Method for improving hydrothermal stability of supported catalyst, product obtained by method and application of product

Abstract

The invention relates to a method for improving the hydrothermal stability of a supported catalyst, which comprises the following steps: placing the supported catalyst in an oxygen-enriched chelating agent solution for dipping treatment, and then washing with a solvent until the pH value of eluate is close to neutral or no oxygen-enriched chelating agent exists in the eluate to obtain the supported catalyst with high hydrothermal stability. The method is simple and convenient to operate and mild in condition, the hydrothermal stability of the catalyst can be effectively improved, and the service life of the catalyst is prolonged. The catalyst treated by the method disclosed by the invention is good in hydrothermal stability, and still keeps high raw material conversion rate and product selectivity after continuously operating for 200h in a heterogeneous catalytic reaction system.

Description

[Technical field]

[0001] The present invention belongs to the technical field of catalysts. More specifically, the present invention relates to a method for improving the hydrothermal stability of a supported catalyst, a product obtained by the method, and a use of the product. [Background technology]

[0002] A catalyst is a substance that changes the reaction rate but does not change the total standard Gibbs free energy of the reaction. The phenomenon of accelerating or slowing down the rate of a chemical reaction due to the intervention of a catalyst is called catalysis. In a catalytic reaction, the catalyst reacts chemically with the reactants, changing the reaction pathway and thus reducing the activation energy of the reaction, which is why the catalyst can increase the reaction rate. In order to give full play to the role of the catalyst, we need the catalyst to be in full contact with the reactants, and the specific surface area of ​​the catalyst itself becomes an important parameter. Generally speaking, the larger the specific surface area of ​​the catalyst, the larger the interface with the reactants, which is more conducive to the catalyst to function.

[0003] During use, catalysts will be subjected to complex chemical reaction environments such as high temperature, high pressure, and redox, which will damage the structure and function of the catalyst itself, leading to catalyst deactivation. Among them, hydrothermal aging is one of the main causes of catalyst deactivation.

[0004] The so-called hydrothermal aging is the aging phenomenon caused by the long-term chemical reaction of the catalyst in the presence of high-temperature and high-pressure water vapor. Hydrothermal aging will lead to the loss of active sites on the catalyst surface, changes in the surface structure, resulting in reduced catalyst activity and changes in the selectivity of the reaction products. The presence of water molecules will cause the collapse and peeling of the catalyst crystal structure, causing the catalyst to lose stability and accelerate the aging process. The loss of activity of the catalyst due to hydrothermal aging will shorten the catalyst life, cause cost waste, and also have an impact on the environment.

[0005] In order to solve the defects of the prior art, the inventor has finally completed the present invention after a lot of experiments and research. [Summary of the invention]

[0006] [Technical issues to be solved]

[0007] The object of the present invention is to provide a method for improving the hydrothermal stability of a supported catalyst.

[0008] Another object of the present invention is to provide a product obtained by the method for improving the hydrothermal stability of a supported catalyst.

[0009] Another object of the present invention is to provide the use of the product.

[0010] [Technical solution]

[0011] The present invention is achieved through the following technical solutions.

[0012] The invention relates to a method for improving the hydrothermal stability of a supported catalyst.

[0013] The implementation steps of this method are as follows:

[0014] The supported catalyst is immersed in an oxygen-rich chelating agent solution with a concentration of 0.02% to 5.00% by weight at a temperature of 0°C to 100°C for 0.1 to 2.0 hours, and then the immersed supported catalyst is washed with a solvent until the pH of the washing solution is neutral or the washing solution is free of oxygen-rich chelating agent, thereby obtaining a supported catalyst with high hydrothermal stability.

[0015] According to a preferred embodiment of the present invention, the supported catalyst is a nickel alumina catalyst or a platinum alumina catalyst.

[0016] According to another preferred embodiment of the present invention, the carrier of the supported catalyst is one or more carriers selected from pseudo-boehmite, boehmite, aluminum hydroxide dry gel, γ-alumina or magnesium aluminum spinel.

