A double-layer core-shell type catalyst and its application in propylene aldehyde hydration hydrogenation

Abstract

The present application relates to a kind of double-layer core-shell catalyst, recorded as heteropoly acid nickel phosphide carrier, comprising: innermost layer carrier, intermediate layer nickel phosphide as hydrogenation active component supported on the carrier and outermost layer heteropoly acid as hydration active component.The heteropoly acid nickel phosphide carrier catalyst prepared is loaded in a reactor, and the catalytic hydration hydrogenation of propyl aldehyde is prepared 1,3-propylene glycol, by controlling the hydration of propyl aldehyde and the hydrogenation of 3-hydroxypropionaldehyde sequentially, improve reaction efficiency, avoid polymerization, improve the selectivity of target product.The reaction process is simple and controllable, easy to operate, and has wide application prospect.

Description

Technical Field

[0001] This invention relates to a catalytic method for the hydrogenation of acrolein hydration, specifically a method for the catalytic hydrogenation of acrolein hydration using a core-shell catalyst. Background Technology

[0002] 1,3-Propanediol (1,3-PDO) is an important raw material for the production of unsaturated polyesters, plasticizers, surfactants, emulsifiers, and demulsifiers. As an important polymer monomer, 1,3-PDO is combined with terephthalic acid (PTA) to synthesize polypropylene terephthalate (PTT) fibers, which have broad market prospects in blending and interweaving with fibers such as wool, silk, cotton, and nylon.

[0003] Degussa GmbH in Germany has successfully developed a method for preparing 1,3-PDO via acrolein, involving two steps: (1) hydration of acrolein to 3-hydroxypropanal (3-HPA), and (2) hydrogenation of 3-HPA to 1,3-PDO. This method has mild process conditions, but produces many byproducts, requiring strict control of operating conditions; the product yield and purity are relatively low, necessitating optimization of the catalytic system and process conditions. Patents CN110386856A and CN112062663A report the application of N-alkyl amino acids and N-heterocyclic carboxylic acids as homogeneous catalysts in the catalytic hydration of acrolein. However, homogeneous catalysts present separation difficulties. Patents CN112204422B and CN113105315A report the continuous catalytic hydration of acrolein to 3-hydroxypropanal using cation exchange resins and chelating ion exchange resins. However, Tang Yong mentioned in his research on "New Technology Development for the Preparation of 1,3-Propanediol by Hydrogenation of Acrolein" that the stability of aminocarboxylic acid resin catalysts is difficult to control during long-term operation. The catalysts for the hydrogenation of 3-hydroxypropanal are mainly Raney nickel, supported Ni, and noble metals such as Pt and Pd (CN114011432A, CN115141083A, CN105709778A, CN112264038A). Hydration and hydrogenation are carried out in two separate units, requiring the development of a two-stage catalyst and reaction process, resulting in a long reaction flow and complex operation.

[0004] This invention develops a novel method for preparing acrolein hydration hydrogenation catalysts. A multilayer core-shell catalytic material (heteropolyacid@nickel phosphide@support) is designed and synthesized. This material catalyzes the acrolein hydration hydrogenation reaction to prepare 1,3-PDO in a single-stage reactor. By controlling the sequential occurrence of acrolein hydration and 3-HPA hydrogenation, reaction efficiency can be improved, polymerization reactions can be avoided, and the selectivity of the target product 1,3-PDO can be enhanced. This method is simple to operate and can be applied to the field of acid-metal bifunctional catalysis, such as acrolein hydration hydrogenation. Summary of the Invention

[0005] The problem to be solved by the present invention is to provide a method for preparing a bilayer core-shell catalyst. The catalyst prepared by the invention catalyzes the hydrogenation of acrolein hydration in a single reactor to prepare 1,3-PDO. The method is simple to operate, can improve reaction efficiency, avoid polymerization reaction, and improve the selectivity of the target product 1,3-PDO. It can be applied to the field of acid-metal bifunctional catalysis such as hydrogenation of acrolein hydration and has broad application prospects.

