Method for preparing rare earth metal monatomic catalyst by electrochemical method
The preparation of rare earth metal single atom catalysts through electrochemical methods solved the problem of high exposure rate and stable load on the support materials, and achieved efficient and low-cost catalyst preparation and multi-atom synergy.
Patent Information
- Application Number
- CN202510405784.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-04-02
- Publication Date
- 2025-07-04
AI Technical Summary
The prior art is difficult to effectively prepare rare earth metal single-atom catalysts, which leads to insufficient activity in catalytic reactions, and it is difficult to achieve high exposure rate and stable load of rare earth metals on support materials by high temperature pyrolysis.
The rare earth metal single atom catalyst was prepared by electrochemical method, and the rare earth metal salt was deposited on the support material and combined with the post-deposition method to load other metal single atoms. The electrochemical method was used to achieve high exposure and loading of rare earth metal single atoms at room temperature.
It realizes efficient preparation of rare earth metal single-atom catalysts, reduces energy consumption, improves catalytic activity, and promotes multi-atom synergy, and the preparation process is simple and low-cost.
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Figure CN120250054A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of hydrogen evolution by water electrolysis and electrocatalysis in the chlor-alkali industry, and specifically relates to a method for preparing rare-earth metal single-atom catalysts by an electrochemical method. Background Art
[0002] Single-atom catalysts (SACs) that uniformly disperse active metals in the form of single atoms on supports have become a frontier hotspot in the field of catalysis science. The uniqueness of this catalyst lies in its low loading and high atomic utilization efficiency, making the application of expensive platinum-group metals in industrial catalysis more economical and extensive. The rise of rare-earth metal single-atom catalysts has opened up a new path for the research of SACs. Rare-earth metals are the collective name of 17 chemical elements, namely scandium, yttrium and the lanthanide elements in Group III of the periodic table. They are scandium (Sc), yttrium (Y), lanthanum (La), cerium (Ce), praseodymium (Pr), neodymium (Nd), promethium (Pm), samarium (Sm), europium (Eu), gadolinium (Gd), terbium (Tb), dysprosium (Dy), holmium (Ho), erbium (Er), thulium (Tm), ytterbium (Yb), lutetium (Lu). Rare-earth metals have shown extraordinary potential in the catalytic field due to their unique electronic structures and chemical properties. Although they are not usually the main active sites, when rare-earth metals are introduced into the catalytic system, they can often significantly enhance the overall catalytic activity. This is mainly attributed to the regulation and optimization of the key steps in the catalytic reaction process by rare-earth metals. However, the preparation of rare-earth metal single atoms still faces many challenges. Due to the low standard reduction potential of rare-earth metals (< -1.9 V), traditional preparation methods are limited to the preparation of rare-earth metal single atoms by high-temperature pyrolysis of the mixture of metal salts and support precursors. Although this method can prepare rare-earth metal single-atom catalysts, some single atoms are often buried inside and cannot be fully exposed, thus limiting the exertion of their catalytic activity. And it is difficult to load rare-earth metal single atoms on single-atom support materials that are unstable at high temperatures. Therefore, in order to improve the exposure rate and utilization rate of single atoms and strengthen the synergy with other metal single atoms, thereby further enhancing the catalytic performance, it is still very necessary to actively explore new methods for preparing rare-earth metal single atoms. Summary of the Invention
[0003] Aiming at the above deficiencies in the prior art, the purpose of the present invention is to provide a method for preparing rare-earth metal single-atom catalysts by an electrochemical method.
[0004] To achieve the above invention purpose, the technical solution adopted by the present invention is as follows:
[0005] Provide a method for preparing rare-earth metal single-atom catalysts by an electrochemical method, which includes the following steps:
[0006] (1) Dissolve rare-earth metal salts in an electrolyte solution sufficiently;
[0007] (2) Using the carrier material as the working electrode, a carbon rod as the counter electrode, and a saturated calomel electrode as the reference electrode, one or more rare earth metal salts are dispersed in the electrolyte, and a rare earth metal single-atom catalyst is prepared by one-step electrochemical deposition; or the rare earth metal salt is first deposited with the first metal single atom by electrochemical deposition, and then the second or more metal single atoms are loaded by post-deposition to obtain a composite single-atom catalyst containing rare earth metal single atoms.