[0017] According to another preferred embodiment of the present invention, the oxygen-enriched chelating agent is one or more oxygen-enriched chelating agents selected from citric acid, diamine hydrogen citrate, oxalic acid, succinic acid, glutaric acid, ethylenediaminetetraacetic acid or tartaric acid.

[0018] According to another preferred embodiment of the present invention, the solvent of the oxygen-enriched chelating agent solution is one or more solvents selected from water, methanol, ethanol or ethyl acetate.

[0019] According to another preferred embodiment of the present invention, the ratio of supported catalyst in grams to oxygen-rich chelating agent solution in milliliters is 1:1-20.

[0020] According to another preferred embodiment of the present invention, the solvent used for washing the impregnated supported catalyst is one or more solvents selected from water, methanol, ethanol or ethyl acetate.

[0021] The invention also relates to a supported catalyst with high hydrothermal stability obtained by the method.

[0022] The present invention also relates to the use of the high hydrothermal stability supported catalyst in preparing 1,3-propylene glycol by hydrogenating 3-hydroxypropanal.

[0023] According to a preferred embodiment of the present invention, the preparation method of 1,3-propylene glycol is as follows:

[0024] According to the weight ratio of 3-hydroxypropanal to water of 0.05-0.95:1 and 4.5-50% of the above-mentioned high hydrothermal stability supported catalyst based on the weight of 3-hydroxypropanal, 3-hydroxypropanal and hydrogen are reacted in a water solvent in the presence of the catalyst at a temperature of 30°C to 160°C and a pressure of 0.1MPa to 10.0MPa for 20 to 60 minutes, and then 1,3-propylene glycol is separated and purified.

[0025] The present invention will be described in more detail below.

[0026] The invention relates to a method for improving the hydrothermal stability of a supported catalyst.

[0027] In the present invention, a supported catalyst should be understood as a catalyst in which the active components are uniformly dispersed and supported on a carrier. Such a catalyst has high activity, high selectivity and good stability and is widely used in the field of chemistry and chemical engineering.

[0028] Hydrothermal stability should be understood as the property of a supported catalyst that its structure is not destroyed and maintains sufficient activity under high temperature and water vapor conditions.

[0029] The implementation steps of this method are as follows:

[0030] The supported catalyst is immersed in an oxygen-rich chelating agent solution with a concentration of 0.02% to 5.00% by weight at a temperature of 0°C to 100°C for 0.1 to 2.0 hours, and then the immersed supported catalyst is washed with a solvent until the pH of the washing solution is neutral or the washing solution is free of oxygen-rich chelating agent, thereby obtaining a supported catalyst with high hydrothermal stability.

[0031] The supported catalyst involved in the present invention is a nickel alumina catalyst or a platinum alumina catalyst. Of course, the present invention also involves some other existing supported catalysts, but other supported catalysts can withstand the treatment method of the present invention, and their performance is also improved. These supported catalysts are also within the protection scope of the present invention.

[0032] According to the present invention, the carrier of the supported catalyst is one or more carriers selected from pseudo-boehmite, boehmite, aluminum hydroxide dry gel, γ-alumina or magnesium aluminum spinel, which are all products currently sold on the market, such as the pseudo-boehmite carrier sold by Shanghai Xunkai New Materials Technology Co., Ltd. under the trade name of supported nickel catalyst SNCAT-2100TE, and the γ-alumina carrier sold by Shaanxi Ruike New Materials Co., Ltd. under the trade name of platinum alumina catalyst. Of course, the carrier can also be the carrier of other existing supported catalysts mentioned above, and these carriers are also within the scope of protection of the present invention.

[0033] In the present invention, oxygen-rich chelating agent should be understood as an oxygen-rich chemical substance that can form a stable complex with metal ions. It has multiple coordination sites, can form multiple coordination bonds with metal ions, and can form complexes with unoccupied orbitals in metal ions through lone pairs of electrons. These coordination bonds stabilize metal ions in the form of charge transfer, chemical bonds or coordination bonds, change the electronic structure and coordination environment around metal ions, and thus have an important impact on the properties of metals.

