Method for preparing ru / mn oxide electrocatalyst by ar plasma treatment

Abstract

The application discloses a method for preparing Ru / Mn oxide electrocatalyst by Ar plasma treatment, and is specifically implemented according to the following steps: step 1, uniformly depositing MnO2 as a substrate on carbon paper by an anodic electrodeposition method; step 2, manufacturing defects and oxygen vacancies on the surface of the MnO2 substrate by an Ar plasma treatment method; and step 3, loading Ru atoms on the surface of the MnO2 with the defects and the oxygen vacancies by an immersion method, and anchoring by annealing to obtain the Ru / Mn oxide electrocatalyst. The method for preparing the Ru / Mn oxide electrocatalyst has a lower Ru noble metal consumption, higher activity, and the catalyst also has good stability, and can stably electrolyze water to generate oxygen for more than 400 hours under an acidic condition.

Description

Technical Field

[0001] This invention belongs to the field of catalyst preparation technology, and relates to a method for preparing Ru / Mn oxide electrocatalysts by Ar plasma treatment. Background Technology

[0002] Electrocatalytic water electrolysis for hydrogen production, powered by renewable energy sources such as solar, tidal, and wind power, is a clean and high-purity hydrogen production technology. Among these, acidic water electrolysis technology offers advantages such as high current density, fast response time, and high hydrogen purity, making it a promising candidate for industrial application. However, the slow four-electron reaction in the acidic oxygen evolution reaction (OER) severely limits the efficiency of acidic water electrolysis. Therefore, there is an urgent need to develop highly active, structurally stable, and low-cost acidic water electrolysis catalysts. Currently, most highly active acidic OER catalysts are Ir / Ru-based noble metal catalysts. For noble metal catalysts, reducing the amount of noble metal used while maintaining high catalytic performance and stability remains a significant challenge. Loading a small amount of noble metal catalyst onto a transition metal oxide substrate to improve the specific activity of the noble metal has a crucial practical driving force for acidic water electrolysis for hydrogen production.

[0003] Currently, most noble metal catalysts for acidic anode oxygen evolution reaction (OER) employ a hydrothermal method. This involves first dissolving a noble metal salt in ethanol or water and mixing it with other non-noble metal solutions. The mixture is then subjected to high-temperature hydrothermal treatment to obtain a noble metal-based acidic OER catalyst powder. Finally, this catalyst powder is loaded onto the electrode via spraying or drop-coating for performance testing. However, this method results in low utilization of noble metals, leading to typically low catalyst activity and significantly increasing preparation costs. Furthermore, the catalyst is unstable and prone to detaching from the electrode during use, severely hindering its application in high-quality integrated devices. Summary of the Invention

[0004] The purpose of this invention is to provide a method for preparing Ru / Mn oxide electrocatalysts by Ar plasma treatment, which solves the problems of low catalytic activity, easy electrode detachment, and poor stability in the prior art.

[0005] The technical solution adopted in this invention is a method for preparing Ru / Mn oxide electrocatalysts by Ar plasma treatment, specifically implemented according to the following steps:

[0006] Step 1: Uniformly deposit MnO2 as a substrate on carbon paper using anodic electrodeposition.

[0007] Step 2: Defects and oxygen vacancies are created on the surface of the MnO2 substrate using Ar plasma treatment.

[0008] Step 3: Load Ru atoms onto the defective MnO2 surface by impregnation and anchor them by annealing to obtain Ru / Mn oxide electrocatalyst.

[0009] The invention is further characterized by:

[0010] Step 1 is implemented in the following steps:

[0011] Step 1.1: Place the carbon paper in a mixed solution of concentrated sulfuric acid and concentrated nitric acid for acid treatment, then wash and dry it for later use;

[0012] Step 1.2: Place the cleaned and dried carbon paper in the electrolyte and use it as the working electrode in the three-electrode system to electrochemically deposit MnO2;

[0013] Step 1.3: Dry the obtained MnO2 electrode thoroughly at 50℃~70℃.

[0014] In step 1.1, the ratio of concentrated sulfuric acid to concentrated nitric acid is 3:1 to 1:3, the carbon paper size is 1cm×1cm×0.3cm, and the acid treatment time is 3min to 15min.

