A copper-palladium single-atom alloy catalyst and its preparation method and application
By preparing copper-palladium single-atom alloy catalysts, the problem of high precious metal loading in existing catalysts was solved, and the effect of low-cost and efficient furfural hydrogenation to produce furfuryl alcohol was achieved, and the catalyst had good recycling performance.
Patent Information
- Application Number
- CN202311528791.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2023-11-16
- Publication Date
- 2025-09-16
- Estimated Expiration
- 2043-11-16
AI Technical Summary
Existing catalysts have a high loading of precious metals in the process of catalytic hydrogenation of furfural to furfuryl alcohol, resulting in high production costs and insufficient catalytic selectivity.
A copper-palladium single-atom alloy catalyst is used, in which copper is in the form of nanoparticles and palladium is in the form of single atoms supported on silica, with an atomic ratio of palladium:copper = (0.006-0.025):1. A highly efficient copper-palladium single-atom alloy catalyst is prepared through a preparation method including mixed liquid preparation, calcination and reduction treatment.
The catalyst production cost is reduced, the catalytic activity and selectivity of furfural hydrogenation to furfuryl alcohol are improved, and the catalyst can be reused and maintains good circulation performance.
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Figure CN117504897B_ABST
Abstract
Description
Technical Field
[0001] The present invention belongs to the technical field of biomass conversion, and specifically relates to a copper-palladium single-atom alloy catalyst and a preparation method and application thereof. Background Art
[0002] With the growth of the global population and the development of the chemical industry, the consumption of non-renewable energy sources continues to increase, resource shortages are becoming increasingly severe, and the living environment is further deteriorating. Renewable lignocellulosic biomass is currently considered an effective alternative to fossil resources. Converting it into high-value-added chemicals is an important way to address the energy crisis and reduce environmental pollution. Furfural, a biomass product, can be selectively hydrogenated to furfuryl alcohol, a key chemical raw material.
[0003] In the catalytic hydrogenation of furfural to furfuryl alcohol, some existing catalysts are expensive to produce due to their high precious metal loading. In contrast, heterogeneous precious metal catalysts demonstrate excellent furfural hydrogenation performance. Among the numerous heterogeneous precious metal catalysts, single-atom alloy catalysts, with their high efficiency, highly active surface sites, and high atomic utilization, are among the best candidates for catalyzing this reaction. Single-atom alloy catalysts not only maximize the utilization of active sites but also reduce precious metal usage, lowering catalyst production costs while improving catalytic selectivity during the conversion process. Summary of the Invention
[0004] In order to solve the problems existing in the prior art, the purpose of the present invention is to provide a copper-palladium single-atom alloy catalyst and its preparation method and application.
[0005] To achieve the above object, the technical solution adopted by the present invention is as follows:
[0006] A copper-palladium single-atom alloy catalyst comprises a carrier and an active component. The carrier is silicon dioxide, and the active component is a copper-palladium bimetallic. The palladium is supported on the silicon dioxide in the form of single atoms, and the copper is supported on the silicon dioxide in the form of nanoparticles. The atomic ratio is palladium:copper = (0.006-0.025):1. The copper loading is 1-10 wt% (the loading is calculated as a percentage of the mass of the carrier).
[0007] The preparation method of the copper-palladium single-atom alloy catalyst comprises the following steps:
[0008] (I) Preparation of copper-palladium bimetallic mixed solution:
[0009] Palladium acetate, copper acetate, and 1,10-phenanthroline are added to dimethyl sulfoxide and stirred to dissolve. Subsequently, silica sol is added and heated and stirred for 4-5 hours to obtain a copper-palladium bimetallic mixed solution. The raw material ratio is palladium acetate: copper acetate: 1,10-phenanthroline: dimethyl sulfoxide: silica sol = (0.01-0.04) mol: 1.6 mol: (40-80) mg: (10-30) mL: (1-10) g.
[0010] (II) Preparation of copper-palladium single-atom alloy catalyst:
[0011] The solvent in the copper-palladium bimetallic mixture obtained in step (I) is evaporated and removed, the mixture is cooled to room temperature, ground, calcined in air at 400-500°C for 2-3 h, and washed; subsequently, the mixture is reduced in a H2 / inert gas mixed atmosphere at 230-250°C for 90-120 min to obtain a copper-palladium single-atom alloy catalyst.
