A highly efficient hydrothermal and acid-resistant catalyst for the oxidation of polyols, its preparation method and application.

Abstract

The application provides a high-efficiency water-resistant and acid-resistant catalyst for catalyzing polyol oxidation and a preparation method and application thereof, and relates to the technical field of polyol oxidation catalysts.The high-efficiency water-resistant and acid-resistant catalyst for catalyzing polyol oxidation comprises a main active component, an additive and a modified carrier;the main active component is at least one of Au, Pt and Pd;the additive is at least one of Mn, Fe, Co, Ni, Cu, Sb and Bi;and the carrier is at least one of SiO2, Al2O3, TS-1 molecular sieve, ZSM-5 molecular sieve and activated carbon.The catalyst carrier is modified and a specific kind of additive is added, so that the activity and stability of the catalyst are enhanced, and the catalyst has excellent water-resistant and acid-resistant performance.The catalyst raw material is easy to obtain, the preparation process is simple, the reaction process is environmentally friendly, the catalyst is convenient to recover and reusable, and the catalyst has a good industrial application prospect.

Description

Technical Field

[0001] This invention relates to the field of polyol oxidation catalyst technology, and in particular to a highly efficient hydrothermal and acid-resistant catalyst for polyol oxidation, its preparation method, and its application. Background Technology

[0002] The widespread use of petroleum-based chemicals has exacerbated the consumption of fossil fuels, leading to increasingly severe environmental pollution problems. These issues have made research on biomass, an abundant and renewable resource, increasingly important. Polyols are high-value-added chemical raw materials produced from biomass resources such as lignocellulose, sugars, and oils through a series of processing techniques (such as pyrolysis and hydrogenation). They can effectively alleviate the problems of fossil fuel consumption and environmental pollution.

[0003] The oxidation of alcohols is an important method for preparing unsaturated carbonyl compounds such as ketones and acids. Among the 12 biomass-based platform compounds of high-value-added chemicals proposed by the U.S. Department of Energy, the vast majority are polyols (such as glycerol and sorbitol) and the carboxylic acid oxidation products of polyols (such as gluconic acid and 3-hydroxypropionic acid). These chemicals have very important applications in many important industrial fields, such as the synthesis of polymer materials, pharmaceuticals, and food.

[0004] Research reports on the field of polyol oxidation have been emerging continuously. In terms of catalyst design, researchers use metal or non-metal elements such as K, La, P, and Bi to modify the support or active components of supported metal catalysts to achieve catalyst modification treatment, thereby improving the catalyst's activity, service life, and stability.

[0005] For example, invention patent CN 104645983 A adds lanthanum, cerium, and zirconium compounds to hydrated alumina and calcines it at 500–1000°C for a period of time to obtain an alumina support with high thermal stability. Then, it loads one or more of copper, silver, manganese, palladium, and platinum elements to obtain a high-performance circulating gas purification catalyst. Invention patent CN 111774087 A uses bismuth salts, organic precursors, and a nitrogen source to prepare a bismuth-modified porous carbon support through mechanical mixing and calcination, and then loads noble metals to obtain a solid catalyst. Invention patent CN 114054031… Patent A discloses a catalyst for the oxidation of polyols, including an active component and a support; the active component includes Fe element, and the support includes a metal oxide of IVB element, wherein the support is modified with a transition metal other than Fe. The preparation method of the catalyst includes: (1) preparing a transition metal modified TiO2 support by sol-gel method; (2) impregnating the modified TiO2 support with ferric nitrate aqueous solution to obtain a precursor solution; (3) drying and grinding the precursor solution and then calcining it in a muffle furnace to obtain the desired catalyst.