[0034] The oxygen-enriched chelating agent is one or more oxygen-enriched chelating agents selected from citric acid, diamine hydrogen citrate, oxalic acid, succinic acid, glutaric acid, ethylenediaminetetraacetic acid or tartaric acid, all of which are products currently sold on the market, such as products sold by Suzhou Xiangsong Chemical Co., Ltd. under the trade name of citric acid and oxalic acid, products sold by Ningxiang Xinyang Chemical Co., Ltd. under the trade name of diamine hydrogen citrate, products sold by Zibo Sanwei Chemical Plant under the trade name of ethylenediaminetetraacetic acid, products sold by Shanghai Nanxiang Reagent Co., Ltd. under the trade name of succinic acid, products sold by Shandong Suihua Biotechnology Co., Ltd. under the trade name of glutaric acid, and products sold by Henan Wanshan New Materials Technology Co., Ltd. under the trade name of anhydrous tartaric acid.

[0035] In the present invention, the solvent in the oxygen-enriched chelating agent solution is one or more solvents selected from water, methanol, ethanol or ethyl acetate, and methanol, ethanol or ethyl acetate are all products currently sold on the market, such as the product sold under the trade name of methanol by Anhui Nanmu Chemical Co., Ltd. or the ethyl acetate sold under the trade name of ethyl acetate, and the product sold under the trade name of ethanol by Jiangsu Nantong Hongchang Chemical Co., Ltd.

[0036] In the present invention, the concentration of the oxygen-enriched chelating agent solution is 0.02% to 5.00% by weight. If the concentration of the oxygen-enriched chelating agent solution is lower than 0.02%, the effect of improving the hydrothermal stability of the supported catalyst is poor; if the concentration of the oxygen-enriched chelating agent solution is higher than 5.00%, the effect of improving the hydrothermal stability of the supported catalyst is not significantly improved, but the processing cost is increased. Therefore, the concentration of the oxygen-enriched chelating agent solution is suitable for 0.02 to 5.00%, preferably 0.50 to 4.50%, and more preferably 1.50 to 3.50%.

[0037] According to the present invention, the ratio of supported catalyst in grams to oxygen-enriched chelating agent solution in milliliters is 1:1 to 20. If the ratio of supported catalyst to oxygen-enriched chelating agent solution is greater than 1:1, insufficient amount of oxygen-enriched chelating agent impregnation will result, affecting the impregnation effect; if the ratio of supported catalyst to oxygen-enriched chelating agent solution is less than 1:20, the amount of oxygen-enriched chelating agent solution is too much, which will cause supported catalyst particles to aggregate, reduce the porosity of supported catalyst, and affect its catalytic activity. Therefore, it is suitable that the ratio of supported catalyst to oxygen-enriched chelating agent solution is 1:1 to 20, preferably 1:5 to 18, and more preferably 1:8 to 10.

[0038] In the present invention, the supported catalyst is immersed in the oxygen-enriched chelating agent solution at a temperature of 0°C to 100°C for 0.1 to 2.0 hours. When the immersion time is within the range, if the immersion temperature is lower than 0°C, the immersion temperature is too low and the hydrothermal stability is poorly improved; if the immersion temperature is higher than 100°C, the immersion temperature is too high, which will cause the oxygen-enriched chelating agent to be unevenly distributed in the supported catalyst, resulting in decreased activity of the impregnated catalyst or pore blockage. Therefore, it is reasonable to have an immersion temperature of 0 to 100°C, preferably 20 to 80°C, and more preferably 40 to 60°C. When the immersion temperature is within the range, if the immersion time is shorter than 0.1h, the immersion effect is insufficient and the hydrothermal stability is poorly improved; if the immersion time is longer than 2.0h, the effect of extending the immersion time on improving the hydrothermal stability of the supported catalyst is not obvious. Therefore, the appropriate immersion time is 0.1 to 2.0 h, preferably 0.5 to 1.5 h, and more preferably 0.8 to 1.2 h.

[0039] The impregnated supported catalyst is washed with a solvent until the pH of the washing solution is neutral or the washing solution is free of oxygen-enriched chelating agent, thereby obtaining the supported catalyst with high hydrothermal stability.

