Dual-site single-atom catalyst and preparation method and application thereof

Abstract

The invention discloses a dual-site single-atom catalyst and a preparation method thereof, which specifically comprises: loading metal Cu nanoparticles on a SiO2 carrier by an impregnation method to obtain Cu / SiO2; adding Cu / SiO2 to a metal oxide precursor solution, stirring and reacting under the protection of an inert gas, filtering, drying, and heat-treating to obtain a catalyst M1O x / Cu / SiO2; M1O x / Cu / SiO2 is added to the noble metal precursor solution, stirred and reacted under the protection of inert gas, filtered, dried, and heat treated to obtain M1O x ‑M'1 / Cu / SiO2, that is, a dual-site single-atom catalyst. The dual-site single-atom catalyst of the present invention can be used in the selective hydrogenolysis reaction of the C‑O bond of biomass polyols, which can greatly reduce the hydrogen pressure in the reaction and has high selectivity and good stability.

Description

Technical Field

[0001] The invention belongs to the technical field of catalyst synthesis and application, and specifically relates to a double-site single-atom catalyst, and also relates to a preparation method and application of the catalyst. Background Art

[0002] Biomass is a renewable organic carbon source. Using biomass as raw material to produce liquid fuels and chemicals is one of the important ways to achieve green chemistry. The selective hydrogenolysis of CO bonds in biomass polyols is one of the important reactions, and the design of multifunctional catalysts is the key to achieving the selective hydrogenolysis of CO bonds in biomass polyols.

[0003] 1,6-Hexanediol is an important fine chemical raw material, which is widely used in the synthesis of fine chemicals such as polyester, polyurethane, coating, medicine, pesticide, etc. At present, the industrial synthesis methods of 1,6-hexanediol are mainly as follows: (1) 1,6-hexanediol is prepared from 1,6-hexanediol by using supported ruthenium and rhodium catalysts, the catalyst carrier is alumina, and 1,6-hexanediol is continuously prepared from adipic acid in a fixed bed reactor (Chinese patent CN110963887A); (2) 1,6-hexanediol is prepared from bio-based furan compounds by using bio-based furan compounds such as 5-hydroxymethylfurfural and 2,5-furan. (3) Preparation of 1,6-hexanediol from cyclohexene: using cyclohexene as raw material, through oxidation and hydrogenation, first oxidizing cyclohexene to adipic aldehyde, and then hydrogenating the adipic aldehyde to generate 1,6-hexanediol product (Chinese patent CN113860989A).

[0004] In summary, the current methods for preparing terminal diols mostly rely on non-renewable fossil resources, mainly using petroleum as raw materials, and have the disadvantages of long production process and large amount of waste discharged during the production process. Therefore, it is urgent to develop a new renewable green and environmentally friendly path to prepare terminal diols to achieve high-value utilization of renewable resources and environmental protection. Summary of the invention

[0005] The object of the present invention is to provide a dual-site single-atom catalyst, which improves the catalytic activity of the single-atom catalyst through the synergistic effect of the noble metal alloy single-atom site and the single-atom dispersed metal oxide site.

[0006] The second object of the present invention is to provide a method for preparing a dual-site single-atom catalyst.

[0007] The third objective of the present invention is to provide the use of the above-mentioned dual-site single-atom catalyst in the selective hydrogenolysis reaction of CO bonds of biomass polyols.

[0008] The technical solution adopted by the present invention is that a dual-site single-atom catalyst is formed by loading metal Cu nanoparticles on a SiO2 carrier, and then constructing a noble metal alloy single-atom component and a monodisperse metal oxide component on the surface of the metal Cu nanoparticles to form a dual-site single-atom active component.

[0009] The present invention is also characterized in that:

[0010] The single atomic component of the precious metal alloy is any one of Pt, Pd, Rh, Ru, Ir, and Ag; the monodisperse metal oxide component is any one of Mo, W, Re, Ta, and Nb.