[0006] In addition, numerous research reports have documented the design of bimetallic catalysts. For example, patent CN114534723A discloses a catalyst and its preparation method for the selective oxidation of ethylene glycol to glycolic acid. It comprises palladium as the active component, activated carbon as the support, and bismuth and cerium dioxide as auxiliary catalysts. The palladium content is 0.1%–1.5% of the support weight, and the total content of bismuth and cerium dioxide, based on cerium content, is 0.25%–1.5% of the support weight. Patent CN114029058A discloses a catalyst for the catalytic oxidation of glycerol to 1,3-dihydroxyacetone, comprising an active component, an auxiliary agent, and a support. The active component includes Au, and the auxiliary agent includes one or more of Mg, Ca, Ba, Sr, Ni, Co, Cu, and Fe. The support is ZnO. Patent CN117753468... Patent A discloses a supported catalyst for the catalytic oxidation of glycerol to lactic acid, its preparation method, and its application. The supported catalyst includes an active metal, a promoter metal, and a support. The active metal includes Pt, the promoter metal includes one or more of Zn, K, Co, Cu, and Ni, and the support is a molecular sieve containing heteroatoms. The content of Lewis acid in the molecular sieve containing heteroatoms is 0.1–0.3 mmol / g.

[0007] The synergistic effect of promoters and noble metal main active components in bimetallic catalysts not only reduces the cost of the catalyst but also improves its performance and increases reaction efficiency. Regarding feedstock selection, most studies focus on the oxidation of C2-C4 polyols, with limited research on the catalytic oxidation of polyols with higher carbon numbers.

[0008] The performance of a catalyst is a crucial indicator of its quality. Different reactions and reaction conditions require different catalyst performance characteristics, such as temperature resistance and corrosion resistance. Among existing polyol catalytic oxidation catalysts, research on their hydrothermal and acid resistance properties is scarce. For example, patent CN 114534723A discloses a method for preparing a carbon-supported Pt-Bi-CeO2 catalyst for the oxidation of ethylene glycol to glycolic acid, using flake or granular activated carbon to improve the catalyst's alkali resistance. Patents CN 118079951A, CN 108911961A, and CN 105439831A disclose catalysts for the catalytic oxidation of polyols to acids under alkali-free or non-alkali conditions, but they do not address the catalyst's hydrothermal and acid resistance.

[0009] For the oxidation reaction of polyols, since most research and industrial applications use raw materials in aqueous solution form and the reaction products are accompanied by acid production, the reaction system requires the catalyst to have good hydrothermal and acid resistance to ensure stable catalytic activity during use. Therefore, improving the hydrothermal and acid resistance of the catalyst while ensuring good catalytic activity, selectivity, and stability is of great significance for the preparation of high-value-added chemicals from polyols. Summary of the Invention

[0010] In view of this, the present invention provides a highly efficient hydrothermal and acid-resistant catalyst for the oxidation of polyols, its preparation method, and its application. The present invention improves the activity and stability of the catalyst through catalyst support modification and the addition of specific types of auxiliary agents, enabling it to maintain good catalytic activity and stability even in an aqueous reaction system with an acidic pH. Furthermore, the raw materials are readily available, the preparation process is simple, environmentally friendly, and easy to recycle, showing promising prospects for industrial application.

[0011] A highly efficient hydrothermal and acid-resistant catalyst for the oxidation of polyols, the catalyst comprising a main active component, an auxiliary agent, and a modified support.

[0012] Preferably, the main active component is at least one of Au, Pt, and Pd, more preferably Pt; the auxiliary agent is at least one of Mn, Fe, Co, Ni, Cu, Sb, and Bi, more preferably Cu; the modified support is obtained by modifying a support; the support is at least one of SiO2, Al2O3, TS-1 molecular sieve, ZSM-5 molecular sieve, and activated carbon, more preferably SiO2; the mass ratio of the main active component to the modified support is (0.5-3):100; and the mass of the auxiliary agent accounts for 0.1%-10% of the total mass of the catalyst.

[0013] Preferably, the modified carrier is prepared by the following method:

[0014] The modifier is mixed with the carrier, dried, and calcined to obtain the modified carrier;

[0015] The modifier is a silane coupling agent; the mass ratio of the modifier to the carrier is 1:10; the drying temperature is 70℃-100℃, preferably 70℃, and the drying time is 5-10h, preferably 5h; the calcination temperature is 500℃, and the calcination time is 4-6h, preferably 4h.

[0016] The second aspect of this invention is to provide a method for preparing a hydrothermal and acid-resistant catalyst for the oxidation of polyols with high efficiency, wherein the preparation method is an impregnation reduction method or a solvent reduction method.