[0015] In step 1.2, the electrolyte is a mixed solution of Na2SO4 and Mn(CH3COO)2, a carbon rod is used as the counter electrode, an Ag / AgCl electrode is used as the reference electrode, the deposition potential is +0.3V to +0.8V vs SCE, and the deposition time is 3min to 30min.

[0016] Step 2 specifically involves placing the MnO2 substrate in a plasma cleaner with a power setting of 50W to 300W, a pressure setting of 40Pa to 100Pa, and an argon flow rate of 1cc / min to 10cc / min for plasma treatment for 1 to 10 minutes.

[0017] Step 3 is implemented in the following steps:

[0018] Step 3.1: Immerse the defective MnO2 substrate obtained in Step 2 in a 5mM~20mM RuCl3 solution for 30min~120min, while simultaneously heating in a water bath to keep the RuCl3 solution at 25℃~85℃;

[0019] Step 3.2: Place the soaked MnO2 substrate in a muffle furnace for annealing and anchoring.

[0020] The specific annealing anchoring parameters in step 3.2 are: annealing temperature 200℃~300℃, annealing time 1h~3h, and heating and cooling rates of 5℃ / min~10℃ / min.

[0021] The beneficial effects of this invention are:

[0022] (1) The method for preparing Ru / Mn oxide electrocatalyst by Ar plasma treatment of the present invention involves uniformly depositing MnO2 on the surface of carbon paper as a substrate by electrodeposition. The MnO2 prepared in this process has a loose and porous structure and good bonding force with the carbon paper, which is not easy to fall off, thus providing a prerequisite for the excellent stability of the subsequent electrode in the oxygen evolution reaction.

[0023] (2) The method for preparing Ru / Mn oxide electrocatalyst by Ar plasma treatment of the present invention uses Ar plasma treatment. The plasma cleaner excites Ar into a plasma state and impacts the surface of MnO2 substrate, leaving physical defects and oxygen vacancies. This process can provide sufficient sites for subsequent Ru atom loading and effectively avoid Ru atom aggregation.

[0024] (3) The method for preparing Ru / Mn oxide electrocatalyst by Ar plasma treatment of the present invention loads Ru atoms by impregnation. During this process, Ru atoms will be preferentially loaded at the defects on the substrate surface. At the same time, oxygen vacancies can effectively improve the electronic structure around Ru, optimize the adsorption capacity of Ru for catalytic intermediates, and inhibit their peroxidation, which greatly improves the activity and stability of the catalyst.

[0025] (4) The method for preparing Ru / Mn oxide electrocatalyst by Ar plasma treatment of the present invention has extremely high catalytic activity and low Ru precious metal content. At the same time, the catalyst also has good stability and can stably electrolyze water and oxygen evolution reaction for more than 400 hours under acidic conditions. Therefore, it can be applied to the electrocatalytic decomposition of water and oxygen evolution reaction. Attached Figure Description

[0026] Figure 1 This is a flowchart of the method for preparing Ru / Mn oxide electrocatalysts by Ar plasma treatment according to the present invention;

[0027] Figure 2 This is a scanning electron microscope image of the MnO2 substrate prepared in the method for preparing Ru / Mn oxide electrocatalysts of the present invention;

[0028] Figure 3 This is a scanning electron microscope image of the Ru / Mn oxide electrocatalyst prepared in the method for preparing Ru / Mn oxide electrocatalyst of the present invention;

[0029] Figure 4 This is a Lorentz transmission electron microscope image of the MnO2 substrate prepared in the method for preparing Ru / Mn oxide electrocatalysts of this invention;

[0030] Figure 5This is a Lorentz transmission electron microscope image of the MnO2-P catalyst prepared in the method for preparing Ru / Mn oxide electrocatalysts of this invention.

[0031] Figure 6 This is a Lorentz transmission electron microscope image of the Ru / Mn oxide electrocatalyst prepared in the method for preparing Ru / Mn oxide electrocatalyst of the present invention;

[0032] Figure 7 This is a graph showing the oxygen evolution reaction polarization curve of the Ru / Mn oxide electrocatalyst prepared by linear sweep voltammetry in the method for preparing Ru / Mn oxide electrocatalysts of this invention.