[0011] The technical solution adopted by the present invention is a method for preparing a dual-site single-atom catalyst, which is specifically implemented according to the following steps:

[0012] Step 1, using an impregnation method to load metal Cu nanoparticles on a SiO2 carrier to prepare Cu / SiO2;

[0013] Step 2, dissolving the metal oxide precursor in a solvent to obtain a metal oxide precursor solution, adding Cu / SiO2 to the metal oxide precursor solution, stirring and reacting under the protection of an inert gas, filtering after the reaction, drying, and heat treating to obtain a catalyst M1O x / Cu / SiO2;

[0014] Step 3, dissolving the noble metal precursor in a solvent to obtain a noble metal precursor solution, and mixing M1O x / Cu / SiO2 is added to the noble metal precursor solution, stirred under the protection of inert gas, and filtered, dried, and heat-treated after the reaction is completed to obtain M1O x -M'1 / Cu / SiO2, that is, a dual-site single-atom catalyst.

[0015] The present invention is also characterized in that:

[0016] In step 1, specifically: dissolve and disperse the copper compound in a solvent to obtain a Cu precursor solution, immerse the SiO2 carrier in the Cu precursor solution for 4-20 hours, dry it at 40-100°C for 4-10 hours, and treat it at 350-550°C in a hydrogen or nitrogen or a mixed atmosphere of the two for 0.5-5 hours to obtain Cu / SiO2.

[0017] In step 2, the reaction temperature is 20-100° C., and the reaction time is 0.5-6 h; the drying temperature is 40-100° C., and the drying time is 4-10 h.

[0018] In step 2, the metal is any one of Mo, W, Re, Ta, and Nb.

[0019] In steps 2 and 3, the heat treatment is: treating at 200-500° C. for 0.5-5 h in a hydrogen or nitrogen or a mixed atmosphere of the two.

[0020] In step 3, the reaction temperature is 20-100° C., and the reaction time is 0.5-6 h; the drying temperature is 40-100° C., and the drying time is 4-10 h.

[0021] In step 3, the noble metal is any one of Pt, Pd, Rh, Ru, Ir, and Ag.

[0022] The beneficial effects of the present invention are:

[0023] The catalyst prepared by the present invention has a noble metal alloy single-atom hydrogenation site, a fast and long-distance hydrogen overflow metal Cu surface, and a monodisperse metal oxide site. The three act synergistically to achieve high catalytic performance for preparing 1,6-hexanediol by selective hydrogenolysis of the CO bond of tetrahydrofuran dimethanol. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is an electron microscope image of the 0.2Pt / 2Cu / SiO2 sample of the present invention (I);

[0025] Figure 2 This is the electron microscope image (II) of the 0.2Pt / 2Cu / SiO2 sample of the present invention;

[0026] Figure 3 This is the electron microscope image (III) of the 0.2Pt / 2Cu / SiO2 sample of the present invention;

[0027] Figure 4 It is the energy spectrum diagram of the 0.2Pt / 2Cu / SiO2 sample of the present invention;

[0028] Figure 5 It is the 0.1Mo1O x -0.2Pt / 2Cu / SiO2 catalyst cyclic stability test diagram. DETAILED DESCRIPTION

[0029] The present invention will be further described below through the accompanying drawings and specific embodiments.

[0030] The dual-site single-atom catalyst of the present invention uses SiO2 as a carrier, loads metal Cu nanoparticles, and constructs a noble metal alloy single-atom component M'1 (M'=Pt, Pd, Rh, Ru, Ir, Ag) and a monodisperse metal oxide component M1O on the surface of the metal Cu. x (M=Mo, W, Re, Ta, Nb), forming a dual-site single-atom active component.

[0031] The preparation method of the dual-site single-atom catalyst of the present invention is specifically implemented according to the following steps:

[0032] Step 1, using SiO2 as a carrier, and loading metal Cu nanoparticles on the SiO2 carrier by an impregnation method;

[0033] Specifically, the copper compound is dissolved and dispersed in a solvent to obtain a Cu precursor solution, the SiO2 carrier is immersed in the Cu precursor solution for 4-20 hours, dried at 40-100°C for 4-10 hours, and treated at 350-550°C in a hydrogen or nitrogen or a mixed atmosphere of the two for 0.5-5 hours to obtain Cu / SiO2;

[0034] The loading amount of Cu is 1-20wt% (preferably 2-10wt%); the impregnation method is equal volume impregnation or excess impregnation.