[0008] Further, in step (1), the concentration of the rare earth metal salt is 0-100 mol / L.
[0009] Further, in step (1), the rare earth metal salt is a chloride, sulfate or nitrate.
[0010] Further, in step (1), the electrolyte solution is an organic system or an aqueous system. The solvent used in the organic system is N,N-dimethylformamide, dimethyl sulfoxide or dimethyl methyl ether; the additives used in the aqueous system are citric acid, trisodium citrate, ascorbic acid or tartaric acid.
[0011] Further, in step (2), the deposition method is cyclic voltammetry scanning, constant current deposition or constant voltage deposition.
[0012] Further, in step (2), the post-deposition method is an electrochemical deposition method or an atomic layer deposition method.
[0013] Further, in step (2), the types of the second metal single atoms include platinum group metals Pt / Ir / Ru / Rh / Pd / Os.
[0014] Further, in step (2), the carrier material includes a carbon-based carrier, transition metal alloys and their oxides, nitrides, borides, phosphides, sulfides, selenides, tellurides and halides.
[0015] The beneficial effects of the present invention are as follows:
[0016] (1) Realize the universal preparation of single-atom catalysts of rare earth metals with low electrode potentials by electrochemical methods;
[0017] (2) The energy consumption in the preparation process is low, and the required temperature for preparation is only room temperature;
[0018] (3) Use inexpensive electrolytes instead of expensive ionic liquids; the rare earth metal single atoms deposited on the carrier surface by electrochemical methods have high exposure characteristics;
[0019] (4) The carrier loaded with rare earth metal single atoms can also be subjected to secondary single-atom deposition, and atomic dimers or polymers can be constructed, which is beneficial to promoting multi-atom cooperation;
[0020] (5) It is possible to achieve the one-step preparation of rare-earth metal high-entropy single-atom catalysts. Description of the Drawings
[0021] Figure 1 AC-TEM image and EDS mapping image of the carbon nanotube-supported Ce single-atom catalyst prepared in the example;
[0022] Among them, a is the aberration-corrected TEM image of Pt-Ce-CNT@Ti, and the bright spots at the atomic scale therein are the electrochemically synthesized Ce single atoms; b is the longitudinal intensity map of a single Ce single atom in the rectangular selection area corresponding to a; c is the EDS elemental imaging map of Pt-Ce-CNT@Ti.
[0023] Figure 2 Schematic diagram of the HER performance and Pt mass activity statistical results of the carbon nanotube-supported Ce single atom and other rare-earth metal single atoms and Pt single atom co-catalyst prepared in the example;
[0024] Among them, a is the LSV result of Pt-Ce-CNT@Ti and its reference catalyst; b is the Pt mass activity result of Pt-Ce-CNT@Ti and Pt-CNT@Ti; c is the Pt mass activity statistical result of Pt-Ln-CNT@Ti of all lanthanide metal single atoms. Detailed Embodiments
[0025] The following describes the specific embodiments of the present invention to facilitate those skilled in the art of the present technology to understand the present invention. However, it should be clear that the present invention is not limited to the scope of the specific embodiments. For those of ordinary skill in the art of the present technology, as long as various changes are within the spirit and scope of the present invention defined and determined by the appended claims, these changes are obvious, and all inventions and creations using the concept of the present invention are within the scope of protection.
[0026] Example 1
[0027] A method for preparing a rare-earth metal single-atom catalyst (Pt-Ce-CNT@Ti) by an electrochemical method, which includes the following steps:
[0028] (1) Dissolve 10 mM CeCl3 in the electrolyte solution N,N-dimethylformamide (DMF) sufficiently;
[0029] (2) Using the carrier material carbon nanotube (CNT) as the working electrode, a carbon rod as the counter electrode, and a saturated calomel electrode as the reference electrode, deposit and prepare a rare-earth metal single-atom catalyst by an electrochemical method;
[0030] Electrochemical deposition method: Taking Pt as an example, the deposition solution can be acidic, neutral, and alkaline solutions, and the Pt source can be chloroplatinic acid, platinum acetylacetonate, or tetraammineplatinum hydroxide. Concentration: 0 - 100 M. The electrochemical deposition method can be constant current (-1000 to 1000 mA / cm 2 , time: 0 - 100 hours), constant voltage (-0.4 to 0.4 V vs. RHE, time: 0 - 100 hours), and cyclic voltammetry scanning method (potential range: -4 V to 4 V vs. RHE, scan rate: 0 - 1000 mV / s, number of cycles: 0 - 10000 cycles).