[0006] The technical solution is as follows:

[0007] The bilayer core-shell catalyst of the present invention, denoted as heteropolyacid@nickel phosphide@support, includes an innermost support, an intermediate nickel phosphide layer supported on the support as a hydrogenation active component, and an outermost heteropolyacid layer as a hydration active component.

[0008] The support is an oxide and / or a molecular sieve; the oxide includes one or more of SiO2, γ-Al2O3, TiO2, ZrO2, and amorphous aluminum silicate; the molecular sieve includes any one or more of HZSM-5, Hβ, HY, MCM-41, and SBA-15.

[0009] Intermediate nickel phosphide includes Ni3P, Ni 12 Any one or more of P5 and Ni2P; the loading of nickel phosphide is 5-50 wt% based on nickel phosphide@support;

[0010] The synthesis steps of nickel phosphide@support are as follows:

[0011] Prepare a precursor salt solution containing a nickel source and a phosphorus source. The nickel source is selected from nickel nitrate, nickel chloride, nickel sulfate and / or nickel acetate, and the phosphorus source is selected from diammonium hydrogen phosphate, phosphorous acid and / or sodium hypophosphite.

[0012] The mixed solution was impregnated onto the carrier by impregnation, aged at room temperature for 8-16 hours, dried at 110-130℃ for 6-12 hours, calcined at 400-650℃ for 2-8 hours, and reduced in hydrogen at 400-700℃ for 2-8 hours to obtain nickel phosphide@carrier.

[0013] The outermost heteropoly acid is any one or a combination of two or more of silicotungstic acid, silicotungstic acid, phosphotungstic acid and / or phosphotungstic acid; the loading of heteropoly acid is 5-50 wt% based on the total weight of the catalyst.

[0014] The synthesis steps of heteropolyacid@nickel phosphide@support are as follows:

[0015] Prepare heteropolyacid solutions selected from silicotungstic acid, silicotungstic acid, phosphotungstic acid, and / or phosphotungstic acid;

[0016] The mixture was impregnated onto the carrier by an impregnation method, aged at room temperature for 8-16 hours, dried at 110-130℃ for 6-12 hours, and calcined at 200-400℃ for 2-8 hours to obtain heteropolyacid@nickel phosphide@carrier.

[0017] Application of a double-core-shell catalyst in the hydrogenation reaction of acrolein hydration.

[0018] A fixed-bed reactor was used, with acrolein aqueous solution at a concentration of 10-30 wt% as the feedstock. Hydroquinone was added to the aqueous solution as a polymerization inhibitor at a dosage of 1000-2000 ppm. The reaction temperature was 50-150℃, the reaction pressure was 0.5-5.0 MPa, and the mass hourly space velocity (WHSV) of the acrolein aqueous solution was 0.1-2.0 h⁻¹. -1 .

[0019] Beneficial technical effects

[0020] 1. This invention prepares a bilayer core-shell heteropolyacid@nickel phosphide@supported catalyst to catalyze the hydrogenation of acrolein hydration to 1,3-propanediol in a single-stage reactor. By controlling the sequential hydration of acrolein and the hydrogenation of 3-hydroxypropane, the reaction efficiency is improved, polymerization reaction is avoided, and the selectivity of the target product is enhanced.

[0021] 2. Catalysts have advantages such as high reactivity and good stability. The reaction process is simple, controllable and easy to operate, and has broad application prospects. Detailed Implementation

[0022] To provide a more detailed description of the present invention, several specific implementation examples are given below, but the present invention is not limited to these embodiments.

[0023] Example 1

[0024] (1) Weigh 3g of SiO2 support and add it to a mixed aqueous solution containing 4.21g of Ni(NO3)2·6H2O and 0.64g of (NH4)2HPO4. Let it stand at room temperature for 12h, dry the material at 120℃ for 10h, calcine at 500℃ for 4h, and reduce it at 500℃ for 3h in H2 atmosphere (flow rate 50mL / min) to obtain Ni3P@SiO2 precursor. The loading of Ni3P is 25% based on the weight of Ni3P@SiO2.