[0040] In the present invention, the main function of washing the impregnated supported catalyst with a solvent is to wash away the free oxygen-rich chelating agent on the catalyst surface;

[0041] In the present invention, the solvent used for washing the impregnated supported catalyst is one or more solvents selected from water, methanol, ethanol or ethyl acetate. These solvents have been described above and will not be described again here.

[0042] Washing with solvent until the pH of the washing liquid is neutral indicates that the free oxygen-rich chelating agent on the catalyst surface has been washed away; washing with solvent until there is no oxygen-rich chelating agent in the washing liquid indicates that the free oxygen-rich chelating agent on the catalyst surface has been washed away; the oxygen-rich chelating agent in the washing liquid is determined according to conventional liquid chromatography.

[0043] The hydrothermal stability of the supported catalyst of the present invention is determined according to the change in the specific surface area of ​​the catalyst after the hydrothermal reaction. Specifically, a hydrothermal reactor sold by Anhui Kemi Instrument Co., Ltd. under the trade name HTG Universal Hydrothermal Reactor is used, and the supported catalyst of the present invention is added to water according to a ratio of 1:20 to 100 in grams of the supported catalyst of the present invention to water in milliliters, and then a hydrothermal reaction is carried out for 4 hours at a temperature of 180°C and a pressure of 2.0MPa, and then a drying device sold by Suzhou Taino Oven Manufacturing Co., Ltd. under the trade name of a drying oven is used to dry the catalyst to a water content of less than 0.5% by weight at a temperature of 100 to 110°C, and the dried supported catalyst is measured under conventional conditions using a BET specific surface area detector sold by Bester Instrument Technology (Beijing) Co., Ltd. under the trade name of a specific surface area and pore size analyzer to obtain the specific surface area of ​​the supported catalyst of the present invention.

[0044] The specific surface area of ​​the supported catalyst raw material used in the present invention is determined by the same method.

[0045] The results calculated according to the following formula can reflect the effect of the method of the present invention on improving the hydrothermal stability of the supported catalyst:

[0046] Improvement of hydrothermal stability of supported catalyst (%) = (AB) / A

[0047] Where:

[0048] A-specific surface area of ​​the supported catalyst of the present invention;

[0049] B-specific surface area of ​​supported catalyst raw material;

[0050] The invention also relates to a supported catalyst with high hydrothermal stability obtained by the method.

[0051] The present invention also relates to the use of the high hydrothermal stability supported catalyst in preparing 1,3-propylene glycol by hydrogenating 3-hydroxypropanal.

[0052] The preparation method of 1,3-propylene glycol of the present invention is as follows:

[0053] According to the weight ratio of 3-hydroxypropanal to water of 0.05-0.95:1 and 4.5-50% of the above-mentioned high hydrothermal stability supported catalyst based on the weight of 3-hydroxypropanal, 3-hydroxypropanal and hydrogen are reacted in a water solvent in the presence of the catalyst at a temperature of 30°C to 160°C and a pressure of 0.1MPa to 10.0MPa for 20 to 60 minutes, and then 1,3-propylene glycol is separated and purified.

[0054] The supported catalyst with improved hydrothermal stability of the present invention can be verified by a life experiment of a hydrogenation catalytic reaction system, and details are shown in the specific implementation method section.

[0055] Specifically, the conversion rate and selectivity calculated by the following formula are used to evaluate the catalytic performance of the hydrothermal stability supported catalyst of the present invention:

[0056] Conversion rate (%) = raw material conversion amount / total raw material amount × 100%

[0057] Where:

[0058] The feedstock conversion amount is the amount of 3-hydroxypropanal converted to 1,3-propylene glycol;

[0059] The total amount of raw materials is the amount of 3-hydroxypropanal used;

[0060] Selectivity (%) = the amount of raw materials consumed to obtain the target product / the amount of converted raw materials × 100%

[0061] Where:

[0062] The amount of raw materials consumed is the amount of 3-hydroxypropanal raw materials consumed in the reaction;

[0063] The amount of converted raw materials is the amount of raw materials consumed in the reaction to obtain 1,3-propylene glycol;

[0064] The amounts of the raw materials and products are determined by conventional liquid chromatography analysis.

