Ethoxylated catalysts, methods of making and use thereof

Abstract

This invention relates to ethoxylation catalysts, their preparation methods, and their applications. It primarily addresses the problem of high VOC content in the products obtained from existing basic ethoxylation catalysts used in ethoxylation reactions. The technical solution is as follows: an ethoxylation catalyst comprising a main catalyst and a co-catalyst. The main catalyst is an alkali metal hydroxide or an alkali metal alkoxide. The co-catalyst comprises a support and a zero-valent noble metal, wherein the noble metal includes at least one substance selected from the group consisting of Pd, Pt, and Au.

Description

Technical Field

[0001] This invention relates to ethoxylation catalysts, their preparation methods, and their applications. Background Technology

[0002] In the production of nonionic surfactants based on polyoxyethylene ether chains as hydrophilic chains, compounds containing active hydrogen (such as fatty alcohols, alkylphenols, or fatty amines containing NH bonds) are often used as initiators to initiate the polymerization of ethylene oxide in the presence of a catalyst. This catalyst is called an ethoxylation catalyst, the reaction is called an ethoxylation reaction, and the resulting nonionic surfactant product is the ethoxylated product. The ethoxylation reaction is almost quantitatively complete, but a small amount of side reactions still occur, resulting in the presence of volatile organic compounds (VOCs) in the ethoxylated product. In many important applications, the presence of VOCs is detrimental; therefore, reducing VOC content is a goal pursued in this field. Summary of the Invention

[0003] One of the technical problems to be solved by the present invention is to provide a new ethoxylation catalyst, which has the advantage of low VOC content in the ethoxylated product obtained by using the catalyst for ethoxylation reaction.

[0004] An ethoxylation catalyst includes a main catalyst and a co-catalyst, wherein the main catalyst is an alkali metal hydroxide or an alkali metal alkoxide, and the co-catalyst includes a support and a zero-valent noble metal, wherein the noble metal includes at least one substance selected from the group consisting of Pd, Pt and Au.

[0005] Alkali metal hydroxides or alkali metal alkoxides are commonly used catalysts in existing ethoxylation reactions. Our experiments have shown that although the co-catalyst itself does not exhibit catalytic activity in the ethoxylation reaction when used alone without the main catalyst, the ethoxylation catalyst of this invention can significantly reduce the residual VOC in the ethoxylation product because the co-catalyst is used in combination with traditional alkali metal hydroxides (or alkali metal alkoxides).

[0006] In the above technical solution, the preferred alkali metal is potassium or sodium.

[0007] In the above technical solution, the alcohol in the alkali metal alkoxide is preferably a C1 to C3 alcohol.

[0008] In the above technical solution, the preferred carrier is activated carbon.

[0009] In the above technical solution, the activated carbon is preferably powdered activated carbon.

[0010] From the perspective of the efficiency of the co-catalyst, the finer the activated carbon, the better; however, finer activated carbon is more expensive. Considering both the efficiency and cost of the co-catalyst, the particle size of the activated carbon can be, for example, but not limited to, 150–500 mesh, or for example, but not limited to, 160 mesh, 180 mesh, 200 mesh, 250 mesh, 300 mesh, 350 mesh, 400 mesh, 450 mesh, etc. For comparison only, the powdered activated carbon used in the specific embodiments of this invention is produced by Shanghai Lekang Activated Carbon Co., Ltd., and the activated carbon model is 302, with a corresponding particle size of 200–325 mesh.

[0011] In the above technical solution, the main catalyst is calculated as an alkali metal hydroxide containing the same mass of alkali metal, and the co-catalyst is calculated as a noble metal. Preferably, the weight ratio of the main catalyst to the co-catalyst is 50 to 200. For example, but not limited to, the weight ratio of the main catalyst to the co-catalyst is 60, 70, 80, 90, 100, 110, 120, 130, 140, 150, 160, 170, 180, 190, etc.

[0012] In the above technical solution, the content of precious metals in the co-catalyst is preferably 0.5% to 10% by weight. For example, but not limited to, the content of precious metals in the co-catalyst is 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, 5%, 5.5%, 6%, 6.5%, 7%, 7.5%, 8%, 8.5%, 9%, 9.5%, etc., by weight.

[0013] In the above technical solutions, especially when Pd and Au are simultaneously supported in the co-catalyst, Pd and Au have a significant synergistic effect in reducing the VOC residue in the ethoxylation products.