[0012] Preferably, in step (I), the temperature for heating and stirring is 60-80°C.
[0013] Preferably, in step (I), the silica sol is composed of a silica sol having a specific surface area of 450-500 m 2 / g of silicon dioxide is mixed with water, wherein the concentration of silicon dioxide is 40-50 wt%.
[0014] Preferably, in step (II), the copper-palladium bimetallic mixed solution obtained in step (I) is heated to above the melting point of dimethyl sulfoxide, heated for 10-12 h, and the solvent is removed.
[0015] Preferably, in step (II), washing is performed first with water and then with ethanol.
[0016] Preferably, in step (II), the proportion of H2 in the H2 / inert gas mixed atmosphere is 10-20 v%.
[0017] Application of the copper-palladium single-atom alloy catalyst in the hydrogenation of furfural to furfuryl alcohol.
[0018] Preferably, the catalyst, isopropanol, and furfural are placed in a high-pressure reactor, hydrogen is introduced therein, and the reaction is carried out for 2-3 hours under the conditions of a hydrogen pressure of 1-2 MPa, a rotation speed of 800-900 rpm, and a temperature of 90-110°C; wherein the raw material ratio is catalyst: isopropanol: furfural = (0.3-0.5) g: (28-30) mL: (0.8-0.9) mL.
[0019] Beneficial effects: The catalyst prepared by the present invention uses low-cost materials, can be reused, and exhibits excellent catalytic activity in the furfural hydrogenation reaction process; at the same time, the yield and selectivity of the target product in the reaction process of furfural hydrogenation to furfuryl alcohol can be further adjusted by controlling the atomic ratio of copper and palladium metals. BRIEF DESCRIPTION OF THE DRAWINGS
[0020] Figure 1 High-angle annular dark-field scanning transmission electron microscopy image (a) of the copper-palladium single-atom alloy catalyst with an atomic ratio of Pd:Cu = 0.006 prepared in Example 1 and the corresponding element distribution maps (bd).
[0021] Figure 2 H2-TPR spectra of the catalysts prepared in Examples 1-3 and Comparative Example 1: (a) copper-based catalyst prepared in Comparative Example 1, (b) copper-palladium single-atom alloy catalyst with an atomic ratio of Pd:Cu = 0.006 prepared in Example 1, (c) copper-palladium single-atom alloy catalyst with an atomic ratio of Pd:Cu = 0.015 prepared in Example 2, (d) copper-palladium single-atom alloy catalyst with an atomic ratio of Pd:Cu = 0.025 prepared in Example 3. DETAILED DESCRIPTION
[0022] The present invention is described in detail below through specific examples, in which many specific details are set forth to provide a full understanding of the objects, features, and advantages of the present invention. However, these examples are intended only to illustrate the present invention and are not intended to limit the actual scope of protection of the present invention in any form. Those skilled in the art may implement any form of changes and modifications to the present invention without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific examples disclosed below.
[0023] Example 1
[0024] The preparation method of a copper-palladium single-atom alloy catalyst with an atomic ratio of Pd:Cu = 0.006 comprises the following steps:
[0025] (I) Preparation of copper-palladium bimetallic mixed solution:
[0026] 2.1 mg of palladium acetate, 314.2 mg of copper acetate monohydrate and 60 mg of 1,10-phenanthroline were dissolved in 20 mL of dimethyl sulfoxide and dissolved under magnetic stirring. Then, 5 g of silica sol was added and magnetically stirred in an oil bath at 60 °C for 4 h to obtain a copper-palladium bimetallic mixed solution. The silica sol was composed of a copper-palladium bimetallic mixed solution with a specific surface area of 450-500 m 2 / g of fumed silica and water, wherein the concentration of fumed silica is 40 wt%;
[0027] (II) Preparation of copper-palladium single-atom alloy catalyst:
[0028] The copper-palladium bimetallic mixture obtained in step (I) was heated to 190°C for 10 h to obtain solid particles. The solid particles were cooled to room temperature and ground in a mortar. The solid particles were calcined in air at 450°C for 2 h, and then centrifuged and washed five times with deionized water and then with anhydrous ethanol. Subsequently, the mixture was reduced at 250°C for 90 min in a 10 v% H2 / He atmosphere to obtain a copper-palladium single-atom alloy catalyst.
