Synthesis method of NiFe layered double hydroxide Pt-based catalyst
By introducing NiFe layered double hydroxide cocatalyst into the Pt-based catalyst, a Pt/C-NiFe-LDH catalyst with significantly improved stability and activity in the acid-base environment was prepared, which solved the problem of poor stability of the existing Pt-based catalysts in the acid-base environment.
Patent Information
- Application Number
- CN202411737030.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-29
- Publication Date
- 2025-03-04
AI Technical Summary
The existing Pt-based catalysts have poor stability in acid-base environments and are difficult to maintain efficient catalytic activity in different environments.
The Pt/C-NiFe-LDH catalyst was prepared by a specific synthetic method using NiFe layered dihydroxide as a cocatalyst, and the stability of the catalyst was enhanced by the hydroxyl component of the layered dihydroxide.
In acidic and alkaline environments, the methanol oxidation activity and stability of Pt/C-NiFe-LDH catalysts are significantly improved, which is much higher than that of commercial Pt/C catalysts, solving the problem of poor stability.
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Figure CN119553312A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the technical field of Pt-based catalyst synthesis, in particular to a method for synthesizing a NiFe layered double hydroxide Pt-based catalyst. Background Art
[0002] Most of the current research is to introduce other metals to form alloys with Pt, or to add transition metal oxides, sulfides, nitrides, etc. These transition metal complexes can activate water molecules at a lower potential and accelerate H 2 The decomposition of O produces abundant hydroxyl components to participate in the reaction and removes CO-like intermediates chemically adsorbed on the active sites of Pt nanoparticles, thereby releasing more active sites to participate in the reaction and increasing the utilization rate of precious metals.
[0003] However, the Pt-based catalyst prepared by the above method has poor stability in an acidic or alkaline environment. Therefore, we provide a method for synthesizing a NiFe layered double hydroxide Pt-based catalyst. Summary of the invention
[0004] The object of the present invention is to provide a method for synthesizing a NiFe layered double hydroxide Pt-based catalyst to solve the problem that the Pt-based catalyst prepared by the existing method proposed in the above background technology has poor stability in an acidic or alkaline environment.
[0005] To achieve the above object, the present invention provides the following technical solution: a NiFe layered double hydroxide Pt-based catalyst, comprising the following steps: S1: 0.06mmol sodium dodecyl sulfate, 0.1g commercial carbon black, 0.8g urea and a certain proportion of nickel nitrate hexahydrate and iron nitrate nonahydrate were dissolved in a mixed solution, and after uniform dispersion and stirring, the solution was transferred to a high-pressure reactor. After the reaction was completed, the solution was further centrifuged, washed with ethanol and water respectively, and dried in an oven at 60°C for 12h to obtain a C-NiFe-LDH composite carrier; S2: Dissolve 20 mg of C-NiFe-LDH composite carrier in 15 mL of ethylene glycol solution and disperse by ultrasonic for 30 min. Quickly add 0.525 mL of 0.0488 M H 2 PtCl 6 -EG solution and stirred for 3 hours, the pH value of the solution was adjusted to 12, and then nitrogen was introduced to saturate the solution, the solution was heated, and the pH value of the solution was adjusted to 3 after cooling, and then stirred for 12 hours, filtered, washed with ethanol and water, and dried in an oven at 60°C for 12 hours to obtain a Pt / C-NiFe-LDH catalyst.
[0006] Preferably, in S1, the ratio of nickel nitrate hexahydrate to iron nitrate nonahydrate is 1:1, 2:1 or 3:1.
[0007] Preferably, in S1, the mixed solution is prepared by mixing 8 mL of water and 25 mL of ethylene glycol.
[0008] Preferably, in S1, the dispersing and stirring process is performed by an ultrasonic disperser, and the stirring is continued for 30 minutes.
[0009] Preferably, in S1, the reaction temperature of the high-pressure reactor is 150° C. and the reaction time is 12 h.
[0010] Preferably, in S2, the pH value of the solution is increased by adding 1M NaOH-EG, and the PD value of the solution is reduced by adding 0.1M HNO 3 accomplish.
[0011] Preferably, in S2, the solution is heated by a microwave reactor for 60 seconds.
[0012] Compared with the prior art, the present invention has the following beneficial effects: The present invention introduces a layered double hydroxide rich in hydroxyl groups as a co-catalyst for Pt nanoparticles. The electrochemical test results show that the Pt / C-NiFe-LDH not only exhibits good methanol oxidation activity and catalytic stability in an alkaline environment, but also in an acidic environment, the methanol oxidation activity and stability of Pt / C-NiFe-LDH are much higher than those of commercial Pt / C catalysts, thereby solving the problem of poor stability of Pt-based catalysts prepared by existing methods in acidic and alkaline environments. BRIEF DESCRIPTION OF THE DRAWINGS
[0013] Figure 1 The Pt / C-NiFe-LDH catalysts with different Ni / Fe ratios of the present invention were heated to 0.5 MH 2 SO 4 +1.0 MCH 3 Schematic diagram of CV curve (a), mass activity curve (b) and CA curve (c) in OH solution; Figure 2 The Pt / C-NiFe-LDH of the present invention and the commercial Pt / C catalyst were reacted in 1.0 M KOH + 1.0 M CH 3 Schematic diagram of mass activity curve (a) and CA curve (b) in OH solution; Figure 3 The Pt / C-NiFe-LDH of the present invention and the commercial Pt / C catalyst were subjected to 0.5 MH 2 SO 4 +1.0 M CH3 Schematic diagram of CV curve (a), mass activity curve (b) and CA curve (c) in OH solution. DETAILED DESCRIPTION
[0014] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.