[0033] Figure 8 This is the stability curve of the Ru / Mn oxide electrocatalyst obtained in the method for preparing Ru / Mn oxide electrocatalysts of the present invention for the continuous oxygen evolution reaction. Detailed Implementation

[0034] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0035] The present invention describes a method for preparing Ru / Mn oxide electrocatalysts by Ar plasma treatment, as follows: Figure 1 As shown, please follow these steps:

[0036] Step 1: Uniformly deposit MnO2 as a substrate on carbon paper using anodic electrodeposition.

[0037] Step 1 is implemented in the following steps:

[0038] Step 1.1: Place the carbon paper in a mixed solution of concentrated sulfuric acid and concentrated nitric acid for acid treatment, then wash and dry it for later use;

[0039] Step 1.2: Place the cleaned and dried carbon paper in the electrolyte and use it as the working electrode in the three-electrode system to electrochemically deposit MnO2;

[0040] Step 1.3: Dry the obtained MnO2 electrode thoroughly at 50℃~70℃;

[0041] In step 1.1, the ratio of concentrated sulfuric acid to concentrated nitric acid is 3:1 to 1:3, the carbon paper size is 1cm×1cm×0.3cm, and the acid treatment time is 3min to 15min.

[0042] In step 1.2, the electrolyte is a mixed solution of Na2SO4 and Mn(CH3COO)2, a carbon rod is used as the counter electrode, an Ag / AgCl electrode is used as the reference electrode, the deposition potential is +0.3V to +0.8V vs SCE, and the deposition time is 3min to 30min.

[0043] Step 2: Defects and oxygen vacancies are created on the surface of the MnO2 substrate using Ar plasma treatment.

[0044] Step 2 is as follows: Place the MnO2 substrate in a plasma cleaner, set the power to 50W to 300W, the pressure to 40Pa to 100Pa, and the argon flow rate to 1cc / min to 10cc / min for plasma treatment, and the treatment time to 1min to 10min.

[0045] Step 3: Load Ru atoms onto the MnO2 surface with defects and oxygen vacancies by impregnation and anchor them by annealing to obtain Ru / Mn oxide electrocatalyst;

[0046] Step 3 is implemented in the following steps:

[0047] Step 3.1: Immerse the defective MnO2 substrate obtained in Step 2 in a 5mM to 20mM RuCl3 solution for 30 min to 120 min, while simultaneously heating in a water bath to maintain the RuCl3 solution at 25℃ to 85℃.

[0048] Step 3.2: Place the soaked MnO2 substrate in a muffle furnace for annealing and anchoring;

[0049] The specific annealing anchoring parameters in step 3.2 are: annealing temperature 200℃~300℃, annealing time 1h~3h, and heating and cooling rates of 5℃ / min~10℃ / min.

[0050] Example 1

[0051] The present invention describes a method for preparing Ru / Mn oxide electrocatalysts by Ar plasma treatment, as follows: Figure 1 As shown, please follow these steps:

[0052] Step 1: Uniformly deposit MnO2 as a substrate on carbon paper using anodic electrodeposition.

[0053] Step 1 is implemented in the following steps:

[0054] Step 1.1: Place the carbon paper in a mixed solution of concentrated sulfuric acid and concentrated nitric acid for acid treatment, then wash and dry it for later use;

[0055] Step 1.2: Place the cleaned and dried carbon paper in the electrolyte and use it as the working electrode in the three-electrode system to electrochemically deposit MnO2;

[0056] Step 1.3: Dry the obtained MnO2 electrode thoroughly at 50°C;

[0057] In step 1.1, the ratio of concentrated sulfuric acid to concentrated nitric acid is 3:1, the carbon paper size is 1cm×1cm×0.3cm, and the acid treatment time is 3min.

[0058] In step 1.2, the electrolyte is a mixed solution of Na2SO4 and Mn(CH3COO)2, a carbon rod is used as the counter electrode, an Ag / AgCl electrode is used as the reference electrode, the deposition potential is +0.3V vs SCE, and the deposition time is 3min.

[0059] Step 2: Defects and oxygen vacancies are created on the surface of the MnO2 substrate using Ar plasma treatment.

[0060] Step 2 specifically involves placing the MnO2 substrate in a plasma cleaner with a power setting of 50W, a pressure setting of 40Pa, and an argon flow rate of 1cc / min for plasma treatment for 1 minute.