[0014] When Pd and Au have a synergistic effect, there is no particular limitation on the ratio of Pd to Au, and comparable technical effects can be achieved in all cases. However, it is preferred that the weight ratio of Pd to Au is 2 to 10, for example, but not limited to, 2.5, 3, 3.5, 4, 4.4, 5, 5.5, 6, 6.5, 7, 7.5, 8, 8.5, 9, 9.5, etc.

[0015] The second technical problem to be solved by this invention is to provide a method for preparing the above-mentioned catalyst. To solve the above-mentioned technical problem, the technical solution of this invention is as follows:

[0016] The preparation method of the above catalyst may, but is not limited to, obtaining the co-catalyst by a method including the following steps:

[0017] (1) Obtaining a catalyst precursor 1, wherein the catalyst precursor 1 comprises a support and a precipitated compound noble metal supported on the support;

[0018] (2) Reduce the compounded noble metal in the catalyst precursor 1 to elemental form.

[0019] In the above technical solution, the preferred implementation method of step (1) includes the following steps:

[0020] (i) Obtain a solution of a noble metal compound, referred to as solution i; the solvent is preferably water, and the noble metal compound is, for example but not limited to, chloropalladium acid (H2PdCl6), chloroauric acid (HAuCl4), chloroplatinic acid (H2PtCl6), etc.

[0021] (ii) Mix solution i with the carrier to obtain material ii;

[0022] (iii) Adjust the pH of material ii to pH 8-9 to obtain co-catalyst precursor 1.

[0023] In the above technical solution, the reduction in step (2) is preferably gas phase reduction or liquid phase reduction.

[0024] As the name suggests, gas-phase reduction refers to the reduction of the substance to be reduced using a gaseous reducing agent, such as hydrogen gas, which is commonly used in gas-phase reduction. Liquid-phase reduction involves the reduction of the substance to be reduced using a reducing agent in a solvent, typically those that are soluble in the solvent. Commonly used reducing agents for liquid-phase reduction include, but are not limited to, hydrazine hydrate, alkali metal borohydrides (such as sodium borohydride or potassium borohydride), formaldehyde, sodium formate, or potassium formate, etc. These reduction techniques are common in existing technologies. For this invention, as long as the goal is to reduce a combined noble metal to a zero-valent noble metal element, those skilled in the art can choose between gas-phase and liquid-phase reduction, and can reasonably select the process conditions for the reduction reaction, achieving comparable technical effects without requiring creative effort.

[0025] In the preparation of the co-catalyst in the specific implementation method, unless otherwise specified, the typical temperature of a laboratory air-conditioned room is 26±2℃.

[0026] The key technology of this invention lies in the selection of the ethoxylation catalyst components. There are no particular limitations on the preparation method of the ethoxylation catalyst; all methods can achieve comparable technical effects without requiring creative effort. For example:

[0027] The main catalyst and the co-catalyst can be mixed outside the ethoxylation reactor to obtain the ethoxylation catalyst, which is then added to the ethoxylation reactor.

[0028] Alternatively, the main catalyst and the co-catalyst can be added separately to the ethoxylation reactor and mixed in situ within the reactor to obtain the ethoxylation catalyst. There is no particular restriction on the order in which the main catalyst and the co-catalyst are added to the ethoxylation reactor before the ethoxylation reaction begins.

[0029] The third technical problem to be solved by the present invention is to provide the application of the above-mentioned catalyst.

[0030] To solve the third technical problem mentioned above, the technical solution of the present invention is as follows:

[0031] The application of the ethoxylation catalyst described in any one of the technical solutions to one of the above-mentioned technical problems, or the ethoxylation catalyst obtained by any one of the preparation methods described in the technical solution to another of the above-mentioned technical problems, in ethoxylation production.

[0032] The key technology of this invention is the selection of catalyst components. As for how to use the ethoxylation catalyst to carry out the ethoxylation reaction between fatty alcohols and ethylene oxide, there is no technical obstacle for those skilled in the art. It can be reasonably selected within the scope of existing technology without the need for creative labor.

