001-0.005):1, preferably (0.002-0.004):1; And / or, the weight ratio of the iron oxide to the carrier is (0.001-0.005):1, preferably (0.002-0.003):1; And / or, the weight ratio of the chromium oxide to the support is (0.0003-0.003):1, preferably (0.0005-0.0009):1; And / or, the weight ratio of the manganese oxide to the carrier is (0.0005-0.002):1, preferably (0.0006-0.0016):

1.

7. The method according to claim 5, wherein, The other metal oxides are copper oxides and manganese oxides in a weight ratio of 1:(0.1-0.5); Alternatively, the other metal oxides may be iron oxides and chromium oxides in a weight ratio of 1:(0.1-0.5).

8. The method according to claim 5, wherein, The method for attaching the precursor of the active component to the carrier is as follows: the precursor of the active component, activated carbon and water are mixed, and the resulting mixture is sprayed onto silicon carbide.

9. The method according to any one of claims 5-8, wherein, The thermal decomposition temperature of the precursor of the active component is 100-350℃; And / or, the precursor of the active component is a nitrate of a metal element in the active component; And / or, the calcination temperature is 350-1000℃, preferably 390-500℃.

10. A method for preparing isooctanoic acid, characterized in that, The method includes: (1) In the presence of a first catalyst and a solvent, isooctaldehyde reacts with oxygen to undergo a first reaction to obtain crude isooctanoic acid; (2) In the presence of a second catalyst, the crude isooctanoic acid obtained in step (1) is brought into contact with hydrogen to carry out a second reaction to obtain isooctanoic acid product.

11. The method according to claim 10, wherein, In step (1), the first catalyst is a carboxylate, preferably isooctanoate, and more preferably sodium isooctanoate; And / or, the weight ratio of the first catalyst to isooctaldehyde is 1:(100-300); And / or, the solvent is a C1-C10 carboxylic acid, preferably isooctanoic acid; And / or, the molar ratio of isooctaldehyde to oxygen is 1:(0.5-1); And / or, the conditions for the first reaction include: a temperature of 50-70°C, a pressure of 1-10 MPa, and a time of 1-10 h.

12. The method according to claim 10, wherein, The second catalyst is the catalyst according to any one of claims 1-4 and / or the catalyst prepared by the method according to any one of claims 5-9.

13. The method according to any one of claims 10-12, wherein, In step (2), the volume ratio of hydrogen to crude isooctanoic acid is 1:(0.5-2); And / or, the volume hourly space velocity of the hydrogen is 0.5-5 h⁻¹. -1 ; And / or, the conditions for the second reaction include: a temperature of 45-70℃, a pressure of 0.09-0.2MPa, and a time of 0.5-5h.