[0035] The Cu compound is selected from any one of (Cu(NO3)2·3H2O, Cu(CH3COO)2·H2O, Na2CuEDTA, (NH4)2CuEDTA.

[0036] Step 2, dissolving a metal oxide precursor in a solvent to obtain a metal oxide precursor solution, adding Cu / SiO2 to the metal oxide precursor solution, stirring and reacting under the protection of an inert gas, the reaction temperature is 20°C-100°C, the time is 0.5-6h, filtering after the reaction is completed, drying at 40-100°C for 4-10h, and treating at 200-500°C for 0.5-5h under a hydrogen or nitrogen or a mixed atmosphere of the two, to obtain a catalyst M1O x / Cu / SiO2 (M=Mo, W, Re, Ta, Nb); its theoretical loading amount is 0.05-4wt% (preferably 0.05-1wt%).

[0037] The metal is any one of Mo, W, Re, Ta, and Nb;

[0038] Step 3, dissolving the noble metal precursor in a solvent to obtain a noble metal precursor solution, and mixing M1O x / Cu / SiO2 is added to the noble metal precursor solution, stirred and reacted under the protection of inert gas, the reaction temperature is 20-100℃, and the time is 0.5-6h. After the reaction is completed, it is filtered, dried at 40-100℃ for 4-10h, and treated at 200-500℃ for 0.5-5h in hydrogen or nitrogen or a mixed atmosphere of the two. The obtained sample is M1O x -M'1 / Cu / SiO2 (M'=Pt, Pd, Rh, Ru, Ir, Ag), i.e. a dual-site single-atom catalyst; its theoretical loading is 0.05-2wt% (preferably 0.05-1wt%);

[0039] The noble metal is any one of Pt, Pd, Rh, Ru, Ir and Ag;

[0040] The precursor of the precious metal is one of its soluble metal chlorate, nitrate, and organic matter; the precursor of the metal oxide is one of its soluble metal chlorate, nitrate, and organic matter; the drying method is any one of conventional drying, vacuum drying, and freeze drying;

[0041] The double-site single-atom catalyst prepared by the method of the present invention is applied to the selective hydrogenolysis reaction of CO bonds of biomass polyols, that is, the selective hydrogenolysis of CO bonds of tetrahydrofuran dimethanol to prepare 1,6-hexanediol. The reaction conditions are as follows: the reaction is carried out in an intermittent reactor, the concentration range of tetrahydrofuran dimethanol is 1-99.9%, the hydrogen pressure is 1-10MPa, the reaction temperature is 100-300°C, and the reaction time is 4-48h. The amount of catalyst is 0.05-0.5g; the mass concentration range of tetrahydrofuran dimethanol is preferably 1-30%, the hydrogen pressure is preferably 0.1-5MPa, the reaction temperature is preferably 120-160°C, and the reaction time is preferably 12-24h.

[0042] The catalyst prepared by the present invention can realize the selective and precise construction of double-site single atoms on the surface of metal Cu, and the coordination environment and electronic structure of the active site are adjustable. It can also greatly reduce the hydrogen pressure during the reaction process, so that the tetrahydrofuran dimethanol solution can be highly selectively hydrogenated to generate 1,6-hexanediol under low pressure, and the catalyst has good stability.

[0043] Example 1 Preparation of Cu / SiO2

[0044] 0.1 g Cu(CH3COO)2·H2O was dissolved in anhydrous ethanol to prepare a precursor solution. 1.8 g SiO2 carrier was immersed in the Cu precursor solution for 10 h, dried at 50°C for 6 h, and reduced at 400°C for 1 h in a hydrogen atmosphere to obtain 2Cu / SiO2 with a theoretical Cu loading of 2 wt%.

[0045] Same as above, other conditions remain unchanged, the SiO2 carrier is immersed in different amounts of copper precursor solution to obtain Cu / SiO2 with different loading amounts (the theoretical loading amount of Cu is 2-10wt%).