[0033] For example, the initiators used can be fatty alcohols, alkylphenols, or fatty amines containing NH bonds. These compounds all contain active hydrogen and have the structural basis for initiating ethylene oxide polymerization. The ethoxylated products obtained by ethoxylation using fatty alcohols as initiators are referred to in the art as fatty alcohol polyoxyethylene ethers, the ethoxylated products obtained by alkylphenols as initiators are referred to in the art as alkylphenol polyoxyethylene ethers, and the ethoxylated products obtained by fatty amines as initiators are referred to in the art as fatty amine polyoxyethylene ethers. In the daily chemical industry, the most commonly used initiator is a fatty alcohol, preferably a C8-C20 fatty alcohol; the fatty alcohol can be a straight-chain alcohol or a branched-chain alcohol; the fatty alcohol can be a saturated alcohol or an unsaturated alcohol; the fatty alcohol can be a primary alcohol or a secondary alcohol.

[0034] The following example, using the ethoxylation process with fatty alcohols as initiators, illustrates the non-limiting process conditions of the catalyst of this invention, for example:

[0035] A method for synthesizing fatty alcohol ethoxylates includes the following steps: in the presence of an ethoxylation catalyst as described in any one of the technical solutions of one of the above-mentioned technical problems or an ethoxylation catalyst obtained by any one of the preparation methods of the technical solution of another of the above-mentioned technical problems, using fatty alcohol as an initiator, ethylene oxide undergoes a ring-opening polymerization reaction to obtain fatty alcohol polyoxyethylene ether.

[0036] The key technology of this invention lies in the selection of the ethoxylation catalyst component. Under these circumstances, those skilled in the art can rationally select specific ethoxylation reaction process conditions. For example:

[0037] In the above technical solution, the preferred temperature for the ethoxylation reaction is 110℃ to 180℃. For example, but not limited to, temperatures for the ethoxylation reaction include 115℃, 120℃, 125℃, 130℃, 135℃, 140℃, 145℃, 150℃, 155℃, 160℃, 165℃, 170℃, and 175℃. More preferably, the temperature for the ethoxylation reaction is 120℃ to 160℃.

[0038] In the above technical solution, the pressure of the ethoxylation reaction is preferably 0.1MPa to 0.4MPa, such as, but not limited to, 0.15MPa, 0.2MPa, 0.25MPa, 0.3MPa, 0.35MPa, etc.

[0039] In the above technical solution, based on the total weight of fatty alcohol and ethylene oxide added to the ethoxylation reaction system, the amount of ethoxylation catalyst is preferably 0.1% to 1%, for example, but not limited to, 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, etc.

[0040] For comparison purposes only, the fatty alcohols used in the specific embodiments are all 3,5,5-trimethyl-1-hexanol, also known as isononol.

[0041] In the specific implementation method, the amount of co-catalyst used is calculated based on the precious metals it contains.

[0042] In the above technical solutions, the preferred molar ratio of ethylene oxide to fatty alcohol in the ethoxylation reaction system is 2–40, for example, but not limited to, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 20, 25, 30, 35, etc. A more common molar ratio in production is 3–10.

[0043] After the ethoxylation reaction is completed, the filter residue obtained by filtering the ethoxylation product contains used co-catalyst. The precious metals in the filter residue can be recovered by techniques well known in the art, or the co-catalyst can be recovered by washing the filter residue and then added back into the formulation of the ethoxylation catalyst.

[0044] The method for measuring VOC residues in the specific embodiments of the present invention is in accordance with GB / T 35862-2018 (Determination of Volatile Organic Compound Residues in Surfactants by Headspace Gas Chromatography-Mass Spectrometry (GC-MS)); the pH of the ethoxylated product in the specific embodiments is determined by GB / T 6368-2008 (Determination of pH of Aqueous Solutions of Surfactants by Potentiometric Method); and the content of noble metals in the co-catalyst in the specific embodiments is measured by ICP (Inductively Coupled Plasma Spectrometer).

[0045] The present invention will now be described in detail through specific embodiments. Detailed Implementation

[0046]

Example 1

[0047] 1. Preparation of co-catalysts

[0048] Take 100 parts by weight of chloropalladium acid aqueous solution (Pd weight concentration of 6.50%), add 100 parts by weight of powdered activated carbon, stir for 30 minutes, adjust the pH to 8.5 with 10% sodium carbonate aqueous solution, and let stand for 24 hours. Then, while stirring, add 35 parts by weight of 85% hydrazine hydrate, let stand for 24 hours, filter, wash the filter cake with deionized water until the filtrate shows a negative reaction for chloride ions when tested with 1% silver nitrate aqueous solution. Dry the filter cake at 80℃ for 6 hours to obtain the co-catalyst Pd / C. The noble metal weight content in the co-catalyst is 6.04% Pd.