[0061] Step 3: Load Ru atoms onto the MnO2 surface with defects and oxygen vacancies by impregnation and anchor them by annealing to obtain Ru / Mn oxide electrocatalyst;

[0062] Step 3 is implemented in the following steps:

[0063] Step 3.1: Immerse the defective MnO2 substrate obtained in Step 2 in 5 mL of RuCl3 solution for 30 min, while simultaneously heating in a water bath to keep the RuCl3 solution at 25 °C.

[0064] Step 3.2: Place the soaked MnO2 substrate in a muffle furnace for annealing and anchoring;

[0065] The specific annealing anchoring parameters in step 3.2 are: annealing temperature 200℃, annealing time 1h, and heating and cooling rates of 5℃ / min.

[0066] Example 2

[0067] The present invention describes a method for preparing Ru / Mn oxide electrocatalysts by Ar plasma treatment, as follows: Figure 1 As shown, please follow these steps:

[0068] Step 1: Uniformly deposit MnO2 as a substrate on carbon paper using anodic electrodeposition.

[0069] Step 1 is implemented in the following steps:

[0070] Step 1.1: Place the carbon paper in a mixed solution of concentrated sulfuric acid and concentrated nitric acid for acid treatment, then wash and dry it for later use;

[0071] Step 1.2: Place the cleaned and dried carbon paper in the electrolyte and use it as the working electrode in the three-electrode system to electrochemically deposit MnO2;

[0072] Step 1.3: Dry the obtained MnO2 electrode thoroughly at 60℃;

[0073] In step 1.1, the ratio of concentrated sulfuric acid to concentrated nitric acid is 3:1, the carbon paper size is 1cm×1cm×0.3cm, and the acid treatment time is 10min.

[0074] In step 1.2, the electrolyte is a mixed solution of Na2SO4 and Mn(CH3COO)2, a carbon rod is used as the counter electrode, an Ag / AgCl electrode is used as the reference electrode, the deposition potential is +0.5V vs SCE, and the deposition time is 15min.

[0075] Step 2: Defects and oxygen vacancies are created on the surface of the MnO2 substrate using Ar plasma treatment.

[0076] Step 2 specifically involves placing the MnO2 substrate in a plasma cleaner with a power setting of 100W, a pressure setting of 80Pa, and an argon flow rate of 5cc / min for plasma treatment for 5 minutes.

[0077] Step 3: Load Ru atoms onto the MnO2 surface with defects and oxygen vacancies by impregnation and anchor them by annealing to obtain Ru / Mn oxide electrocatalyst;

[0078] Step 3 is implemented in the following steps:

[0079] Step 3.1: Immerse the defective MnO2 substrate obtained in Step 2 in 10mM RuCl3 solution for 60min, while heating in a water bath to keep the RuCl3 solution at 65℃.

[0080] Step 3.2: Place the soaked MnO2 substrate in a muffle furnace for annealing and anchoring;

[0081] The specific annealing anchoring parameters in step 3.2 are: annealing temperature 250℃, annealing time 2h, and heating and cooling rates of 8℃ / min.

[0082] Example 3

[0083] The present invention describes a method for preparing Ru / Mn oxide electrocatalysts by Ar plasma treatment, as follows: Figure 1 As shown, please follow these steps:

[0084] Step 1: Uniformly deposit MnO2 as a substrate on carbon paper using anodic electrodeposition.

[0085] Step 1 is implemented in the following steps:

[0086] Step 1.1: Place the carbon paper in a mixed solution of concentrated sulfuric acid and concentrated nitric acid for acid treatment, then wash and dry it for later use;

[0087] Step 1.2: Place the cleaned and dried carbon paper in the electrolyte and use it as the working electrode in the three-electrode system to electrochemically deposit MnO2;

[0088] Step 1.3: Dry the obtained MnO2 electrode thoroughly at 70℃;

[0089] In step 1.1, the ratio of concentrated sulfuric acid to concentrated nitric acid is 1:3, the carbon paper size is 1cm×1cm×0.3cm, and the acid treatment time is 15min.

[0090] In step 1.2, the electrolyte is a mixed solution of Na2SO4 and Mn(CH3COO)2, a carbon rod is used as the counter electrode, an Ag / AgCl electrode is used as the reference electrode, the deposition potential is +0.8V vs SCE, and the deposition time is 30min.

[0091] Step 2: Defects and oxygen vacancies are created on the surface of the MnO2 substrate using Ar plasma treatment.