[0025] (2) The Ni3P@SiO2 precursor obtained in step (1) is added to a mixture containing 1.33g H4SiW 12 O 40The material was aged and allowed to stand at room temperature for 12 hours in an aqueous solution. The resulting material was then dried at 120°C for 12 hours and calcined at 250°C for 3 hours to obtain the SiW@Ni3P@SiO2 catalyst, designated as catalyst 1. The SiW content was 25 wt% by weight. Characterization by XRD and transmission electron microscopy revealed that the catalyst was a bilayer core-shell catalyst. The innermost layer consisted of support particles, the middle layer was nickel phosphide supported on the support, and the outermost layer was a heteropolyacid layer encapsulating the nickel phosphide middle layer, designated as heteropolyacid@nickel phosphide@support.

[0026] (3) Catalyst evaluation: The reaction was carried out in a fixed-bed tubular reactor. The feedstock was a 20 wt% aqueous solution of acrolein, containing 1500 ppm of hydroquinone as a polymerization inhibitor. The reaction temperature was 100 °C, the H2 pressure was 2.0 MPa, and the mass hourly space velocity was 1.0 h⁻¹. -1 After gas-liquid separation, the product was analyzed by gas chromatography to determine its composition and content, and the conversion rate of acrolein and the selectivity of 1,3-propanediol were calculated.

[0027] Example 2

[0028] Compared with Example 1, the difference is that in step (1), an Al2O3 support was selected, and the mixed aqueous solution contained 3.92g Ni(NO3)2·6H2O and 0.89g (NH4)2HPO4, while the rest was exactly the same as in Example 1; a SiW@Ni2P@Al2O3 catalyst was prepared and designated as catalyst 2. The catalyst evaluation conditions and process were the same as in Example 1.

[0029] Example 3

[0030] Compared with Example 1, the difference is that in step (1), a TiO2 support was selected, and the mixed aqueous solution contained 3.81g NiSO4·6H2O and 0.64g (NH4)2HPO4, while the rest was exactly the same as in Example 1; a SiW@Ni3P@TiO2 catalyst was prepared and designated as catalyst 3. The catalyst evaluation conditions and process were the same as in Example 1.

[0031] Example 4

[0032] Compared with Example 1, the difference is that in step (1), a ZrO2 support was selected, and the mixed aqueous solution contained 3.44g NiCl2·6H2O and 0.51g NaH2PO2·H2O, while the rest was exactly the same as in Example 1; a SiW@Ni3P@ZrO2 catalyst was prepared and designated as catalyst 4. The catalyst evaluation conditions and process were the same as in Example 1.

[0033] Example 5

[0034] Compared with Example 1, the difference is that in step (1), an amorphous silica-alumina support was selected, and the mixed aqueous solution contained 3.61g Ni(CH3COO)2·4H2O and 0.4g H3PO3, while the rest was exactly the same as in Example 1; a SiW@Ni3P@ amorphous silica-alumina catalyst was prepared and designated as catalyst 5. The catalyst evaluation conditions and process were the same as in Example 1.

[0035] Example 6

[0036] Compared with Example 1, the difference is that in step (1), HZSM-5 support was selected, and the mixed aqueous solution contained 3.44g Ni(NO3)2·6H2O and 0.64g (NH4)2HPO4, while the rest was exactly the same as in Example 1; the SiW@Ni3P@HZSM-5 catalyst was prepared and designated as catalyst 6. The catalyst evaluation conditions and process were the same as in Example 1.

[0037] Example 7

[0038] Compared with Example 1, the difference is that in step (1), HY support was selected, and the mixed aqueous solution contained 3.92g Ni(NO3)2·6H2O and 0.89g (NH4)2HPO4, while the rest was exactly the same as in Example 1; the SiW@Ni2P@HY catalyst was prepared and designated as catalyst 7. The catalyst evaluation conditions and process were the same as in Example 1.

[0039] Example 8

[0040] Compared with Example 1, the difference is that in step (1), Hβ support was selected, and the mixed aqueous solution contained 4.21g Ni(NO3)2·6H2O and 0.71g NaH2PO2·H2O, while the rest was exactly the same as in Example 1; the SiW@Ni3P@Hβ catalyst was prepared and designated as catalyst 8. The catalyst evaluation conditions and process were the same as in Example 1.