[0065] The catalytic performance of the supported catalyst of the present invention is evaluated by the feedstock conversion rate and the target product selectivity, and the details are shown in the specific implementation method section.

[0066] [Beneficial Effects]

[0067] The invention has the following beneficial effects: the invention is easy to operate, has mild conditions, can effectively improve the hydrothermal stability of the catalyst, and prolongs the service life of the catalyst. The hydrothermal stability of the catalyst treated by the method for improving the hydrothermal stability of the supported catalyst of the invention is good, and after continuous operation for 200 hours in a multiphase catalytic reaction system, a high raw material conversion rate and a high product selectivity are still maintained. [Specific implementation method]

[0068] The present invention will be better understood through the following examples.

[0069] Example 1: Method for improving the hydrothermal stability of supported catalysts

[0070] The implementation steps of this embodiment are as follows:

[0071] The citric acid oxygen-enriched chelating agent sold by Suzhou Xiangsong Chemical Co., Ltd. under the trade name of citric acid is prepared into an oxygen-enriched chelating agent aqueous solution with a concentration of 0.02% by weight using a water solvent. The supported catalyst (whose carrier is pseudo-boehmite) sold by Shanghai Xunkai New Material Technology Co., Ltd. under the trade name of supported nickel catalyst SNCAT-2100TE is placed in the oxygen-enriched chelating agent aqueous solution. The ratio of the supported catalyst in grams to the oxygen-enriched chelating agent aqueous solution in milliliters is 1:1. The catalyst is immersed for 2.0 hours at a temperature of 0°C, and then the immersed supported catalyst is washed with a water solvent until the pH of the washing liquid is neutral, thereby obtaining a supported catalyst with high hydrothermal stability.

[0072] Example 2: Method for improving the hydrothermal stability of supported catalysts

[0073] The implementation steps of this embodiment are as follows:

[0074] The diamine hydrogen citrate oxygen-enriched chelating agent sold by Ningxiang Xinyang Chemical Co., Ltd. under the trade name diamine hydrogen citrate is prepared into an aqueous solution of diamine hydrogen citrate with a concentration of 5.00% by weight using an aqueous solvent. The supported catalyst (whose carrier is pseudo-boehmite) sold by Shanghai Xunkai New Material Technology Co., Ltd. under the trade name supported nickel catalyst SNCAT-2100TE is placed in the oxygen-enriched chelating agent aqueous solution. The ratio of the supported catalyst in grams to the oxygen-enriched chelating agent aqueous solution in milliliters is 1:20. The catalyst is immersed for 0.1 h at a temperature of 100°C, and then the immersed supported catalyst is washed with an aqueous solvent until the pH of the washing liquid is neutral, thereby obtaining a supported catalyst with high hydrothermal stability.

[0075] Example 3: Method for improving the hydrothermal stability of supported catalysts

[0076] The implementation steps of this embodiment are as follows:

[0077] An oxygen-enriched chelating agent of oxalic acid sold by Suzhou Xiangsong Chemical Co., Ltd. under the trade name of oxalic acid and an oxygen-enriched chelating agent of succinic acid sold by Shanghai Nanxiang Reagent Co., Ltd. under the trade name of succinic acid are prepared into an oxygen-enriched chelating agent ethanol solution having a concentration of 0.05% oxalic acid and 0.10% succinic acid by weight using an ethanol solvent sold by Jiangsu Nantong Hongchang Chemical Co., Ltd. under the trade name of ethanol. A supported catalyst (whose carrier is γ-alumina) sold by Shaanxi Ruike New Materials Co., Ltd. under the trade name of platinum alumina catalyst is placed in the oxygen-enriched chelating agent ethanol solution, and the ratio of the supported catalyst in grams to the oxygen-enriched chelating agent ethanol solution in milliliters is 1:8. The catalyst is immersed for 0.5 h at a temperature of 60°C, and then the immersed supported catalyst is washed with an ethanol solvent until the washing liquid is free of oxygen-enriched chelating agent, thereby obtaining a supported catalyst with high hydrothermal stability.