[0017] Preferably, the impregnation reduction method for preparing the highly efficient hydrothermal and acid-resistant catalyst for polyol oxidation includes the following steps:

[0018] After the modified carrier is dried, a precursor solution of the main active component and a metal salt solution of the auxiliary agent are added dropwise, stirred evenly, aged and dried to obtain powder A;

[0019] Powder A was calcined, reduced under a hydrogen atmosphere, cooled, and ground to obtain a highly efficient hydrothermal and acid-resistant catalyst for the oxidation of polyols.

[0020] The drying temperature of the modified carrier is 70℃-100℃, preferably 70℃, and the drying time is 5-10h, preferably 5h; the precursor of the main active component is the nitrate, sulfate or chloride of the corresponding main active component; the solvent of the solution is at least one of water, ethanol, and isopropanol; the calcination temperature is 500℃, and the calcination time is 4-6h, preferably 4h; the reduction temperature is 400℃, and the reduction time is 5-6h, preferably 5h.

[0021] Preferably, the solvent reduction method for preparing the highly efficient hydrothermal and acid-resistant catalyst for polyol oxidation includes the following steps:

[0022] The modified carrier was mixed with a solvent to obtain suspension A;

[0023] The precursor solution of the main active component and the metal salt solution of the auxiliary agent were added to suspension A and stirred evenly to obtain mixture B;

[0024] Sodium borohydride solution was added dropwise to mixture B. After the reaction, the mixture was allowed to stand for aging, filtered, and dried to obtain a highly efficient hydrothermal and acid-resistant catalyst for the oxidation of polyols.

[0025] The precursor of the main active component is a nitrate, sulfate, or chloride of the corresponding main active component; the solvent of the solution is at least one of water, ethanol, and isopropanol; the reaction is carried out under stirring conditions, the reaction temperature is 70℃-80℃, preferably 70℃, and the reaction time is 8-10h, preferably 8h; the aging temperature is 25℃, the aging time is 8-12h, preferably 8h; the drying temperature is 60℃-120℃, and the drying time is 1-24h.

[0026] A third aspect of the present invention is to provide the application of the catalyst in the catalytic oxidation of polyols under hydrothermal and acidic conditions.

[0027] Preferably, the polyol catalytic oxidation reaction is carried out with water as solvent and air or O2 as oxidant under vigorous stirring (1000 r / min), the reaction temperature is 50℃-200℃, the reaction pressure is atmospheric pressure to 5 MPa, and the reaction time is 1-24 h.

[0028] Compared with the prior art, the beneficial technical effects of the present invention are as follows:

[0029] This invention improves the loading capacity and stability of the main active component by modifying the catalyst support.

[0030] This invention improves the dispersion of the main active component in the support by adding specific types of additives, reduces the amount of the main active component to save on catalyst production costs, and enhances the activity and stability of the catalyst through the interaction between the additives and the main active component.

[0031] The catalyst prepared by this invention has good hydrothermal and acid resistance in the oxidation reaction of polyols, that is, it can still maintain good catalytic activity and stability for the catalytic oxidation of polyols when the reaction system is aqueous and the pH is acidic.

[0032] The catalyst of this invention has readily available reaction raw materials, a simple preparation process, an environmentally friendly reaction process, and is easy to recover and reuse, thus showing good prospects for industrial application. Detailed Implementation

[0033] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0034] The first aspect of this invention is to provide a hydrothermal and acid-resistant catalyst for the oxidation of polyols with high efficiency, the catalyst comprising a main active component, an auxiliary agent and a modified support;

[0035] The main active component is at least one of Au, Pt, and Pd, preferably Pt; the auxiliary agent is at least one of Mn, Fe, Co, Ni, Cu, Sb, and Bi, preferably Cu; the modified support is obtained by modifying a support; the support is at least one of SiO2, Al2O3, TS-1 molecular sieve, ZSM-5 molecular sieve, and activated carbon, preferably SiO2; the mass ratio of the main active component to the support is (0.5-3):100; the mass of the auxiliary agent accounts for 0.1%-10% of the total mass of the catalyst.