[0046] Example 2 Monodisperse metal oxide catalyst M1O x Preparation of / Cu / SiO2

[0047] 0.1Mo1O x0.1Mo1O2 / 2Cu / SiO2 was prepared as an example: 0.012g of ammonium molybdate was weighed, and the ammonium molybdate solution was used as a precursor. Mo was dispersed on the surface of the metal Cu nanoparticles prepared in Example 1 by a surface reaction method. Cu / SiO2 was added to the precursor solution of Mo, and stirred to react under nitrogen protection. The reaction temperature was 60°C and the reaction time was 2h. After the reaction was completed, it was filtered, dried at 50°C for 6h, and reduced at 300°C for 1h under a hydrogen atmosphere to obtain a catalyst 0.1Mo1O2 / 2Cu / SiO2. x / 2Cu / SiO2.

[0048] Same as above, other conditions remain unchanged, Cu / SiO2 is added to different amounts of Mo precursor solution to prepare catalyst 1Mo1O x / 2Cu / SiO2、0.6Mo1O x / 2Cu / SiO2、0.3Mo1O x / 2Cu / SiO2、0.1Mo1O x / 2Cu / SiO2、0.05Mo1O x / 2Cu / SiO2.

[0049] Same as above, other conditions remain unchanged, Cu / SiO2 is added to different metal oxide precursor solutions to prepare catalyst W1O x / 2Cu / SiO2、Re1O x / 2Cu / SiO2、Ta1O x / 2Cu / SiO2、Nb1O x / 2Cu / SiO2.

[0050] Example 3 Preparation of Noble Metal Alloy Single Atom Catalyst M'1 / Cu / SiO2

[0051] Take the preparation method of 0.2Pt / 2Cu / SiO2 as an example: weigh 0.024g of platinum acetylacetonate, use platinum acetylacetonate solution as a precursor, and disperse Pt on the surface of the metal Cu nanoparticles prepared in Example 1 by a surface reaction method. Add Cu / SiO2 to the precursor solution of Pt, stir and react under nitrogen protection, the reaction temperature is 60°C, the reaction time is 2h, filter after the reaction, dry at 50°C for 6h, and reduce at 300°C for 1h under a hydrogen atmosphere to obtain the catalyst 0.2Pt / 2Cu / SiO2.

[0052] Same as above, other conditions remain unchanged, Cu / SiO2 is added to the precursor solution of different amounts of Pt to prepare catalysts 0.05Pt / 2Cu / SiO2, 0.2Pt / 2Cu / SiO2, 0.6Pt / 2Cu / SiO2, and 1Pt / 2Cu / SiO2.

[0053] Figure 1-Figure 4The electron microscope and energy spectrum of the 0.2Pt / 2Cu / SiO2 sample show that the precious metal Pt is mainly selectively dispersed on the surface of Cu nanoparticles, and is most likely dispersed at the atomic level.

[0054] As above, other conditions remain unchanged, and Cu / SiO2 is added to different types of precious metal precursor solutions to prepare catalysts Pd / 2Cu / SiO2, Rh / 2Cu / SiO2, Ru / 2Cu / SiO2, Ir / 2Cu / SiO2, and Ag / 2Cu / SiO2.

[0055] Example 4 Dual-site single-atom catalyst Mo1O x - Preparation of 0.2Pt / 2Cu / SiO2

[0056] 0.1Mo1O x Taking the preparation method of -0.2Pt / 2Cu / SiO2 as an example: 0.012g of ammonium molybdate was weighed, and ammonium molybdate solution was used as a precursor. 0.2Pt / 2Cu / SiO2 was added to the precursor solution of Mo, and stirred under nitrogen protection. The reaction temperature was 60°C and the reaction time was 2h. After the reaction was completed, it was filtered, dried at 50°C for 6h, and reduced at 300°C for 1h in a hydrogen atmosphere to obtain the catalyst 0.1Mo1O x -0.2Pt / 2Cu / SiO2.

[0057] As above, other conditions remain unchanged, 0.2Pt / 2Cu / SiO2 is added to the precursor solution of different amounts of Mo to prepare the catalyst 1Mo1O x -0.2Pt / 2Cu / SiO2, 0.6Mo1O x -0.2Pt / 2Cu / SiO2, 0.3Mo1O x -0.2Pt / 2Cu / SiO2, 0.1Mo1O x -0.2Pt / 2Cu / SiO2, 0.05Mo1O x -0.2Pt / 2Cu / SiO2.