[0078] Example 4: Method for improving the hydrothermal stability of supported catalysts

[0079] The implementation steps of this embodiment are as follows:

[0080] The glutaric acid oxygen-enriched chelating agent sold by Shandong Suihua Biotechnology Co., Ltd. under the trade name of glutaric acid and the tartaric acid oxygen-enriched chelating agent sold by Henan Wanshan New Materials Technology Co., Ltd. under the trade name of anhydrous tartaric acid are prepared into an oxygen-enriched chelating agent methanol solution with a concentration of 0.5% glutaric acid and 1.5% tartaric acid by weight using methanol solvent sold by Anhui Nanmu Chemical Co., Ltd. under the trade name of methanol. The supported catalyst (whose carrier is γ-alumina) sold by Shaanxi Ruike New Materials Co., Ltd. under the trade name of platinum alumina catalyst is placed in the oxygen-enriched chelating agent methanol solution, and the ratio of grams of supported catalyst to milliliters of oxygen-enriched chelating agent methanol solution is 1:10. The catalyst is immersed for 1.2 hours at a temperature of 80°C, and then the immersed supported catalyst is washed with methanol solvent until there is no oxygen-enriched chelating agent in the washing liquid, thereby obtaining a supported catalyst with high hydrothermal stability.

[0081] Embodiment 5:

[0082] The implementation steps of this embodiment are as follows:

[0083] The ethylenediaminetetraacetic acid oxygen-enriched chelating agent sold by Zibo Sanwei Chemical Factory under the trade name of ethylenediaminetetraacetic acid is prepared into an oxygen-enriched chelating agent ethyl acetate solution with a concentration of 2.5% by weight of ethylenediaminetetraacetic acid using an ethyl acetate solvent sold by Anhui Nanmu Chemical Co., Ltd. under the trade name of ethyl acetate. A supported catalyst (whose carrier is pseudo-boehmite) sold by Shanghai Xunkai New Material Technology Co., Ltd. under the trade name of supported nickel catalyst SNCAT-2100TE is placed in the oxygen-enriched chelating agent ethyl acetate solution, and the ratio of the supported catalyst in grams to the oxygen-enriched chelating agent ethyl acetate solution in milliliters is 1:5. The catalyst is immersed for 1.5 hours at a temperature of 40°C, and then the immersed supported catalyst is washed with an ethyl acetate solvent until there is no oxygen-enriched chelating agent in the washing liquid, thereby obtaining a supported catalyst with high hydrothermal stability.

[0084] The catalysts obtained after the treatment in Examples 1 to 5 were placed in a hydrothermal reactor respectively, and a hydrothermal reaction was carried out for 4 hours at a temperature of 180° C. and a pressure of 2.0 MPa. The catalysts were then dried to determine their specific surface areas.

[0085] Comparative Example 1:

[0086] A supported catalyst (whose carrier is pseudo-boehmite) sold by Shanghai Xunkai New Material Technology Co., Ltd. under the trade name of supported nickel catalyst SNCAT-2100TE is placed in a hydrothermal reactor and subjected to a hydrothermal reaction at a temperature of 180°C and a pressure of 2.0 MPa for 4 hours, followed by drying at 100°C to a water content of 0.2% by weight, and its specific surface area is measured according to the method described in the specification of this application.

[0087] Comparative Example 2:

[0088] A supported catalyst (whose carrier is alumina) sold by Shaanxi Ruike New Materials Co., Ltd. under the trade name of platinum alumina catalyst is placed in a hydrothermal reactor and subjected to a hydrothermal reaction at a temperature of 180°C and a pressure of 2.0 MPa for 4 hours, followed by drying at 110°C to a water content of 0.1% by weight, and its specific surface area is measured according to the method described in the specification of this application.

[0089] The specific surface area analysis results of the samples obtained in Examples 1 to 5 and Comparative Examples 1 to 2 and the catalysts used are listed in Table 1.

[0090] Table 1: Catalyst specific surface area analysis results

[0091]

[0092]

[0093] The data listed in Table 1 show that, compared with existing catalysts, the catalysts treated by the method of the present invention for improving the hydrothermal stability of supported catalysts still maintain a high specific surface area after the hydrothermal reaction and have good hydrothermal stability. The specific surface area of ​​the catalysts not treated by the method of the present invention decreases significantly after the hydrothermal reaction, indicating that their hydrothermal stability is significantly worse.