[0049] 2. Synthesis of isononyl alcohol polyoxyethylene (5) ether

[0050] Add 288 g (2 mol) of isononol, 2.0 g of KOH, and 0.020 g of co-catalyst (based on precious metals) to a 2-liter high-pressure reactor equipped with a stirrer. Seal the reactor and start stirring. Replace the air in the reactor with nitrogen four times. Then, introduce ethylene oxide into the reactor, controlling the reaction temperature at 130 °C and the reaction pressure at 0.25 MPa, until the total amount of ethylene oxide introduced is 440 g (10 mol), completing the main reaction. After stopping the ethylene oxide feed, maintain the reactor temperature at 130°C for aging reaction until the reactor pressure no longer decreases, indicating that the aging reaction is complete. Vacuum the reactor at -0.095 MPa and 110°C for 45 min, cool to 85°C, neutralize to pH 5.5 with 40% phosphoric acid aqueous solution, stir at 85°C for 60 min, vacuum the reactor at -0.095 MPa and 110°C for 45 min, cool to 80°C, filter until clear, and obtain isononyl alcohol polyoxyethylene (5) ether product.

[0051] The residual amount of volatile organic compounds in the isononyl alcohol polyoxyethylene (5) ether product was measured to be 21 mg·kg. -1 .

[0052]

Example 2

[0053] 1. Preparation of co-catalysts

[0054] Take 100 parts by weight of chloroplatinic acid aqueous solution (Pt weight concentration of 6.50%), add 100 parts by weight of powdered activated carbon, stir for 30 minutes, adjust the pH to 8.5 with 10% sodium carbonate aqueous solution, and let stand for 24 hours. Then, while stirring, add 35 parts by weight of 85% hydrazine hydrate, let stand for 24 hours, filter, wash the filter cake with deionized water until the filtrate shows a negative reaction for chloride ions when tested with 1% silver nitrate aqueous solution. Dry the filter cake at 80℃ for 6 hours to obtain the co-catalyst Pt / C. The precious metal weight content in the co-catalyst is: Pt 5.99%.

[0055] 2. Synthesis of isononyl alcohol polyoxyethylene (5) ether

[0056] Add 288 g (2 mol) of isononol, 2.0 g of KOH, and 0.020 g of co-catalyst (based on precious metals) to a 2-liter high-pressure reactor equipped with a stirrer. Seal the reactor and start stirring. Replace the air in the reactor with nitrogen four times. Then, introduce ethylene oxide into the reactor, controlling the reaction temperature at 130 °C and the reaction pressure at 0.25 MPa, until the total amount of ethylene oxide introduced is 440 g (10 mol), completing the main reaction. After stopping the ethylene oxide feed, maintain the reactor temperature at 130°C for aging reaction until the reactor pressure no longer decreases, indicating that the aging reaction is complete. Vacuum the reactor at -0.095 MPa and 110°C for 45 min, cool to 85°C, neutralize to pH 5.5 with 40% phosphoric acid aqueous solution, stir at 85°C for 60 min, vacuum the reactor at -0.095 MPa and 110°C for 45 min, cool to 80°C, filter until clear, and obtain isononyl alcohol polyoxyethylene (5) ether product.

[0057] The residual amount of volatile organic compounds in the isononyl alcohol polyoxyethylene (5) ether product was measured to be 32 mg·kg. -1 .

[0058]

Example 3

[0059] 1. Preparation of co-catalysts

[0060] Take 100 parts by weight of chloroauric acid aqueous solution (Au weight concentration of 6.90%), add 100 parts by weight of powdered activated carbon, stir for 30 minutes, adjust the pH to 8.5 with 10% sodium carbonate aqueous solution, and let stand for 24 hours. Then, while stirring, add 35 parts by weight of 85% hydrazine hydrate, let stand for 24 hours, filter, wash the filter cake with deionized water until the filtrate shows a negative reaction for chloride ions when tested with 1% silver nitrate aqueous solution. Dry the filter cake at 80℃ for 6 hours to obtain the co-catalyst Au / C. The noble metal weight content in the co-catalyst is: Au 5.97%.