[0058] Example 5 Dual-site single-atom catalyst 0.1Mo1O x -Preparation of Pt / 2Cu / SiO2

[0059] 0.1Mo1O x -0.2Pt / 2Cu / SiO2 preparation method: weigh 0.024g of platinum acetylacetonate, use platinum acetylacetonate solution as a precursor, and mix 0.1Mo1O x / 2Cu / SiO2 was added to the precursor solution of Pt, stirred and reacted under nitrogen protection, the reaction temperature was 60℃, the reaction time was 2h, filtered after the reaction was completed, dried at 50℃ for 6h, and reduced at 300℃ for 1h under hydrogen atmosphere to obtain 0.1Mo1O x -0.2Pt / 2Cu / SiO2.

[0060] Same as above, other conditions remain unchanged, 0.1Mo1O x / 2Cu / SiO2 was added into the precursor solution with different amounts of Pt to obtain the catalyst 0.1Mo1O x -0.05Pt / 2Cu / SiO2, 0.1Mo1O x -0.2Pt / 2Cu / SiO2, 0.1Mo1O x -0.6Pt / 2Cu / SiO2, 0.1Mo1O x -1Pt / 2Cu / SiO2.

[0061] Example 6 Dual-site single-atom catalyst 0.1M1O x - Preparation of 0.2Pt / 2Cu / SiO2

[0062] As in Example 4, 0.2Pt / 2Cu / SiO2 was added to different types of metal oxide precursor solutions to prepare catalyst 0.1M1O x -0.2Pt / 2Cu / SiO2 (M=Mo, W, Re, Ta, Nb, etc.).

[0063] Example 7 Dual-site single-atom catalyst 0.1Mo1O x -Preparation of 0.2M'1 / 2Cu / SiO2

[0064] As in Example 5, 0.1Mo1O x / 2Cu / SiO2 was added into different kinds of precious metal precursor solutions to prepare the catalyst 0.1Mo1O x -0.2M'1 / 2Cu / SiO2 (M'=Pt, Pd, Rh, Ru, Ir, Ag, etc.).

[0065] Catalyst performance test

[0066] A batch reactor was selected, the mass concentration of tetrahydrofuran dimethanol aqueous solution was 5% (a total of 8 g of the solution), the amount of catalyst was 0.3 g, the reaction temperature was 140° C., the reaction pressure was 1 MPa, and the reaction time was 12 h.

[0067] Catalyst stability test

[0068] A batch reactor was selected, the mass concentration of tetrahydrofuran dimethanol aqueous solution was 5% (a total of 8 g of solution), the amount of catalyst was 0.3 g, the reaction temperature was 140°C, the reaction pressure was 1 MPa, the reaction time was 12 h, and the cyclic stability of the catalyst was tested. The test results are as follows Figure 2 As shown; it can be seen from the figure that 0.1Mo1O x -0.2Pt / 2Cu / SiO2 catalyst has good stability in the conversion process of tetrahydrofuran dimethanol to 1,6-hexanediol, and there is no deactivation of the catalyst after 7 cycles.

[0069] The effects of different metal oxide single atom loadings on the catalyst are shown in Table 1. The reaction conditions are the same as those for the catalyst performance test.

[0070] Table 1 Effect of different metal oxide single atom loading on catalyst

[0071] catalyst Conversion rate (%) Selectivity (%) 1,6-Hexanediol yield (%) <![CDATA[1Mo1O x / 2Cu / SiO2]]> 8.2 17.5 1.4 <![CDATA[0.6Mo1O x / 2Cu / SiO2]]> 9.3 19.8 1.8 <![CDATA[0.3Mo1O x / 2Cu / SiO2]]> 10.5 15.9 1.7 <![CDATA[0.1Mo1O x / 2Cu / SiO2]]> 15.8 13.6 2.1 <![CDATA[0.05Mo1O x / 2Cu / SiO2]]> 11.2 10.7 1.2

[0072] It can be seen from Table 1 that 0.1Mo1O x / 2Cu / SiO2 has the best conversion rate and selectivity.

[0073] The effects of different noble metal single atom loadings on the catalyst are shown in Table 2. The reaction conditions are the same as those for the catalyst performance test.

