Preparation method of controllable carbon layer loaded monatomic titanium-based electrode
By preparing carbon coated materials on a titanium substrate and loading single atoms, the problem of uneven distribution of precious metals on the electrode substrate is solved, and efficient single atom catalyst application is achieved, suitable for membrane electrode assembly.
Patent Information
- Application Number
- CN202510405787.8
- 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 achieve uniform distribution and efficient utilization of precious metal single atoms on electrode substrates, especially the controllability of graphene layers grown on acid-resistant metals, which affects catalytic performance.
A carbon coated material was prepared on a titanium substrate by one-step high-temperature pyrolysis method, and single atoms were loaded through post-deposition method. The uniform distribution of precious metal atoms was achieved on the single layer of graphene by electrochemical or atomic layer deposition method, and their interaction with the substrate was optimized.
It realizes efficient utilization of precious metal atoms, improves catalytic performance, and reduces production costs, and is suitable for high-performance single-atom catalysts for membrane electrode assemblies.
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Figure CN120250035A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of hydrogen evolution by electrocatalysis in water electrolysis and chlor-alkali industry, and particularly relates to a preparation method of a titanium-based electrode loaded with single atoms by a controllable carbon layer. Background Art
[0002] The core feature of single-atom catalysts (SACs) is that active metal atoms are uniformly and stably dispersed on the carrier material in a single form. This unique structure endows SACs with many significant advantages. First of all, the metal loading of SACs is extremely low, which directly means that the amount of precious metals required is greatly reduced on the premise of achieving the same catalytic effect. For the expensive platinum-group metals, this characteristic undoubtedly opens up a new path for their wide application in the field of industrial catalysis, greatly reducing the production cost and improving the economic benefits. Secondly, SACs exhibit extremely high atomic utilization efficiency. Since each metal atom participates in the catalytic reaction as an independent active site, SACs can give full play to the catalytic potential of each atom more fully compared with the situation where metal atoms often exist in the form of agglomerates or particles in traditional catalysts, thus improving the overall catalytic efficiency. However, the catalytic performance of SACs does not exist in isolation, but is closely related to its coordination environment and carrier material. The coordination environment determines the electronic structure and chemical properties of metal atoms, thereby affecting their catalytic activity. The carrier material bears the responsibility of supporting and dispersing metal atoms. At the same time, the interaction between the carrier and metal atoms may further regulate the catalytic performance. In this context, highly graphitized carbon materials, especially graphene, have become ideal carriers for SACs due to their unique physical and chemical properties. Graphene not only has excellent electrical conductivity and mechanical strength, but also is easy to introduce heteroatoms (such as nitrogen, oxygen, sulfur, etc.) through chemical modification, thereby precisely regulating the coordination structure of metal atoms. This regulation not only helps to optimize the catalytic performance, but may also trigger new catalytic mechanisms and reaction paths. In addition, graphene as a carrier can also firmly load SACs on the electrode material to construct a stable and efficient carbon-supported single-atom electrode. This enables SACs to show broad application prospects in the fields of electrocatalytic, energy conversion and storage. For example, in key technologies such as fuel cells, water electrolysis for hydrogen production, and lithium-ion batteries, SACs are expected to replace traditional catalysts to achieve a more efficient and environmentally friendly catalytic process. In summary, single-atom catalysts are gradually becoming a research hotspot in the field of catalytic science with their unique structure and significant catalytic advantages. And highly graphitized carbon materials, especially graphene as an ideal carrier for SACs, not only provide a new way for the performance optimization of SACs, but also lay a solid foundation for their wide application in the fields of industrial catalysis, electrocatalytic, etc.
[0003] Generally, the catalytic materials for in-situ growing graphene on the electrode substrate mainly aggregate on acid-intolerant metals such as iron (Fe), cobalt (Co), nickel (Ni), and copper (Cu). These metals have a low carbon solubility and can catalyze the decomposition of the carbon source at high temperatures, thereby forming graphene on the substrate. However, the graphene grown by these metal catalysis is often mainly composed of multi-layer carbon with poor controllability of the number of layers, and it will also affect its composite effect with other materials. Moreover, common high-temperature pyrolysis schemes often make the loaded metal single atoms unable to be fully exposed on the outermost surface, affecting the atomic utilization rate. Summary of the Invention
[0004] Aiming at the above deficiencies in the prior art, the purpose of the present invention is to provide a preparation method of a titanium-based electrode with single atoms loaded on a controllable carbon layer.
[0005] In order to achieve the above invention purpose, the technical scheme adopted by the present invention is as follows:
[0006] Provide a preparation method of a titanium-based electrode with single atoms loaded on a controllable carbon layer, which includes the following steps:
[0007] (1) Place the solid-phase carbon source and the acid-treated titanium substrate at the inlet of the tube furnace and the heating temperature zone respectively;
[0008] (2) Introduce an inert gas and a certain proportion of hydrogen, heat the tube furnace to 600 - 1200 °C, and keep it for 0 - 300 min; after natural cooling, obtain a carbon-coated titanium-based material;
[0009] (3) Load single atoms on the single-layer, few-layer, and multi-layer carbon-coated titanium-based electrodes of the carbon-coated titanium-based material by post-deposition method.