[0031] (3) Load the second metal single - atom platinum - group metal Pt onto the rare - earth metal single - atom material prepared by electrochemical deposition in step 2 through post - deposition method (atomic layer deposition method) to obtain a composite single - atom catalyst Pt - Ce - CNT@Ti containing rare - earth metal single atoms.
[0032] Atomic layer deposition method: The Pt source is trimethylmethylcyclopentadienyl platinum ((MeCp)Pt(Me)3), platinum acetylacetonate. Deposition parameters: Place the Ti - based electrode directly in the ALD reaction chamber, control the deposition temperature at 50 - 500 °C, and control the chamber pressure at 0 - 200 Pa. During deposition, the Pt source and O2 are alternately sprayed into the chamber, and the number of deposition cycles is 1 - 100 cycles.
[0033] Example 2
[0034] A method for preparing a rare - earth metal single - atom catalyst (Pt - Tm - CNT@Ti) by electrochemical method, which includes the following steps:
[0035] (1) Dissolve 10 mM TmCl3 fully in the electrolyte solution N,N - dimethylformamide (DMF).
[0036] (2) Use the carrier material carbon nanotubes (CNT) as the working electrode, a carbon rod as the counter electrode, and a saturated calomel electrode as the reference electrode to deposit and prepare a rare - earth metal single - atom catalyst by electrochemical method.
[0037] Electrochemical deposition method: Taking Pt as an example, the deposition solution can be acidic, neutral, and alkaline solutions, and the Pt source can be chloroplatinic acid, platinum acetylacetonate, or tetraammineplatinum hydroxide. Concentration: 0 - 100 M. The electrochemical deposition method can be constant current (-1000 to 1000 mA / cm 2 , time: 0 - 100 hours), constant voltage (-0.4 to 0.4 V vs. RHE, time: 0 - 100 hours), and cyclic voltammetry scanning method (potential range: -4 V to 4 V vs. RHE, scan rate: 0 - 1000 mV / s, number of cycles: 0 - 10000 cycles).
[0038] (3) The rare-earth metal single-atom material prepared by electrochemical deposition in step 2 is loaded with the second metal single-atom platinum group metal Pt by post-deposition method (atomic layer deposition method) to obtain a composite single-atom catalyst Pt-Tm-CNT@Ti containing rare-earth metal single atoms.
[0039] Atomic layer deposition method: The Pt source is trimethylmethylcyclopentadienyl platinum ((MeCp)Pt(Me)3) and platinum acetylacetonate. Deposition parameters: The Ti-based electrode is directly placed in the ALD reaction chamber, the deposition temperature is controlled at 50 - 500 °C, and the chamber pressure is controlled at 0 - 200 Pa. During deposition, the Pt source and O2 are alternately sprayed into the chamber, and the number of deposition cycles is 1 - 100 cycles.
[0040] Comparative example
[0041] Using the carrier material carbon nanotubes (CNT) as the working electrode, a carbon rod as the counter electrode, and a saturated calomel electrode as the reference electrode, Pt-CNT@Ti is prepared by atomic layer deposition method.
[0042] Atomic layer deposition method: The Pt source is trimethylmethylcyclopentadienyl platinum ((MeCp)Pt(Me)3) and platinum acetylacetonate. Deposition parameters: The Ti-based electrode is directly placed in the ALD reaction chamber, the deposition temperature is controlled at 50 - 500 °C, and the chamber pressure is controlled at 0 - 200 Pa. During deposition, the Pt source and O2 are alternately sprayed into the chamber, and the number of deposition cycles is 1 - 100 cycles.
[0043] Test example
[0044] The composite single-atom catalyst prepared in the example is tested.