[0074] Table 2 Effect of different noble metal single atom loadings on catalysts

[0075] catalyst Conversion rate (%) Selectivity (%) 1,6-Hexanediol yield (%) <![CDATA[0.05Pt / 2Cu / SiO2]]> 20.6 17.2 3.5 <![CDATA[0.2Pt / 2Cu / SiO2]]> 29.1 26.9 7.8 <![CDATA[0.6Pt / 2Cu / SiO2]]> 33.2 19.3 6.4 <![CDATA[1Pt / 2Cu / SiO2]]> 38.5 15.6 6.0

[0076] It can be seen from Table 2 that 0.2Pt / 2Cu / SiO2 has the best conversion rate and selectivity.

[0077] The effects of different metal oxide loadings on the dual-site single-atom catalysts are shown in Table 3. The reaction conditions are the same as those for the catalyst performance test.

[0078] Table 3 Effect of different metal oxide loadings on dual-site single atom catalysts

[0079] catalyst Conversion rate (%) Selectivity (%) 1,6-Hexanediol yield (%) <![CDATA[1Mo1O x -0.2Pt / 2Cu / SiO2]]> 62.3 75.3 46.9 <![CDATA[0.6Mo1O x -0.2Pt / 2Cu / SiO2]]> 67.1 84.5 56.7 <![CDATA[0.3Mo1O x -0.2Pt / 2Cu / SiO2]]> 73.5 86.1 63.3 <![CDATA[0.1Mo1O x -0.2Pt / 2Cu / SiO2]]> 86.2 90.3 77.8 <![CDATA[0.05Mo1O x -0.2Pt / 2Cu / SiO2]]> 75.2 78.6 59.1

[0080] It can be seen from Table 3 that 0.1Mo1O x -0.2Pt / 2Cu / SiO2 has the best conversion rate and selectivity, 0.3Mo1O x -0.2Pt / 2Cu / SiO2 and 0.05Mo1O x -0.2Pt / 2Cu / SiO2 also has certain activity.

[0081] The effects of different noble metal single atom loadings on the dual-site single atom catalyst are shown in Table 4. The reaction conditions are the same as the catalyst performance test.

[0082] Table 4 Effect of different noble metal single atom loadings on dual-site single atom catalysts

[0083] catalyst Conversion rate (%) Selectivity (%) 1,6-Hexanediol yield (%) <![CDATA[0.1Mo1O x -0.05Pt / 2Cu / SiO2]]> 71.1 80.4 57.2 <![CDATA[0.1Mo1O x -0.2Pt / 2Cu / SiO2]]> 86.2 90.3 77.8 <![CDATA[0.1Mo1O x -0.6Pt / 2Cu / SiO2]]> 88.5 85.6 75.8 <![CDATA[0.1Mo1O x -1Pt / 2Cu / SiO2]]> 89.7 73.8 66.2

[0084] It can be seen from Table 4 that 0.1Mo1O x -0.2Pt / 2Cu / SiO2 has the best conversion rate and selectivity, 0.1Mo1O x -0.6Pt / 2Cu / SiO2 and 0.1Mo1O x -1Pt / 2Cu / SiO2 also has certain activity.

[0085] Effects of different reaction pressures and reaction temperatures on the dual-site single-atom catalyst 0.1Mo1O x -0.2Pt / 2Cu / SiO2, see Tables 5 and 6, reaction conditions are the same as the catalyst performance test.

[0086] Table 5 Effect of different reaction pressures on 0.1Mo1O x -The influence of 0.2Pt / 2Cu / SiO2

[0087] Pressure(MPa) Conversion rate (%) Selectivity (%) 1,6-Hexanediol yield (%) 0.5 75.2 86.3 64.9 1 86.2 90.3 77.8 2 78.3 90.1 70.5 3 69.6 88.7 61.7 4 60.8 85.3 51.9

[0088] Note: The reaction temperature is 140°C.