[0041] Example 9

[0042] Compared with Example 1, the difference is that in step (1), MCM-41 support was selected, and the mixed aqueous solution contained 4.06g Ni(NO3)2·6H2O and 0.77g (NH4)2HPO4, while the rest was exactly the same as in Example 1; SiW@Ni was prepared. 12 The P5@MCM-41 catalyst is designated as catalyst 9. The catalyst evaluation conditions and procedures are the same as in Example 1.

[0043] Example 10

[0044] Compared with Example 1, the difference is that in step (1), SBA-15 support was selected, and the mixed aqueous solution contained 4.21g Ni(NO3)2·6H2O and 0.4g H3PO3, while the rest was exactly the same as in Example 1; the SiW@Ni3P@SBA-15 catalyst was prepared and designated as catalyst 10. The catalyst evaluation conditions and process were the same as in Example 1.

[0045] Example 11: Types of Hydrogenation Active Components

[0046] (1) Weigh 3g of SiO2 support and add it to a mixed aqueous solution containing 3.92g of Ni(NO3)2·6H2O and 0.89g of (NH4)2HPO4. Let it stand at room temperature for 8h. The resulting material is dried at 110℃ for 12h, calcined at 650℃ for 2h, and reduced at 600℃ for 2h in H2 atmosphere (flow rate 50mL / min) to obtain Ni2P@SiO2 precursor. The loading of Ni3P is 25% based on the weight of Ni3P@SiO2.

[0047] (2) The Ni3P@SiO2 precursor obtained in step (1) is added to a mixture containing 1.33g H4SiW 12 O 40 The material was aged and allowed to stand at room temperature for 8 hours in an aqueous solution. The resulting material was dried at 130°C for 6 hours and calcined at 400°C for 2 hours to obtain the SiW@Ni2P@SiO2 catalyst, designated as catalyst 11. The SiW content was 25 wt% by weight of the catalyst.

[0048] (3) Catalyst evaluation: The catalyst evaluation conditions and procedures are the same as in Example 1.

[0049] Example 12: Types of Hydrogenation Active Components

[0050] (1) Weigh 3g of SiO2 support and add it to a mixed aqueous solution containing 4.06g of Ni(NO3)2·6H2O and 0.77g of (NH4)2HPO4. Let it stand at room temperature for 16h, dry the resulting material at 130℃ for 6h, calcine it at 400℃ for 8h, and reduce it at 400℃ for 8h in H2 atmosphere (flow rate 50mL / min) to obtain Ni 12 P5@SiO2 precursor, with Ni 12 By weight of P5@SiO2, the loading of Ni3P is 25%.

[0051] (2) The Ni3P@SiO2 precursor obtained in step (1) is added to a mixture containing 1.33g H4SiW 12 O 40 The material was aged and allowed to stand at room temperature for 16 hours in an aqueous solution, then dried at 110°C for 12 hours and calcined at 200°C for 8 hours to obtain SiW@Ni.12 The P5@SiO2 catalyst, designated as catalyst 12, has a SiW content of 25 wt% by weight.

[0052] (3) Catalyst evaluation: The catalyst evaluation conditions and procedures are the same as in Example 1.

[0053] Example 13: Increased loading of hydrogenated active components

[0054] Compared with Example 1, the difference is that the mixed aqueous solution in step (1) contains 12.64g Ni(NO3)2·6H2O and 1.91g (NH4)2HPO4, and the mixed aqueous solution in step (2) contains 2g H4SiW. 12 O 40 The rest was exactly the same as in Example 1; a SiW@Ni3P@SiO2 catalyst was prepared, designated as catalyst 13, with a Ni3P loading of 50 wt% based on Ni3P@SiO2. The catalyst evaluation conditions and procedures were the same as in Example 1.