[0061] 2. Synthesis of isononyl alcohol polyoxyethylene (5) ether

[0062] Add 288 g (2 mol) of isononol, 2.0 g of KOH, and 0.020 g of co-catalyst (based on precious metals) to a 2-liter high-pressure reactor equipped with a stirrer. Seal the reactor and start stirring. Replace the air in the reactor with nitrogen four times. Then, introduce ethylene oxide into the reactor, controlling the reaction temperature at 130 °C and the reaction pressure at 0.25 MPa, until the total amount of ethylene oxide introduced is 440 g (10 mol), completing the main reaction. After stopping the ethylene oxide feed, maintain the reactor temperature at 130°C for aging reaction until the reactor pressure no longer decreases, indicating that the aging reaction is complete. Vacuum the reactor at -0.095 MPa and 110°C for 45 min, cool to 85°C, neutralize to pH 5.5 with 40% phosphoric acid aqueous solution, stir at 85°C for 60 min, vacuum the reactor at -0.095 MPa and 110°C for 45 min, cool to 80°C, filter until clear, and obtain isononyl alcohol polyoxyethylene (5) ether product.

[0063] The residual amount of volatile organic compounds in the isononyl alcohol polyoxyethylene (5) ether product was measured to be 26 mg·kg. -1 .

[0064]

Example 4

[0065] 1. Preparation of co-catalysts

[0066] Take 100 parts by weight of a mixed aqueous solution of chloropalladium-chloroauric acid (Pd weight concentration 5.40%, Au weight concentration 1.10%), add 100 parts by weight of powdered activated carbon, stir for 30 minutes, adjust the pH to 8.5 with a 10% sodium carbonate aqueous solution, and let stand for 24 hours. Then, while stirring, add 35 parts by weight of 85% hydrazine hydrate, let stand for 24 hours, filter, wash the filter cake with deionized water until the filtrate shows a negative reaction for chloride ions when tested with a 1% silver nitrate aqueous solution. Dry the filter cake at 80℃ for 6 hours to obtain the co-catalyst Pd-Au / C. The noble metal weight content in the co-catalyst is: Pd 5.03%, Au 0.93%.

[0067] 2. Synthesis of isononyl alcohol polyoxyethylene (5) ether

[0068] Add 288 g (2 mol) of isononol, 2.0 g of KOH, and 0.020 g of co-catalyst (based on precious metals) to a 2-liter high-pressure reactor equipped with a stirrer. Seal the reactor and start stirring. Replace the air in the reactor with nitrogen four times. Then, introduce ethylene oxide into the reactor, controlling the reaction temperature at 130 °C and the reaction pressure at 0.25 MPa, until the total amount of ethylene oxide introduced is 440 g (10 mol), completing the main reaction. After stopping the ethylene oxide feed, maintain the reactor temperature at 130°C for aging reaction until the reactor pressure no longer decreases, indicating that the aging reaction is complete. Vacuum the reactor at -0.095 MPa and 110°C for 45 min, cool to 85°C, neutralize to pH 5.5 with 40% phosphoric acid aqueous solution, stir at 85°C for 60 min, vacuum the reactor at -0.095 MPa and 110°C for 45 min, cool to 80°C, filter until clear, and obtain isononyl alcohol polyoxyethylene (5) ether product.

[0069] The residual amount of volatile organic compounds in the isononyl alcohol polyoxyethylene (5) ether product was measured to be 7 mg·kg. -1 .

[0070]

Example 5

[0071] 1. Preparation of co-catalysts

[0072] Take 100 parts by weight of a mixed aqueous solution of chloropalladium-chloroauric acid (Pd weight concentration 4.26%, Au weight concentration 2.30%), add 100 parts by weight of powdered activated carbon, stir for 30 minutes, adjust the pH to 8.5 with a 10% sodium carbonate aqueous solution, and let stand for 24 hours. Then, while stirring, add 35 parts by weight of 85% hydrazine hydrate, let stand for 24 hours, filter, wash the filter cake with deionized water until the filtrate shows a negative chloride ion reaction when tested with a 1% silver nitrate aqueous solution. Dry the filter cake at 80℃ for 6 hours to obtain the co-catalyst Pd-Au / C. The noble metal weight content in the co-catalyst is: Pd 3.96%, Au 1.97%.