[0089] Table 6 Effect of different reaction temperatures on 0.1Mo1O x -The influence of 0.2Pt / 2Cu / SiO2

[0090] Temperature(℃) Conversion rate (%) Selectivity (%) 1,6-Hexanediol yield (%) 100 57.1 84.6 48.3 120 74.3 91.4 67.9 140 86.2 90.3 77.8 160 95.3 77.7 74.0 180 97.6 65.3 63.7

[0091] Note: The reaction pressure is 1 MPa.

[0092] It can be seen from Tables 5 and 6 that when the reaction pressure is 1 MPa and the reaction temperature is 140 °C, 0.1Mo1O x -0.2Pt / 2Cu / SiO2 has the best selectivity and conversion rate.

[0093] The effects of different types of metal oxides on the catalyst are shown in Table 7. The reaction conditions are the same as those for the catalyst performance test.

[0094] Table 7 Effects of different types of metal oxides on catalysts

[0095] catalyst Conversion rate (%) Selectivity (%) 1,6-Hexanediol yield (%) <![CDATA[0.1Mo1O x -0.2Pt / 2Cu / SiO2]]> 86.2 90.3 77.8 <![CDATA[0.1W1O x -0.2Pt / 2Cu / SiO2]]> 78.3 82.7 64.8 <![CDATA[0.1Re1O x -0.2Pt / 2Cu / SiO2]]> 62.6 73.5 46.0 <![CDATA[0.1Ta1O x -0.2Pt / 2Cu / SiO2]]> 77.6 86.7 67.3 <![CDATA[0.1Nb1O x -0.2Pt / 2Cu / SiO2]]> 67.9 75.7 51.4

[0096] It can be seen from Table 7 that when different types of metal oxides are loaded, 0.1Mo1Ox -0.2Pt / 2Cu / SiO2 has the best conversion rate and selectivity.

[0097] The effects of different types of precious metals on the catalyst are shown in Table 8. The reaction conditions are the same as those for the catalyst performance test.

[0098] Table 8 Effects of different types of precious metals on catalysts

[0099]

[0100]

[0101] It can be seen from Table 8 that when different types of precious metals are loaded, 0.1Mo1O x -0.2Pt / 2Cu / SiO2 has the best conversion rate and selectivity.

Claims

1. Application of a dual-site single-atom catalyst in the selective hydrogenolysis of CO bonds of tetrahydrofuran dimethanol to prepare 1,6-hexanediol, characterized in that: The preparation method of the dual-site single-atom catalyst is specifically implemented according to the following steps: Step 1, using an impregnation method to load metal Cu nanoparticles on a SiO2 carrier to prepare Cu / SiO2; specifically: Dissolve and disperse the copper compound in a solvent to obtain a Cu precursor solution, immerse the SiO2 carrier in the Cu precursor solution for 4-20 hours, dry at 40-100°C for 4-10 hours, and treat at 350-550°C in a hydrogen or hydrogen-nitrogen mixed atmosphere for 0.5-5 hours to obtain Cu / SiO2; Step 2, dissolving the metal oxide precursor in a solvent to obtain a metal oxide precursor solution, adding Cu / SiO2 to the metal oxide precursor solution, stirring and reacting under the protection of an inert gas, filtering after the reaction, drying, and heat treating to obtain a catalyst M1O x / Cu / SiO2; The metal is any one of Mo, W, Re, Ta, and Nb; Step 3, dissolving the noble metal precursor in a solvent to obtain a noble metal precursor solution, and mixing M1O x / Cu / SiO2 is added to the noble metal precursor solution, stirred and reacted under the protection of inert gas, filtered after the reaction, dried, and heat-treated to obtain M1O x -M'1 / Cu / SiO2, which is a dual-site single-atom catalyst; The noble metal is any one of Pt, Pd, Rh, Ru, Ir and Ag; In steps 2 and 3, the heat treatment is: treating at 200-500° C. for 0.5-5 h in a hydrogen or nitrogen or a mixed atmosphere of the two.

2. The use according to claim 1, characterized in that: In the step 2, the reaction temperature is 20°C-100°C, and the reaction time is 0.5-6h; the drying temperature is 40-100°C, and the drying time is 4-10h.

3. The use according to claim 1, characterized in that: In step 3, the reaction temperature is 20° C.-100° C., and the reaction time is 0.5-6 h; the drying temperature is 40-100° C., and the drying time is 4-10 h.

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