[0055] Example 14: Reduced loading of hydrogenated active component

[0056] Compared with Example 1, the difference is that the mixed aqueous solution in step (1) contains 0.67g Ni(NO3)2·6H2O and 0.1g (NH4)2HPO4, and the mixed aqueous solution in step (2) contains 1.05g H4SiW. 12 O 40 The rest was exactly the same as in Example 1; a SiW@Ni3P@SiO2 catalyst was prepared, designated as catalyst 14, with a Ni3P loading of 5 wt% based on Ni3P@SiO2. The catalyst evaluation conditions and procedures were the same as in Example 1.

[0057] Example 15: Types of Hydrated Active Components

[0058] The difference compared to Example 1 is that the mixed aqueous solution in step (2) contains 1.33g of H4SiMo. 12 O 40 The rest was exactly the same as in Example 1; the SiMo@Ni3P@SiO2 catalyst was prepared and designated as catalyst 15. The catalyst evaluation conditions and process were the same as in Example 1.

[0059] Example 16: Types of Hydrated Active Components

[0060] The difference compared to Example 1 is that the mixed aqueous solution in step (2) contains 1.33g of H3PMo. 12 O 40Everything else was exactly the same as in Example 1; the PMo@Ni3P@SiO2 catalyst was prepared and designated as catalyst 16. The catalyst evaluation conditions and process were the same as in Example 1.

[0061] Example 17: Types of Hydrated Active Components

[0062] The difference compared to Example 1 is that the mixed aqueous solution in step (2) contains 1.33g of H3PW. 12 O 40 The rest was exactly the same as in Example 1; a PW@Ni3P@SiO2 catalyst was prepared and designated as catalyst 17. The catalyst evaluation conditions and process were the same as in Example 1.

[0063] Example 18: Increased loading of hydrated active components

[0064] The difference from Example 1 is that the mixed aqueous solution in step (2) contains 4g of H4SiW. 12 O 40 The rest was exactly the same as in Example 1; a SiW@Ni3P@SiO2 catalyst was prepared, designated as catalyst 18, with a SiW loading of 50% based on SiW@Ni3P@SiO2. The catalyst evaluation conditions and process were the same as in Example 1.

[0065] Example 19: Reduced loading of hydrated active components

[0066] The difference from Example 1 is that the mixed aqueous solution in step (2) contains 0.21g H4SiW 12 O 40 The rest was exactly the same as in Example 1; a SiW@Ni3P@SiO2 catalyst was prepared, designated as catalyst 19, with a SiW loading of 5% based on SiW@Ni3P@SiO2. The catalyst evaluation conditions and procedures were the same as in Example 1.

[0067] Example 20: Reaction conditions, raw materials, temperature, pressure, space velocity

[0068] Catalyst 1 was used in a fixed-bed tubular reactor. The feedstock was a 10 wt% aqueous solution of acrolein with a hydroquinone content of 1000 ppm. The reaction temperature was 50 °C, the reaction pressure was 0.5 MPa, and the mass hourly space velocity (WHSV) was 1.0 h⁻¹. -1 Product analysis was the same as in Example 1.

[0069] Example 21: Reaction conditions, raw materials, temperature, pressure, space velocity

[0070] Catalyst 1 was used in a fixed-bed tubular reactor. The feedstock was a 10 wt% aqueous solution of acrolein with a hydroquinone content of 1500 ppm. The reaction temperature was 150 °C, the reaction pressure was 5.0 MPa, and the mass hourly space velocity (WHSV) was 0.1 h⁻¹. -1 Product analysis was the same as in Example 1.

[0071] Example 22: Reaction conditions, raw materials, temperature, pressure, space velocity

[0072] Catalyst 1 was used in a fixed-bed tubular reactor. The feedstock was a 30 wt% aqueous solution of acrolein with a hydroquinone content of 2000 ppm. The reaction temperature was 150 °C, the reaction pressure was 5.0 MPa, and the mass hourly space velocity (WHSV) was 2.0 h⁻¹. -1 Product analysis was the same as in Example 1.

[0073] Table 1 below lists the reaction evaluation results of the catalysts prepared by the method of the present invention.