[0029] Example 2
[0030] The method for preparing a copper-palladium single-atom alloy catalyst with an atomic ratio of Pd:Cu = 0.015 is different from that of Example 1 in that in step (I), the amount of palladium acetate is changed to 5.3 mg.
[0031] Example 3
[0032] The method for preparing a copper-palladium single-atom alloy catalyst with an atomic ratio of Pd:Cu = 0.025 is different from that of Example 1 in that in step (I), the amount of palladium acetate is changed to 8.9 mg.
[0033] Comparative Example 1
[0034] The preparation method of the copper-based catalyst comprises the following steps:
[0035] (I) Preparation of copper-based mixed solution:
[0036] 314.2 mg of copper acetate monohydrate and 60 mg of 1,10-phenanthroline were dissolved in 20 mL of dimethyl sulfoxide and dissolved under magnetic stirring. Then, 5 g of silica sol was added and magnetically stirred in an oil bath at 60 °C for 4 h to obtain a copper-based mixed solution. The silica sol was composed of a specific surface area of 450-500 m 2 / g of fumed silica and water, wherein the concentration of fumed silica is 40 wt%;
[0037] (II) Preparation of copper-based catalyst:
[0038] The copper-based mixed solution obtained in step (I) was heated to 190°C for 10 hours to obtain solid particles. After cooling to room temperature, the solid particles were ground in a mortar and calcined at 450°C in air for 2 hours. The solid particles were centrifugally washed five times with deionized water and then with anhydrous ethanol. Subsequently, the solid particles were reduced at 250°C for 90 minutes in a 10 v% H2 / He atmosphere to obtain a copper-based catalyst.
[0039] Comparative Example 2
[0040] The preparation method of palladium-based catalyst comprises the following steps:
[0041] (I) Preparation of palladium-based mixed solution:
[0042] 211.0 mg of palladium acetate and 60 mg of 1,10-phenanthroline were dissolved in 20 mL of dimethyl sulfoxide and dissolved under magnetic stirring. Then, 5 g of silica sol was added and magnetically stirred in an oil bath at 60 °C for 4 h to obtain a palladium-based mixed solution. The silica sol was composed of a silica sol with a specific surface area of 450-500 m 2 / g of fumed silica is mixed with water, wherein the concentration of fumed silica is 40wt%;
[0043] (II) Preparation of palladium-based catalyst:
[0044] The palladium-based mixed solution obtained in step (I) was heated to 190°C for 10 h to obtain solid particles. After cooling to room temperature, the solid particles were ground in a mortar and calcined in air at 450°C for 2 h, and then centrifugally washed five times with deionized water and then with anhydrous ethanol; subsequently, the solid particles were pre-reduced at 250°C for 90 min in a 10 v% H2 / He atmosphere to obtain a palladium-based catalyst.
[0045] Figure 1 High-angle annular dark field scanning transmission electron microscopy image (a) and corresponding element distribution map (bd) of the copper-palladium single-atom alloy catalyst with an atomic ratio of Pd:Cu = 0.006 prepared in Example 1. Figure 1 As can be seen in the figure: palladium is loaded on silica in the form of single atoms, and copper is loaded on silica in the form of nanoparticles.
[0046] Figure 2 H2-TPR spectra of the catalysts prepared in Examples 1-3 and Comparative Example 1: (a) copper-based catalyst prepared in Comparative Example 1, (b) copper-palladium single-atom alloy catalyst with an atomic ratio of Pd:Cu = 0.006 prepared in Example 1, (c) copper-palladium single-atom alloy catalyst with an atomic ratio of Pd:Cu = 0.015 prepared in Example 2, (d) copper-palladium single-atom alloy catalyst with an atomic ratio of Pd:Cu = 0.025 prepared in Example 3. Figure 2 It can be concluded that the copper-based catalyst (a) only has a reduction peak near 310 °C, but the reduction peaks of the copper-palladium single-atom alloy catalysts with atomic ratios of Pd:Cu = 0.006 (b), 0.015 (c) and 0.025 (d) gradually move to lower temperatures with the addition of palladium, which indicates that there is an interaction between copper and palladium atoms, and the introduction of palladium promotes the uniform dispersion of copper.