[0036] The method for preparing the modified carrier of the present invention is as follows:

[0037] The modifier is mixed with the carrier, dried, and calcined to obtain the modified carrier;

[0038] The modifier is a silane coupling agent; the mass ratio of the modifier to the carrier is 1:10; the drying temperature is 70℃-100℃, preferably 70℃, and the drying time is 5-10h, preferably 5h; the calcination temperature is 500℃, and the calcination time is 4-6h, preferably 4h.

[0039] The second aspect of this invention is to provide a method for preparing a hydrothermal and acid-resistant catalyst for the oxidation of polyols with high efficiency, wherein the preparation method is an impregnation reduction method or a solvent reduction method.

[0040] The impregnation and reduction process for the highly efficient hydrothermal and acid-resistant catalyst for polyol oxidation described in this invention includes the following steps:

[0041] After the modified carrier is dried, a precursor solution of the main active component and a metal salt solution of the auxiliary agent are added dropwise, stirred evenly, aged and dried to obtain powder A;

[0042] Powder A was calcined, reduced under a hydrogen atmosphere, cooled, and ground to obtain a highly efficient hydrothermal and acid-resistant catalyst for the oxidation of polyols.

[0043] The drying temperature of the modified carrier is 70℃-100℃, preferably 70℃, and the drying time is 5-10h, preferably 5h; the precursor of the main active component is the nitrate, sulfate or chloride of the corresponding main active component; the solvent of the solution is at least one of water, ethanol, and isopropanol; the calcination temperature is 500℃, and the calcination time is 4-6h, preferably 4h; the reduction temperature is 400℃, and the reduction time is 5-6h, preferably 5h.

[0044] The solvent reduction method for preparing the highly efficient hydrothermal and acid-resistant catalyst for polyol oxidation described in this invention includes the following steps:

[0045] The modified carrier was mixed with a solvent to obtain suspension A;

[0046] The precursor solution of the main active component and the metal salt solution of the auxiliary agent were added to suspension A and stirred evenly to obtain mixture B;

[0047] Sodium borohydride solution was added dropwise to mixture B. After the reaction, the mixture was allowed to stand for aging, filtered, and dried to obtain a highly efficient hydrothermal and acid-resistant catalyst for the oxidation of polyols.

[0048] The precursor of the main active component is a nitrate, sulfate, or chloride of the corresponding main active component; the solvent of the solution is at least one of water, ethanol, and isopropanol; the reaction is carried out under stirring conditions, the reaction temperature is 70℃-80℃, preferably 70℃, and the reaction time is 8-10h, preferably 8h; the aging temperature is 25℃, the aging time is 8-12h, preferably 8h; the drying temperature is 60℃-120℃, and the drying time is 1-24h.

[0049] A third aspect of the present invention is to provide the application of the catalyst in the catalytic oxidation of polyols under hydrothermal and acidic conditions.

[0050] The polyol catalytic oxidation reaction is carried out with water as solvent and air or O2 as oxidant under vigorous stirring (1000 r / min), the reaction temperature is 50℃-200℃, the reaction pressure is atmospheric pressure to 5 MPa, and the reaction time is 1-24 h.

[0051] To further illustrate the present invention, the following embodiments are provided for detailed description. All raw materials used in the following embodiments of the present invention are commercially available.

[0052] Unless otherwise specified, all experiments were repeated three times, and the results are expressed as averages.

[0053] Example 1: Preparation method of the modified carrier, the steps are as follows:

[0054] 10g of silica, alumina, TS-1 molecular sieve, ZSM-5 molecular sieve and activated carbon were mixed with 1g of silane coupling agent KH550 respectively. After being mixed evenly, the mixture was dried at 70℃ for 5h and then calcined at 500℃ for 4h to obtain the modified support.

[0055] Example 2: Preparation method of Pt-Cu / SiO2 catalyst, the steps are as follows:

[0056] (1) Dry 5g of the modified SiO2 support in Example 1 at 70°C for 5h for later use. Dissolve 0.275g of chloroplatinic acid hexahydrate in 25mL of deionized water, stir evenly, and add it dropwise to the dried support. Stir vigorously throughout the process to ensure that the support fully absorbs the solution and obtain impregnation solution 1.