[0015] See also Figure 1-3 , an embodiment provided by the present invention: a NiFe layered double hydroxide Pt-based catalyst, comprising the following steps: S1: 0.06mmol sodium dodecyl sulfate, 0.1g commercial carbon black, 0.8g urea and a certain proportion of nickel nitrate hexahydrate and iron nitrate nonahydrate were dissolved in a mixed solution, and after uniform dispersion and stirring, the solution was transferred to a high-pressure reactor. After the reaction was completed, the solution was further centrifuged, washed with ethanol and water respectively, and dried in an oven at 60°C for 12h to obtain a C-NiFe-LDH composite carrier; S2: Dissolve 20 mg of C-NiFe-LDH composite carrier in 15 mL of ethylene glycol solution and disperse by ultrasonic for 30 min. Quickly add 0.525 mL of 0.0488 M H 2 PtCl 6 -EG solution and stirred for 3 hours, the pH value of the solution was adjusted to 12, and then nitrogen was introduced to saturate the solution, the solution was heated, and the pH value of the solution was adjusted to 3 after cooling, and then stirred for 12 hours, filtered, washed with ethanol and water, and dried in an oven at 60°C for 12 hours to obtain a Pt / C-NiFe-LDH catalyst.
[0016] Furthermore, in S1, the ratio of nickel nitrate hexahydrate to iron nitrate nonahydrate is 1:1, 2:1 or 3:1.
[0017] Further, in S1, the mixed solution is prepared by mixing 8 mL of water and 25 mL of ethylene glycol.
[0018] Furthermore, in S1, the dispersion stirring process is performed by an ultrasonic disperser, and the stirring is continued for 30 minutes.
[0019] Furthermore, in S1, the reaction temperature of the high-pressure reactor is 150° C., and the reaction time is 12 h.
[0020] Furthermore, in S2, the pH value of the solution was increased by adding 1 M NaOH-EG, and the PD value of the solution was reduced by adding 0.1 M HNO 3 accomplish.
[0021] Further, in S2, the solution is heated by a microwave reactor, and the heating time is 60 s.
[0022] Experimental results: By the attached Figure 1 It can be seen from the comparison that when the Ni / Fe ratio is 2:1, the methanol oxidation activity and catalytic stability of the catalyst are the best; By the attached Figure 2 and attached Figure 3 It can be seen that the synthesized Pt / C-NiFe-LDH catalyst exhibits good catalytic activity in both acidic and alkaline environments.
[0023] It will be apparent to those skilled in the art that the invention is not limited to the details of the exemplary embodiments described above and that the invention can be implemented in other specific forms without departing from the spirit or essential features of the invention. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is intended that all variations falling within the meaning and scope of the equivalent elements of the claims be included in the invention. Any reference numeral in a claim should not be considered as limiting the claim to which it relates.
Claims
1. A NiFe layered double hydroxide Pt-based catalyst, characterized in that: The following steps are involved: S1: 0.06mmol sodium dodecyl sulfate, 0.1g commercial carbon black, 0.8g urea and a certain proportion of nickel nitrate hexahydrate and iron nitrate nonahydrate were dissolved in a mixed solution, and after uniform dispersion and stirring, the solution was transferred to a high-pressure reactor. After the reaction was completed, the solution was further centrifuged, washed with ethanol and water respectively, and dried in an oven at 60°C for 12h to obtain a C-NiFe-LDH composite carrier; S2: Take 20 mg of C-NiFe-LDH composite carrier and dissolve it in 15 mL of ethylene glycol solution, and ultrasonically disperse it for 30 minutes, quickly add 0.525 mL of 0.0488 M H2PtCl6-EG solution, and stir for 3 hours, adjust the pH value of the solution to 12, then introduce nitrogen to saturate, heat the solution, adjust the pH value of the solution to 3 after cooling, and continue stirring for 12 hours, filter, wash with ethanol and water, and dry in an oven at 60°C for 12 hours to obtain Pt / C-NiFe-LDH catalyst.
2. A NiFe layered double hydroxide Pt-based catalyst according to claim 1, characterized in that: In S1, the ratio of nickel nitrate hexahydrate to iron nitrate nonahydrate is 1:1, 2:1 or 3:
1.
3. A NiFe layered double hydroxide Pt-based catalyst according to claim 2, characterized in that: In S1, the mixed solution is prepared by mixing 8 mL of water and 25 mL of ethylene glycol.
4. A NiFe layered double hydroxide Pt-based catalyst according to claim 3, characterized in that: In S1, the dispersion and stirring process is performed by an ultrasonic disperser, and the stirring is continued for 30 minutes.
5. A NiFe layered double hydroxide Pt-based catalyst according to claim 4, characterized in that: In S1, the reaction temperature of the high-pressure reactor is 150° C. and the reaction time is 12 h.
6. A NiFe layered double hydroxide Pt-based catalyst according to claim 5, characterized in that: In S2, the pH value of the solution is increased by adding 1M NaOH-EG, and the PD value of the solution is reduced by adding 0.1M HNO3.
7. A NiFe layered double hydroxide Pt-based catalyst according to claim 6, characterized in that: In S2, the solution is heated by a microwave reactor for 60 seconds.