[0073] 2. Synthesis of isononyl alcohol polyoxyethylene (5) ether

[0074] Add 288 g (2 mol) of isononol, 2.0 g of KOH, and 0.020 g of co-catalyst (based on precious metals) to a 2-liter high-pressure reactor equipped with a stirrer. Seal the reactor and start stirring. Replace the air in the reactor with nitrogen four times. Then, introduce ethylene oxide into the reactor, controlling the reaction temperature at 130 °C and the reaction pressure at 0.25 MPa, until the total amount of ethylene oxide introduced is 440 g (10 mol), completing the main reaction. After stopping the ethylene oxide feed, maintain the reactor temperature at 130°C for aging reaction until the reactor pressure no longer decreases, indicating that the aging reaction is complete. Vacuum the reactor at -0.095 MPa and 110°C for 45 min, cool to 85°C, neutralize to pH 5.5 with 40% phosphoric acid aqueous solution, stir at 85°C for 60 min, vacuum the reactor at -0.095 MPa and 110°C for 45 min, cool to 80°C, filter until clear, and obtain isononyl alcohol polyoxyethylene (5) ether product.

[0075] The residual amount of volatile organic compounds in the isononyl alcohol polyoxyethylene (5) ether product was measured to be 15 mg·kg. -1 .

[0076]

Example 6

[0077] 1. Preparation of co-catalysts

[0078] Take 100 parts by weight of a mixed aqueous solution of chloropalladium-chloroauric acid (Pd weight concentration 5.67%, Au weight concentration 0.80%), add 100 parts by weight of powdered activated carbon, stir for 30 minutes, adjust the pH to 8.5 with a 10% sodium carbonate aqueous solution, and let stand for 24 hours. Then, while stirring, add 35 parts by weight of 85% hydrazine hydrate, let stand for 24 hours, filter, wash the filter cake with deionized water until the filtrate shows a negative reaction for chloride ions when tested with a 1% silver nitrate aqueous solution. Dry the filter cake at 80℃ for 6 hours to obtain the co-catalyst Pd-Au / C. The noble metal weight content in the co-catalyst is: Pd 5.28%, Au 0.67%.

[0079] 2. Synthesis of isononyl alcohol polyoxyethylene (5) ether

[0080] Add 288 g (2 mol) of isononol, 2.0 g of KOH, and 0.020 g of co-catalyst (based on precious metals) to a 2-liter high-pressure reactor equipped with a stirrer. Seal the reactor and start stirring. Replace the air in the reactor with nitrogen four times. Then, introduce ethylene oxide into the reactor, controlling the reaction temperature at 130 °C and the reaction pressure at 0.25 MPa, until the total amount of ethylene oxide introduced is 440 g (10 mol), completing the main reaction. After stopping the ethylene oxide feed, maintain the reactor temperature at 130°C for aging reaction until the reactor pressure no longer decreases, indicating that the aging reaction is complete. Vacuum the reactor at -0.095 MPa and 110°C for 45 min, cool to 85°C, neutralize to pH 5.5 with 40% phosphoric acid aqueous solution, stir at 85°C for 60 min, vacuum the reactor at -0.095 MPa and 110°C for 45 min, cool to 80°C, filter until clear, and obtain isononyl alcohol polyoxyethylene (5) ether product.

[0081] The residual amount of volatile organic compounds in the isononyl alcohol polyoxyethylene (5) ether product was measured to be 13 mg·kg. -1 .

[0082]

Comparative Example 1

[0083] Synthesis of isononyl alcohol polyoxyethylene (5) ether

[0084] Add 288 g (2 mol) of isononol and 2.0 g of KOH to a 2-liter high-pressure reactor equipped with a stirrer. Seal the reactor and start stirring. Replace the air in the reactor with nitrogen four times. Then, introduce ethylene oxide into the reactor, controlling the reaction temperature at 130 °C and the reaction pressure at 0.25 MPa, until the total amount of ethylene oxide introduced is 440 g (10 mol), completing the main reaction. After stopping the ethylene oxide feed, maintain the reactor temperature at 130°C for aging reaction until the reactor pressure no longer decreases, indicating that the aging reaction is complete. Vacuum the reactor at -0.095 MPa and 110°C for 45 min, cool to 85°C, neutralize to pH 5.5 with 40% phosphoric acid aqueous solution, stir at 85°C for 60 min, vacuum the reactor at -0.095 MPa and 110°C for 45 min, cool to 80°C, filter until clear, and obtain isononyl alcohol polyoxyethylene (5) ether product.