[0092] Step 2 is as follows: Place the MnO2 substrate in a plasma cleaner with a power of 300W, a pressure of 100Pa, and an argon flow rate of 10cc / min for plasma treatment for 10 minutes.

[0093] Step 3: Load Ru atoms onto the MnO2 surface with defects and oxygen vacancies by impregnation and anchor them by annealing to obtain Ru / Mn oxide electrocatalyst;

[0094] Step 3 is implemented in the following steps:

[0095] Step 3.1: Immerse the defective MnO2 substrate obtained in Step 2 in 20 mL of RuCl3 solution for 120 min, while simultaneously heating in a water bath to keep the RuCl3 solution at 85 °C.

[0096] Step 3.2: Place the soaked MnO2 substrate in a muffle furnace for annealing and anchoring;

[0097] The specific annealing anchoring parameters in step 3.2 are: annealing temperature 300℃, annealing time 3h, and heating and cooling rates of 10℃ / min.

[0098] The present invention provides a method for preparing Ru / Mn oxide electrocatalysts, from... Figure 2 and Figure 4 It can be seen that MnO2 exists in the form of uniformly distributed, loosely porous nanoflowers; from Figure 3 and Figure 6 As can be seen, Ru is uniformly distributed on the MnO2 surface in the form of nanoparticles, which exposes more active sites at the catalytic interface for the limited Ru atoms, effectively improving the utilization rate of Ru atoms and their mass-to-specific activity; from Figure 5 It can be seen that MnO2 develops physical defects after plasma treatment; from Figure 7 and Figure 8 As can be seen, MnO2 after plasma treatment can better support and anchor Ru atoms, which greatly improves the activity and stability of the catalyst.

[0099] In summary, the method for preparing Ru / Mn oxide electrocatalysts of the present invention yields Ru / Mn oxide electrocatalysts with low Ru noble metal content, high activity, and good stability, capable of stably performing the oxygen evolution reaction of water electrolysis for more than 400 hours under acidic conditions.

Claims

1. A method for preparing Ru / Mn oxide electrocatalysts by Ar plasma treatment, characterized in that, The specific steps are as follows: Step 1: Uniformly deposit MnO2 as a substrate on carbon paper using anodic electrodeposition. Step 2: Create defects and oxygen vacancies on the surface of MnO2 substrate by Ar plasma treatment. Specifically, place the MnO2 substrate in a plasma cleaner with a power of 50W~300W, a pressure of 40Pa~100Pa, and an argon flow rate of 1cc / min~10cc / min for plasma treatment for 1min~10min. Step 3: Load Ru atoms onto the MnO2 surface containing defects and oxygen vacancies using an impregnation method, and then anchor them through annealing to obtain a Ru / Mn oxide electrocatalyst. This is carried out according to the following steps: Step 3.1: Immerse the defective MnO2 substrate obtained in Step 2 in a 5mM~20mM RuCl3 solution for 30min~120min, while heating in a water bath to keep the RuCl3 solution at 25℃~85℃. Step 3.2: Place the soaked MnO2 substrate in a muffle furnace for annealing and anchoring. The specific annealing and anchoring parameters are: annealing temperature 200℃~300℃, annealing time 1h~3h, and heating and cooling rates of 5℃ / min~10℃ / min, to obtain Ru / Mn oxide electrocatalyst.

2. The method for preparing Ru / Mn oxide electrocatalyst according to claim 1, characterized in that, Step 1 is implemented in the following steps: Step 1.1: Place the carbon paper in a mixed solution of concentrated sulfuric acid and concentrated nitric acid for acid treatment, then wash and dry it for later use; Step 1.2: Place the cleaned and dried carbon paper in the electrolyte and use it as the working electrode in the three-electrode system to electrochemically deposit MnO2; Step 1.3: Dry the obtained MnO2 electrode thoroughly at 50℃~70℃.

3. The method for preparing Ru / Mn oxide electrocatalyst according to claim 2, characterized in that, In step 1.1, the ratio of concentrated sulfuric acid to concentrated nitric acid is 3:1 to 1:3, the carbon paper size is 1cm×1cm×0.3cm, and the acid treatment time is 3min to 15min.

4. The method for preparing Ru / Mn oxide electrocatalyst according to claim 2, characterized in that, In step 1.2, the electrolyte is a mixed solution of Na2SO4 and Mn(CH3COO)2, and the deposition time is 3 min to 30 min.

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