[0057] (2) Dissolve 0.292g of copper nitrate in 25ml of anhydrous ethanol, stir well and add dropwise to impregnation solution 1, stirring vigorously throughout the process to ensure that the carrier fully absorbs the solution, thus obtaining impregnation solution 2.

[0058] (3) The impregnation solution 2 was aged overnight at 25°C and dried at 70°C for 5 hours. Then, it was calcined in a muffle furnace at 500°C for 4 hours. Finally, the catalyst was reduced in a tube furnace at 400°C for 5 hours in a hydrogen atmosphere. After cooling, it was ground in a ball mill at a ball-to-material ratio of 15:1 and a speed of 50 rpm for 30 minutes to obtain the Pt-Cu / SiO2 catalyst. The Pt content in this catalyst was 2 wt.%, and the Cu content was 1.5 wt.%.

[0059] Example 3: Preparation method of Pt-Cu / SiO2 catalyst, the steps are as follows:

[0060] (1) Mix 5g of the modified SiO2 support from Example 1 with 150mL of deionized water to obtain suspension 1;

[0061] (2) Take 0.275g of chloroplatinic acid hexahydrate and 0.292g of copper nitrate and add them to suspension 1. Stir for 10 minutes to form mixture 2.

[0062] (3) Dissolve 0.07 g of sodium borohydride in 100 mL of deionized water to prepare a sodium borohydride solution. Add the solution dropwise to the suspension at a rate of 3-5 drops / second. After the addition is complete, stir the mixture at a constant temperature of 70 °C for 8 h, allow it to stand for aging for 8 h, filter the solution, and dry it at 70 °C for 12 h to obtain the Pt-Cu / SiO2 catalyst. The Pt content in this catalyst is 2 wt.%, and the Cu content is 1.5 wt.%.

[0063] Example 4

[0064] 0.216 g of palladium nitrate and 0.173 g of chloroauric acid were dissolved in 25 ml of deionized water, and the remaining steps were the same as in Example 2. Finally, Pd-Cu / TiO2 catalyst and Au-Cu / TiO2 catalyst were obtained, respectively.

[0065] Example 5

[0066] 0.246 g of manganese nitrate, 0.545 g of ferric nitrate nonahydrate, 0.373 g of cobalt nitrate hexahydrate, 0.374 g of nickel nitrate, and 0.076 g of antimony chloride were dissolved in 25 mL of anhydrous ethanol, respectively. 0.143 g of bismuth nitrate was dissolved in 25 mL of isopropanol. The remaining steps were the same as in Example 2. Finally, Pt-Mn / SiO2 catalysts, Pt-Fe / SiO2 catalysts, Pt-Co / SiO2 catalysts, Pt-Ni / SiO2 catalysts, Pt-Sb / SiO2 catalysts, and Pt-Bi / SiO2 catalysts were obtained, respectively. In all of these catalysts, the Pt content was 2 wt.%, and the content of the promoters (Mn, Fe, Co, Ni, Sb, Bi) was 1.5 wt.%.

[0067] Example 6

[0068] 0.069 g, 0.137 g, and 0.550 g of chloroplatinic acid hexahydrate were weighed and dissolved in 25 ml of deionized water, respectively. The remaining steps were the same as in Example 2. Pt-Cu / SiO2 catalysts with active component contents of 0.5 wt.%, 1 wt.%, and 4 wt.% were finally prepared and designated as Pt(0.5)-Cu / SiO2 catalyst, Pt(1)-Cu / SiO2 catalyst, and Pt(2)-Cu / SiO2 catalyst, respectively.

[0069] Example 7

[0070] Using 5g of dried modified alumina, modified TS-1 molecular sieve, ZSM-5 molecular sieve, and activated carbon as supports, and following the same steps as in Example 2, Pt-Cu / Al2O3 catalyst, Pt-Cu / TS-1 catalyst, Pt-Cu / ZSM-5 catalyst, and Pt-Cu / AC catalyst were finally prepared. In all of these catalysts, the Pt content was 2 wt.% and the Cu content was 1.5 wt.%.