[0010] Further, in step (1), the solid-phase carbon source is melamine, dicyandiamide, urea, or guanidine hydrochloride.
[0011] Further, in step (2), the inert gas is argon or nitrogen; the volume ratio of hydrogen is 0 - 100%.
[0012] Further, in step (3), the post-deposition method is an electrochemical deposition method or an atomic layer deposition method; it can realize the one-step or step-by-step deposition of various single atoms, and realize the loading of low, medium, and high entropy single atoms on the single-layer carbon carrier.
[0013] Further, in step (3), the types of single atoms include platinum group metals Pt / Ir / Ru / Rh / Pd / Os.
[0014] The beneficial effects of the present invention are as follows:
[0015] (1) Prepare a non-iron-cobalt-nickel-based graphitized carbon material by one-step high-temperature pyrolysis;
[0016] (2) Preparation of electrode materials with controllable carbon layer coating by ordinary heating equipment;
[0017] (3) The materials directly applicable to the membrane electrode assembly are used as the base electrode, such as titanium-based materials;
[0018] (4) A single-atom catalyst that simply and easily controls the loading of single atoms on a single layer of carbon and coats the substrate;
[0019] (5) Realize the loading of multiple metals in the form of single atoms on a single-layer carbon-based material, such as all platinum group metals;
[0020] (6) Can regulate the longitudinal spatial distance between single-atom sites and the substrate, optimize the coordination environment of single-atom sites and their interaction with the substrate;
[0021] (7) Can realize the loading of high-entropy single atoms on a single layer of carbon. Description of the Drawings
[0022] Figure 1 Ti substrate coated with carbon film prepared in Example 1 (a); SEM image of carbon-coated titanium nitride nanorods with an average diameter of 130 nm (b); SEM image and Raman spectrum of carbon-coated titanium nitride nanowires with an average diameter of 51 nm (c-d); TEM images of titanium nitride nanowires with different carbon layer thicknesses (e-h);
[0023] Figure 2 Aberration-corrected transmission electron microscope AC-TEM of the few-layer carbon-coated titanium nitride substrate loaded with Pt single atoms prepared in Example 1;
[0024] Figure 3 HER performance and Pt mass activity (0.5M H2SO4) of the carbon film prepared in Example 1, titanium nitride composites with different thickness carbon layers loaded with Pt single atoms on the Ti-based electrode; among them, a is the linear sweep voltammetry curve (LSV) of various electrodes; b are the Pt mass activities of the electrodes at overpotentials of 50 mV and 100 mV respectively. Detailed Description of the Invention
[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, but 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] The selection of acid-resistant substrate materials is crucial for the preparation of carbon-supported single-atom electrodes. Metal titanium (Ti) and its nitride (TiN) have good acid resistance and are therefore widely used in proton exchange membrane water electrolysis technology as conductive electrodes. Therefore, titanium can be directly selected as the substrate material for carbon-supported single-atom catalysts. The present invention can prepare monolayer graphene films coated with titanium nitride, single-layer graphene-coated titanium nitride nanowires, single-layer graphene-coated titanium nitride nanorods, multi-layer graphene-coated titanium nitride nanowires, and multi-layer graphene-coated titanium nitride nanorods as metal single-atom carbon carriers by one-step high-temperature pyrolysis.
[0027] Example
[0028] A preparation method of a Ti-based electrode with controllable carbon layer-loaded single atoms includes the following steps:
[0029] 1) Place 1-10 g of solid-phase carbon source (melamine, dicyandiamide, urea, guanidine hydrochloride) and acid-treated flaky, reticular, etc. Ti substrates at the inlet of the tube furnace and the exact center of the heating zone respectively.
[0030] 2) Introduce inert gas (argon or nitrogen) and a certain proportion of hydrogen (hydrogen volume ratio: 0-100%), heat the tube furnace to 600-1200 °C, and maintain for 0-300 min. After natural cooling, a carbon-coated titanium-based material is obtained.
[0031] Figure 1 a NC@TiN film: 1 g of melamine is placed at the inlet of the tube furnace, the Ti sheet is placed at the exact center of the heating zone, heated to 900 °C at 5 °C / min, kept at a constant temperature for 1 min, and then cooled naturally, 10% H2.
[0032] Figure 1 b NC@TiN nanorods: 2 g of melamine is placed at the inlet of the tube furnace, the Ti sheet is placed at the exact center of the heating zone, heated to 500 °C at 5 °C / min, kept at a constant temperature for 60 min, then heated to 900 °C, kept at a constant temperature for 1 min, and then cooled naturally, 10% H2.
[0033] Figure 1 c NC@TiN nanowires: 1 g of melamine is placed at the inlet of the tube furnace, the Ti sheet is placed at the exact center of the heating zone, heated to 500 °C at 5 °C / min, kept at a constant temperature for 60 min, then heated to 900 °C, kept at a constant temperature for 1 min, and then cooled naturally, 10% H2.