[0045] Figure 1 It shows that the Ce element is evenly distributed on the surface of CNT. Figure 2 Figure a shows the LSV results of Pt-Ce-CNT@Ti and its reference catalyst. It can be seen that Pt-Ce-CNT@Ti has the best hydrogen evolution activity, and the overpotential at 300 mA / cm 2 is 59 mV vs RHE. Figure 2 Figure b shows the Pt mass activity results of Pt-Ce-CNT@Ti and Pt-CNT@Ti. It can be seen that due to the existence and synergy of Ce single atoms, the Pt mass activity in Pt-Ce-CNT@Ti is 31.8 A / mg Pt @50 mV and 115.5 A / mg Pt @100 mV. Figure 2Among them, c is the statistical result of the Pt mass activity of Pt-Ln-CNT@Ti with all lanthanide metal single atoms. The results show that Pt-Ln-CNT@Ti with the coexistence of Tm and Ce single atoms has the best hydrogen evolution performance. Among them, the Pt mass activity of Pt-Ce-CNT@Ti is 31.8 A / mg Pt @50 mV, the Pt mass activity of Pt-Tm-CNT@Ti is 35.9 A / mg Pt @50 mV.
[0046] In summary, the method of the present invention can prepare rare earth metal single atom catalysts with extremely low standard electrode potentials, which can not only reduce the energy consumption in the preparation process, but also realize the loading and exposure of rare earth metal single atoms on the surface of the carrier at room temperature, and then cooperate with other transition metal single atoms.
[0047] For those skilled in the art, it is obvious that the present invention is not limited to the details of the above exemplary embodiments, and can be implemented in other specific forms without departing from the spirit or basic characteristics of the present invention. Therefore, from any point of view, the embodiments should be regarded as exemplary and non-restrictive. The scope of the present invention is defined by the appended claims rather than the above description. Therefore, all changes falling within the meaning and scope of the equivalent elements of the claims are intended to be included in the present invention.
[0048] In addition, it should be understood that although this specification is described according to embodiments, not every embodiment only contains an independent technical solution. This narrative way of the specification is only for clarity. Those skilled in the art should regard the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.
Claims
1. A method for preparing rare earth metal single-atom catalysts by an electrochemical method, characterized in that, It includes the following steps: (1) Dissolve the rare earth metal salt sufficiently in the electrolyte solution; (2) Using the carrier material as the working electrode, the carbon rod as the counter electrode, and the saturated calomel electrode as the reference electrode, disperse one or more rare earth metal salts in the electrolyte, and deposit and prepare the rare earth metal single-atom catalyst by one-step electrochemical method; or deposit the rare earth metal salt by electrochemical method to first load the first metal single atom, and then load the second or more metal single atoms by post-deposition method to obtain the composite single-atom catalyst containing rare earth metal single atoms.
2. The method for preparing a rare earth metal single-atom catalyst by an electrochemical method according to claim 1, characterized in that, In step (1), the concentration of the rare earth metal salt is 0-100 mol / L.
3. The method for preparing a rare earth metal single-atom catalyst by an electrochemical method according to claim 1, characterized in that, In step (1), the rare earth metal salt is chloride, sulfate or nitrate.
4. The method for preparing a rare earth metal single-atom catalyst by an electrochemical method according to claim 1, characterized in that, In step (1), the electrolyte solution is an organic system or an aqueous system. The solvent used in the organic system is N, N-dimethylformamide, dimethyl sulfoxide or dimethyl methyl ether; the additives used in the aqueous system are citric acid, trisodium citrate, ascorbic acid or tartaric acid.
5. The method for preparing a rare earth metal single-atom catalyst by an electrochemical method according to claim 1, wherein, In step (2), the deposition method is cyclic voltammetry scanning, constant current deposition or constant voltage deposition.
6. The method for preparing a rare earth metal single-atom catalyst by an electrochemical method according to claim 1, wherein In step (2), the post-deposition method is electrochemical deposition method or atomic layer deposition method.
7. The method for preparing a rare earth metal single-atom catalyst by an electrochemical method according to claim 1, characterized in that, In step (2), the types of the second metal single atoms include platinum group metals Pt / Ir / Ru / Rh / Pd / Os.
8. The method for preparing a rare earth metal single-atom catalyst by an electrochemical method according to claim 1, characterized in that, In step (2), the carrier material includes carbon-based carriers, transition metal alloys and their oxides, nitrides, borides, phosphides, sulfides, selenides, tellurides and halides.