[0074]

[0075]

[0076] From Examples 1-10, the catalysts using silica as the support, Ni3P as the hydrogenation active center, and SiW as the hydration active center exhibited the highest acrolein conversion and 1,3-propanediol selectivity. From the 1,3-propanediol selectivity in Examples 1 and 11, 12, it is evident that Ni3P showed the highest activity, followed by Ni2P, and Ni... 12 P5 is the lowest; from the conversion rates of acrolein in Examples 1 and 15-17, it can be seen that SiW>PW>SiMo>PMo; from Examples 1 and 13, 14, 18, and 19, it can be seen that the reaction activity gradually increases with the increase of the content of the active component; from Examples 1 and 20-22, it can be seen that the concentration of acrolein, space velocity, amount of hydroquinone added, reaction temperature, and pressure have a significant impact on the catalytic reaction performance.

Claims

1. A double-layered core-shell catalyst, characterized in that, The dual-layer core-shell catalyst comprises: an innermost layer of support particles; an intermediate layer of nickel phosphide loaded on the support as the hydrogenation active component; and an outermost layer of heteropolyacid, which is a hydration active component, surrounding the support loaded with nickel phosphide, denoted as heteropolyacid@nickel phosphide@support; the loading of nickel phosphide is 5-50 wt% based on nickel phosphide@support; the outermost heteropolyacid is any one or a combination of two or more of silicotungstic acid, silicotomolybdic acid, phosphotungstic acid, and / or phosphotomolybdic acid; the loading of heteropolyacid is 5-50 wt% based on the total weight of the catalyst. The intermediate nickel phosphide layer includes Ni3P and Ni 12 Any one or more combinations of P5 and Ni2P.

2. The catalyst according to claim 1, characterized in that: The support is one or more of oxides and / or molecular sieves; the oxide includes one or more of SiO2, γ-Al2O3, TiO2, ZrO2, and amorphous silica-alumina; the molecular sieve includes any one or more of HZSM-5, Hβ, HY, MCM-41, and SBA-15.

3. The catalyst according to claim 1 or 2, characterized in that, The synthesis steps of nickel phosphide@support are as follows: A precursor salt solution containing nickel and phosphorus sources is prepared, impregnated onto a support, and then subjected to aging, drying, calcination, and reduction to obtain the nickel phosphide@support.

4. The catalyst according to claim 3, characterized in that, The nickel source in the precursor salt solution is selected from one or more of nickel nitrate, nickel chloride, nickel sulfate, or nickel acetate; the phosphorus source in the precursor salt solution is selected from one or more of diammonium hydrogen phosphate, phosphorous acid, or sodium hypophosphite; the mixed solution is impregnated onto the carrier by an impregnation method, aged at room temperature for 8-16 h, dried at 110-130 ℃ for 6-12 h, calcined at 400-650 ℃ for 2-8 h, and reduced in hydrogen at 400-700 ℃ for 2-8 h to obtain nickel phosphide@carrier.

5. The catalyst according to claim 1, characterized in that, The synthesis steps of heteropolyacid@nickel phosphide@support are as follows: A heteropoly acid solution was prepared and impregnated onto a nickel phosphide@carrier. After aging, drying, and calcination, the heteropoly acid@nickel phosphide@carrier was obtained.

6. The catalyst according to claim 5, characterized in that, The heteropoly acid raw material is selected from silicotungstic acid, silicotungstic acid, phosphotungstic acid and / or phosphotungstic acid; the heteropoly acid solution is impregnated onto the carrier by impregnation method, aged at room temperature for 8-16 h, dried at 110-130℃ for 6-12 h, and calcined at 200-400℃ for 2-8 h to obtain heteropoly acid@nickel phosphide@carrier.

7. The use of the double-core-shell catalyst according to any one of claims 1-6 in the hydrogenation of acrolein hydration to prepare 1,3-propanediol.

8. The application according to claim 7, characterized in that: A fixed-bed reactor was used. The reactant was an aqueous solution of acrolein with a concentration of 10-30 wt%. Hydroquinone was added to the aqueous solution as a polymerization inhibitor at a dosage of 1000-2000 ppm. The reaction temperature was 50-150 ℃, the reaction pressure was 0.5-5.0 MPa, and the mass hourly space velocity (WHSV) of the acrolein aqueous solution was 0.1-2.0 h⁻¹. -1 .

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