[0071] Test Example 1

[0072] The catalysts prepared in Examples 2-7 were applied to the oxidation of glycerol to glyceric acid / lactic acid, as follows:

[0073] 0.2 g of each catalyst and 25 mL of 0.1 mol / L glycerol aqueous solution were added separately to a 25 mL high-pressure reactor, and oxygen was introduced at 0.5 MPa for reaction. The reaction temperature was 80 °C, the stirring rate was 1000 r / min, and the reaction time was 9 h. After the reaction, the reaction solution was filtered using a disposable syringe and a syringe filter. The filtrate was subjected to chromatographic analysis, and the glycerol conversion rate, glyceric acid selectivity, and lactic acid selectivity were calculated. The results are shown in Table 1.

[0074] Table 1 Results of glycerol oxidation experiments

[0075]

[0076] In the above experiments, the reaction products were acidic, and the pH of the reaction system was 1.7-2.5.

[0077] Based on the data in Table 1, the following conclusions can be drawn:

[0078] The Pt-Cu / SiO2 prepared by impregnation yields the highest glycerol conversion and glyceric acid / lactic acid selectivity;

[0079] The catalytic performance of Pt-Cu / SiO2 is best when the Pt loading is 2wt%.

[0080] Using Pt as the active component yields the highest glycerol conversion rate and glyceric acid / lactic acid selectivity.

[0081] Using Pt as the active component and Cu as an auxiliary agent loaded on SiO2 support, the highest glycerol conversion rate and glyceric acid / lactic acid selectivity can be obtained.

[0082] Using Pt as the active component and Cu as an auxiliary agent loaded on SiO2 support, the highest glycerol conversion rate and glyceric acid / lactic acid selectivity can be obtained.

[0083] In summary, the Pt-Cu / SiO2 catalyst exhibits high glycerol conversion and high selectivity for glyceric acid / lactic acid during glycerol oxidation.

[0084] Test Example 2

[0085] 0.2 g of the Pt-Cu / SiO2 catalyst prepared in Example 2 and 25 mL of 0.1 mol / L glycerol aqueous solution were added to a 25 mL high-pressure reactor, and the reactor was purged with 0.5 MPa of oxygen for reaction. The reaction temperature was 80 °C, the stirring rate was 1000 r / min, and the reaction time was 9 h. After the reaction, the reaction solution was filtered using a disposable syringe and a syringe filter, and the filtrate was subjected to chromatographic analysis. The recovered catalyst was washed with deionized water and ethanol, dried at 70 °C for 5 h, and then the reaction was repeated. The glycerol conversion rate, glyceric acid selectivity, and lactic acid selectivity were calculated, and the cyclic performance of the catalyst was tested. The results are shown in Table 2.

[0086] Table 2 Results of catalyst cyclic performance testing for glycerol oxidation

[0087]

[0088] Test Example 3

[0089] The Pt-Cu / SiO2 catalyst prepared in Example 2 was applied to the oxidation of ethylene glycol to glycolic acid to test the catalyst's stability, hydrothermal resistance, and acid resistance. The steps are as follows:

[0090] 0.2 g of Pt-Cu / SiO2 catalyst and 25 mL of 0.1 mol / L ethylene glycol aqueous solution were added to a 25 mL high-pressure reactor, and oxygen was introduced at 1 MPa for reaction. The reaction temperature was 70 °C, the stirring rate was 1000 r / min, and the reaction time was 6 h. After the reaction, the reaction solution was filtered using a disposable syringe and a syringe filter. The filtrate was subjected to chromatographic analysis. The recovered catalyst was washed with deionized water and ethanol, dried at 70 °C for 5 h, and the reaction performance was tested again without any treatment. The operation was repeated multiple times, and the results are shown in Table 3.

[0091] Table 3. Results of catalyst catalytic cyclic performance testing for ethylene glycol oxidation.

[0092]

[0093] In the above experiments, the reaction products were acidic, and the pH of the reaction system was 1.5-2.6.

[0094] As shown in Table 3, in the reaction of ethylene glycol oxidation to prepare glycolic acid, the conversion rate of ethylene glycol remains high after five rounds of reaction, and the selectivity of glycolic acid decreases by no more than 3%. This indicates that the Pt-Cu / SiO2 catalyst of the present invention has excellent chemical stability.