[0085] The residual amount of volatile organic compounds in the isononyl alcohol polyoxyethylene (5) ether product was measured to be 264 mg·kg. -1 .

[0086] [Comparative Example 2]

[0087] Synthesis of isononyl alcohol polyoxyethylene (5) ether

[0088] Add 288 g (2 mol) of isononol, 2.0 g of KOH, and 0.32 g of activated carbon to a 2-liter high-pressure reactor equipped with a stirrer. Seal the reactor and start stirring. Replace the air in the reactor with nitrogen four times. Then, introduce ethylene oxide into the reactor, controlling the reaction temperature at 130 °C and the reaction pressure at 0.25 MPa, until the total amount of ethylene oxide introduced is 440 g (10 mol), completing the main reaction. After stopping the ethylene oxide feed, maintain the reactor temperature at 130°C for aging reaction until the reactor pressure no longer decreases, indicating that the aging reaction is complete. Vacuum the reactor at -0.095 MPa and 110°C for 45 min, cool to 85°C, neutralize to pH 5.5 with 40% phosphoric acid aqueous solution, stir at 85°C for 60 min, vacuum the reactor at -0.095 MPa and 110°C for 45 min, cool to 80°C, filter until clear, and obtain isononyl alcohol polyoxyethylene (5) ether product.

[0089] The residual amount of volatile organic compounds in the isononyl alcohol polyoxyethylene (5) ether product was measured to be 239 mg·kg. -1 .

[0090] [Comparative Example 3]

[0091] 288 g (2 mol) of isononol and 2.0 g of the co-catalyst from Example 4 (based on the co-catalyst itself, not the precious metals in the co-catalyst) were added to a 2-liter high-pressure reactor equipped with a stirrer. The reactor was sealed and the stirrer was turned on. The air in the reactor was replaced four times with nitrogen. The reaction temperature was controlled at 130°C. Ethylene oxide was introduced into the reactor, but attempts to stop the addition of ethylene oxide were made. The pressure in the reactor did not decrease after 1 hour, indicating that the co-catalyst itself has no catalytic activity for the ethoxylation reaction in the absence of a co-catalyst.

Claims

1. Use of an ethoxylation catalyst in ethoxylation production, the ethoxylation catalyst comprising a main catalyst and a co-catalyst, the main catalyst being an alkali metal hydroxide or an alkali metal alkoxide, the co-catalyst comprising a carrier and a zero-valent noble metal, the noble metal comprising Pd and Au; the weight ratio of the main catalyst to the co-catalyst being 50-200, the main catalyst being an alkali metal hydroxide containing the same mass of alkali metal, the co-catalyst being the noble metal.

2. Use according to claim 1, characterized in that The weight ratio of Pd to Au is 2-10.

3. Use according to claim 1, characterized in that, The alkali metal is potassium or sodium.

4. The use according to claim 1, characterized in that The alcohol in the alkali metal alkoxide is a C1-C3 alcohol.

5. The use according to claim 1, characterized in that, The carrier is activated carbon.

6. Use according to claim 5, characterized in that, The activated carbon is powdered activated carbon.

7. Use according to claim 6, characterized in that, The particle size of the activated carbon is 150-500 mesh.

8. The use according to claim 1, characterized in that The content of the noble metal in the co-catalyst is 0.5-10% by weight.

9. Use according to any one of claims 1 to 8, characterized in that In the preparation method of the catalyst, the co-catalyst is obtained by a method comprising the following steps: (1) obtaining a co-catalyst precursor 1, the co-catalyst precursor 1 comprising a carrier and a precipitated noble metal compound supported on the carrier; (2) reducing the noble metal compound in the co-catalyst precursor 1 to an element.

10. Use according to claim 9, characterized in that In the preparation method of the catalyst, the implementation method of step (1) comprises the following steps: (i) obtaining a noble metal compound solution, referred to as solution i; (ii) mixing solution i with the carrier to obtain material ii; (iii) adjusting the pH of material ii to pH 8-9 to obtain the co-catalyst precursor 1.

11. Use according to claim 9, characterized in that, The reduction in step (2) is gas-phase reduction or liquid-phase reduction.