[0094] Application Example 1:

[0095] The catalysts obtained in Examples 1 to 5 and Comparative Examples 1 to 2 were subjected to a 200-hour life experiment of hydrogenation reaction: 3-hydroxypropanal with a concentration of 10% by weight and hydrogen were hydrogenated in a water solvent in the presence of the catalyst at a temperature of 150° C. and a pressure of 8.0 MPa for 200 hours. The 3-hydroxypropanal conversion rate and 1,3-propylene glycol selectivity were determined according to the method described in the specification of the present application, and the analysis results are listed in Table 2.

[0096] Table 2: Hydrogenation reaction 200h life test results

[0097] sample 3-Hydroxypropanal conversion rate % 1,3-Propanediol selectivity % Example 1 99.75 99.99 Example 2 99.90 99.99 Example 3 99.95 99.99 Example 4 99.96 99.99 Example 5 99.62 99.99 Comparative Example 1 79.5 98.5 Comparative Example 2 80.3 98.6

[0098] The results listed in Table 2 show that the supported catalyst treated by the method of the present invention has high catalytic activity in a multiphase catalytic reaction system for preparing 1,3-propylene glycol by hydrogenation of 3-hydroxypropanal with water as solvent, and still maintains high raw material conversion rate and product selectivity after continuous operation for 200 hours, while the raw material conversion rate and product selectivity of the catalyst not treated by the method of the present invention are significantly reduced after continuous operation for 200 hours.

Claims

1. A method for improving the hydrothermal stability of a supported catalyst, characterized in that The implementation steps of this method are as follows: The supported catalyst is immersed in an oxygen-rich chelating agent solution with a concentration of 0.02% to 5.00% by weight at a temperature of 0°C to 100°C for 0.1 to 2.0 hours, and then the immersed supported catalyst is washed with a solvent until the pH of the washing solution is neutral or the washing solution is free of oxygen-rich chelating agent, thereby obtaining a supported catalyst with high hydrothermal stability.

2. The method according to claim 1, characterized in that The supported catalyst is a nickel alumina catalyst or a platinum alumina catalyst.

3. The method according to claim 1 or 2, characterized in that The carrier of the supported catalyst is one or more carriers selected from pseudo-boehmite, boehmite, aluminum hydroxide dry gel, γ-alumina or magnesium aluminum spinel.

4. The method according to claim 1, characterized in that The oxygen-enriched chelating agent is one or more oxygen-enriched chelating agents selected from citric acid, diamine hydrogen citrate, oxalic acid, succinic acid, glutaric acid, ethylenediaminetetraacetic acid or tartaric acid.

5. The method according to claim 1, characterized in that The solvent of the oxygen-enriched chelating agent solution is one or more solvents selected from water, methanol, ethanol or ethyl acetate.

6. The method according to claim 1, characterized in that The ratio of supported catalyst in grams to oxygen-enriched chelating agent solution in milliliters is 1:1 to 20.

7. The method according to claim 1, characterized in that The solvent used for washing the impregnated supported catalyst is one or more solvents selected from water, methanol, ethanol or ethyl acetate.

8. A supported catalyst with high hydrothermal stability obtained according to the method according to any one of claims 1 to 7.

9. Use of the high hydrothermal stability supported catalyst according to claim 8 in the preparation of 1,3-propylene glycol by hydrogenation of 3-hydroxypropanal.

10. The use according to claim 9, characterized in that The preparation method of 1,3-propylene glycol is as follows: According to the weight ratio of 3-hydroxypropanal to water of 0.05-0.95:1 and 4.5-50% of the above-mentioned high hydrothermal stability supported catalyst based on the weight of 3-hydroxypropanal, 3-hydroxypropanal and hydrogen are reacted in a water solvent in the presence of the catalyst at a temperature of 30°C to 160°C and a pressure of 0.1MPa to 10.0MPa for 20 to 60 minutes, and then 1,3-propylene glycol is separated and purified.

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