[0034] Figure 1NC@TiN nanowires with different carbon thicknesses: Place 1 g of melamine at the inlet of the tube furnace, place the Ti sheet in the exact center of the heating zone, heat up to 500 °C at a rate of 5 °C / min, keep the temperature constant for 60 min, then heat up to 900 °C, and the constant temperature times are: 1 min, 10 min, 30 min, 60 min in sequence, cool down naturally, 10% H2.
[0035] 3) The titanium-based material obtained in step 2 is loaded with single-atom monolayer, few-layer, and multi-layer carbon-coated titanium-based electrodes by post-deposition methods (electrochemical deposition method and atomic layer deposition method). The single-atom species include but are not limited to platinum group metals (Pt / Ir / Ru / Rh / Pd / Os). Multiple single atoms can be deposited in one step or step by step to achieve low, medium, and high entropy single-atom loading on the single-layer carbon carrier.
[0036] 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, and 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 (potential range: -4 V to 4 V vs. RHE, sweep rate: 0 - 1000 mV / s, number of cycles: 0 - 10000 cycles).
[0037] Atomic layer deposition method: Taking Pt as an example, the Pt source is trimethylmethylcyclopentadienylplatinum ((MeCp)Pt(Me)3) and 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.
[0038] NC@TiN: No Pt is deposited.
[0039] Pt-NC@TiN: Directly heat up to 900 degrees in one step (all parameters for depositing Pt are the same).
[0040] Pt-NC(10nm)@TiN: After keeping the temperature constant at 500 degrees for 1 hour, heat up to 900 degrees, and keep the temperature constant for 60 minutes.
[0041] Pt-NC(1nm)@TiN: The same as above, keep the temperature constant for 1 minute.
[0042] 20 wt% Pt / C: Commercial product.
[0043] Figure 2The aberration-corrected electron microscopy results show that there is an amorphous carbon coating layer at the edge of the TiN nanowire, with a thickness within 1 nm. There are atom-sized bright spots loaded on it, which are atomically dispersed Pt single atoms (indicated by the red arrow).
[0044] Figure 3 a shows the linear sweep voltammetry (LSV) curves of various electrodes. The LSV curve of the Pt single atom-loaded 1 nm carbon-coated TiN nanowire (Pt-C(1 nm) / TiN nanowire) shows that at the same current density, the overpotential is the lowest (-100 mA / cm 2 , η = 69 mV vs RHE); Figure 3 b shows the Pt mass activities of the electrodes at overpotentials of 50 mV and 100 mV respectively. The results show that the Pt-C(1 nm) / TiN nanowire with the thinnest carbon layer loading has the highest Pt mass activity, reaching 35.3 A / mg Pt @50 mV and 153.1 A / mg Pt @100 mV.
[0045] In summary, the present invention selects an acid-resistant substrate material to prepare an electrode with carbon-supported single atoms. Through solutions such as optimizing the catalytic material, improving the growth conditions, and increasing the utilization rate of noble metal atoms, it is expected to achieve the uniform distribution and efficient utilization of noble metal atoms on monolayer graphene, and design and prepare a high-performance single-atom electrolyzed water catalyst.
[0046] 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-limiting. 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.
[0047] 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 preparation method of a titanium-based electrode with single atoms supported by a controllable carbon layer, characterized in that, It includes the following steps: (1) Place the solid-phase carbon source and the acid-treated titanium substrate at the inlet of the tubular furnace and the heating zone respectively; (2) Introduce inert gas and hydrogen in a certain proportion, heat the tubular furnace to 600 - 1200 °C, and maintain for 0 - 300 min; after natural cooling, a carbon-coated titanium-based material is obtained; (3) Load the single-atom monolayer, few-layer and multi-layer carbon-coated titanium-based electrodes on the carbon-coated titanium-based material by post-deposition method.
2. The preparation method of the titanium-based electrode with single atoms supported by a controllable carbon layer according to claim 1, wherein, In step (1), the solid-phase carbon source is melamine, dicyandiamide, urea or guanidine hydrochloride.
3. The preparation method of the titanium-based electrode with single atoms supported by a controllable carbon layer according to claim 1, characterized in that, In step (2), the inert gas is argon or nitrogen; the volume ratio of hydrogen is 0 - 100%.
4. The preparation method of the titanium-based electrode with single atoms supported on a controllable carbon layer according to claim 1, characterized in that, In step (3), the post-deposition method is electrochemical deposition method or atomic layer deposition method; it can realize one-step or step-by-step deposition of various single atoms, and realize the loading of low, medium and high entropy single atoms on the single-layer carbon carrier.
5. The preparation method of the titanium-based electrode with single atoms supported by a controllable carbon layer according to claim 1, characterized in that, In step (3), the single-atom species includes platinum group metals Pt / Ir / Ru / Rh / Pd / Os.