[0095] The reaction products of Test Example 1 and Test Example 2 were acidic. Each catalytic reaction was carried out in an acidic aqueous medium. After the catalyst stability test, the performance of the catalyst was still maintained at a high level, indicating that the catalyst has good hydrothermal and acid resistance.

[0096] Comparative Example 1

[0097] The difference from Example 2 is that the carrier was not modified.

[0098] The cycle performance of the catalyst was tested using the same methods as in Test Example 2 and Test Example 3. The results are shown in Tables 4 and 5.

[0099] Table 4 Results of catalyst catalytic glycerol oxidation cycle performance test

[0100]

[0101] Table 5. Results of catalyst catalytic cyclic performance testing for ethylene glycol oxidation.

[0102]

[0103] Comparative Example 2

[0104] The difference from Example 2 is that the silane coupling agent KH550 is replaced with an equal amount of silane coupling agent KH590.

[0105] The cycle performance of the catalyst was tested using the same methods as in Test Example 2 and Test Example 3. The results are shown in Tables 6 and 7.

[0106] Table 6 Results of catalyst catalytic glycerol oxidation cycle performance testing

[0107]

[0108]

[0109] Table 7 Results of the catalyst's catalytic performance in the ethylene glycol oxidation cycle.

[0110]

[0111] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

Claims

1. A hydrothermally and acid resistant catalyst for efficient catalysis of polyol oxidation, characterized by, The catalyst comprises a main active component, an auxiliary agent and a modified carrier; The main active component is at least one of Au, Pt and Pd; The auxiliary agent is Cu; The modified carrier is obtained by modifying a carrier; the carrier is at least one of SiO2, Al2O3, TS-1 molecular sieve, ZSM-5 molecular sieve and activated carbon; The preparation method of the modified carrier is as follows: mixing a modifier with the carrier, drying, calcining to obtain the modified carrier; The modifier is a silane coupling agent, the mass ratio of the modifier to the carrier is 1:10, the drying temperature is 70-100℃, the drying time is 5-10 h; the calcining temperature is 500℃, and the calcining time is 4-6 h.

2. The method of claim 1 for the preparation of a hydrothermally and acid resistant catalyst for the efficient catalysis of polyol oxidation, characterized in that, The preparation method is impregnation reduction or solvent reduction.

3. The preparation method according to claim 2, characterized in that, The impregnation reduction method comprises the following steps: After the modified carrier is dried, a main active component precursor solution and an auxiliary agent metal salt solution are added dropwise, stirred uniformly, aged and dried to obtain powder A; After powder A is calcined and reduced in a hydrogen atmosphere, it is cooled, ground and obtained as a high-efficiency catalytic polyol oxidation resistant hydrothermal and acid-resistant catalyst.

4. The production method according to claim 2, characterized by, The solvent reduction method comprises the following steps: The modified carrier is mixed with a solvent to obtain suspension A; The main active component precursor solution and the auxiliary agent metal salt solution are added into suspension A, stirred uniformly to obtain mixture B; Sodium borohydride solution is added dropwise into mixture B, and after reaction, it is aged, filtered and dried to obtain a high-efficiency catalytic polyol oxidation resistant hydrothermal and acid-resistant catalyst.

5. Use of a hydrothermally and acid resistant catalyst which efficiently catalyzes oxidation of a polyol in a polyol catalytic oxidation reaction, characterized by, The high-efficiency catalytic polyol oxidation resistant hydrothermal and acid-resistant catalyst is the high-efficiency catalytic polyol oxidation resistant hydrothermal and acid-resistant catalyst of claim 1 or the high-efficiency catalytic polyol oxidation resistant hydrothermal and acid-resistant catalyst prepared by the method of any one of claims 2-4.

6. Use according to claim 5, characterized in that, The polyol catalytic oxidation reaction is carried out in water as a solvent, air or O2 as an oxidant and under strong stirring.

7. Use according to claim 5, characterized in that, The reaction temperature is 50-200℃, the reaction pressure is normal pressure to 5 MPa, and the reaction time is 1-24 h.

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