[0047] Application Examples
[0048] The catalysts prepared in Examples 1-3 and Comparative Examples 1-2 were used as application objects, and the steps were as follows:
[0049] 0.3 g of catalyst, 28 mL of isopropanol, and 0.87 mL of furfural were placed in a high-pressure reactor, and hydrogen was introduced into the reactor. The reaction was carried out at a hydrogen pressure of 1 MPa, a rotation speed of 800 rpm, and a temperature of 110°C for 2 h. After the reaction, the reaction liquid was filtered and separated. The separated solid was washed and dried to obtain the regenerated catalyst, which was used for the next reaction. At the same time, the separated liquid was sampled, and the furfural conversion rate and furfuryl alcohol selectivity were determined by gas chromatography.
[0050] Table 1 shows the furfural conversion and furfural alcohol selectivity of the catalysts prepared in Examples 1-3 and Comparative Examples 1-2. It can be seen that, under identical reaction conditions, the furfural conversion and furfural alcohol selectivity of the copper-palladium single-atom alloy catalysts prepared in Examples 1-3 were significantly higher than those of the copper-based catalyst or palladium-based catalyst prepared in Comparative Examples 1-2 alone. Furthermore, the copper-palladium single-atom alloy catalyst achieved the highest conversion and selectivity when the atomic ratio Pd:Cu was 0.006 (Example 1).
[0051]
[0052] Table 2 shows the cyclic performance of the catalysts prepared in Example 1 and Comparative Example 1. It can be seen that after five cycles, the activity and selectivity of the catalyst in Example 1 remained virtually unchanged, while the activity and cyclic stability of the catalyst in Comparative Example 1 showed a significant decrease. This fully demonstrates that the copper-palladium single-atom alloy catalyst prepared in this invention exhibits excellent cyclic performance and is reusable, demonstrating excellent catalytic activity in the hydrogenation of furfural to furfuryl alcohol.
[0053]
Claims
1. A method for preparing a copper-palladium single-atom alloy catalyst, characterized in that: The catalyst comprises a carrier and an active component. The carrier is silicon dioxide, and the active component is a copper-palladium bimetallic material. The palladium is supported on the silicon dioxide in the form of single atoms, and the copper is supported on the silicon dioxide in the form of nanoparticles. The atomic ratio is palladium:copper = (0.006-0.025):
1. The copper loading is 1-10 wt%. The preparation steps are as follows: (I) Preparation of copper-palladium bimetallic mixed solution: Palladium acetate, copper acetate, and 1,10-phenanthroline are added to dimethyl sulfoxide and stirred to dissolve. Subsequently, silica sol is added and heated and stirred for 4-5 hours to obtain a copper-palladium bimetallic mixed solution. The raw material ratio is palladium acetate: copper acetate: 1,10-phenanthroline: dimethyl sulfoxide: silica sol = (0.01-0.04) mol: 1.6 mol: (40-80) mg: (10-30) mL: (1-10) g. (II) Preparation of copper-palladium single-atom alloy catalyst: The solvent in the copper-palladium bimetallic mixture obtained in step (I) is evaporated and removed, the mixture is cooled to room temperature, ground, calcined in air at 400-500°C for 2-3 h, and washed; subsequently, the mixture is reduced in a H2 / inert gas mixed atmosphere at 230-250°C for 90-120 min to obtain a copper-palladium single-atom alloy catalyst.
2. The method for preparing the copper-palladium single-atom alloy catalyst according to claim 1, wherein: In step (I), the temperature for heating and stirring is 60-80°C.
3. The method for preparing the copper-palladium single-atom alloy catalyst according to claim 1, wherein: In step (I), the silica sol is composed of a silica sol having a specific surface area of 450-500 m 2 / g of silicon dioxide is mixed with water, wherein the concentration of silicon dioxide is 40-50 wt%.
4. The method for preparing the copper-palladium single-atom alloy catalyst according to claim 1, wherein: In step (II), the copper-palladium bimetallic mixed solution obtained in step (I) is heated to above the melting point of dimethyl sulfoxide, heated for 10-12 hours, and the solvent is removed.
5. The method for preparing the copper-palladium single-atom alloy catalyst according to claim 1, wherein: In step (II), during washing, the sample is first washed with water and then with ethanol.
6. The method for preparing the copper-palladium single-atom alloy catalyst according to claim 1, wherein: In step (II), the proportion of H2 in the H2 / inert gas mixed atmosphere is 10-20 v%.