Carbon-supported ruthenium manganese oxide anodic oxygen evolution reaction catalyst, its preparation method and application

Abstract

This invention discloses a carbon-supported ruthenium manganese oxide anode oxygen evolution reaction catalyst, its preparation method, and its applications, including: preparing RuMnO x Precursor solution, carbon paper pre-cleaning, RuMnO x The precursor solution was dipped onto the surface of carbon paper, vacuum dried, and then oxidized and sintered in a muffle furnace to obtain carbon-supported ruthenium manganese oxide, thus yielding RuMnO in situ grown on the surface of carbon paper. x Catalyst; a three-electrode system was used, and chronoamperometry was employed to catalyze the in-situ growth of RuMnO on the surface of carbon paper. x The catalyst was activated under an activation voltage of no more than 1.1V vs. RHE to obtain the OER catalyst. This invention reveals that the catalyst can be activated under an activation voltage ≤ 1.1V vs. RHE, and the activated catalyst operates stably for 1500 hours in a constant current test, significantly improving the catalyst's activity and ultra-high stability. It has broad application prospects in acidic water electrolysis oxygen evolution reactions.

Description

Technical Field

[0001] This invention belongs to the field of electrochemical technology, specifically relating to carbon-supported ruthenium manganese oxide anodic oxygen evolution reaction catalyst, its preparation method, and its application. Background Technology

[0002] Proton exchange membrane electrolysis (PEMWE) is a clean and efficient hydrogen production technology, characterized by its compact structure, low impedance, and high current density. However, its anodic oxygen evolution reaction (OER) is a four-electron reaction process with slow reaction kinetics and a high overpotential, which has become a bottleneck for PEMWE development. Furthermore, the anode side of PEMWE is a strongly acidic and high-potential reaction environment, which has a strong corrosive effect on the catalyst, placing high demands on the activity and stability of the OER catalyst.

[0003] Currently, acidic OER catalysts mainly rely on noble metal Ru and Ir-based catalysts. Compared to Ir, Ru exhibits higher catalytic activity and lower cost. To achieve large-scale application of Ru-based catalysts, further improvements in catalyst activity and durability are needed. Furthermore, in highly corrosive environments, OER catalysts undergo surface ion dissolution-deposition, which, under specific conditions, leads to catalyst surface reconstruction and activation, significantly enhancing OER catalytic activity. However, the activation of Ru-based catalysts has not been extensively reported in the literature, and stability tests (at a constant current of 10 mA / cm²) are limited. 2 Or constant voltage test (10mA / cm) 2 The corresponding initial voltage value is basically no more than 50 hours, and its durability needs to be further improved. Summary of the Invention

[0004] To address the shortcomings of existing technologies, the main objective of this invention is to provide a method for preparing a carbon-supported ruthenium manganese oxide anolyte oxygen evolution reaction catalyst, through the in-situ growth of RuMnO4 on carbon paper (CFP). x It is obtained by activating the catalyst.

[0005] Another objective of this invention is to provide a carbon-supported ruthenium manganese oxide anode oxygen evolution reaction catalyst, which is obtained by the above preparation method. The catalyst surface undergoes dissolution-deposition, thereby achieving catalyst reconstruction and significantly improving catalyst activity.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] This invention provides a method for preparing a carbon-supported ruthenium manganese oxide anode oxygen evolution reaction catalyst, comprising the following steps:

[0008] Step 1: Preparation of RuMnO x Precursor solution;

[0009] Step 2: Carbon paper pre-cleaning, RuMnO x The precursor solution was dipped onto the surface of carbon paper, vacuum dried, and then oxidized and sintered in a muffle furnace to obtain carbon-supported ruthenium manganese oxide, thus yielding RuMnO in situ grown on the surface of carbon paper. x catalyst;

[0010] Step 3: The RuMnO grown in situ on the surface of carbon paper x The catalyst is electrochemically activated to obtain the OER catalyst;

[0011] The electrochemical activation process includes: using a three-electrode system, employing chronoamperometry (CA) to activate the RuMnO4 in situ grown on the surface of carbon paper. x The catalyst was activated under an activation voltage of no more than 1.1V vs. RHE.

[0012] Preferably, in step 1, the vacuum drying temperature is 40-70℃ and the time is 10-20 minutes.

[0013] Preferably, in step 1, the RuMnO x The preparation method of the precursor solution includes: mixing 138.5 mg MnCl2 precursor with 0.16 g polyvinylpyrrolidone (PVP), 145.2 mg RuCl3 solution, and 3 mL of ultrapure water, stirring overnight to form 3 mL of RuMnO. x The precursor mixture solution contains Ru and Mn in a 1:1 ratio, each with a concentration of 0.7 mmol.

[0014] Preferably, in step 2, after the 1×2cm carbon paper is cleaned and dried, it is placed in the RuMnO... x Immerse in the precursor solution until the surface is fully covered with RuMnO x After the precursor solution was prepared, the carbon paper was removed and vacuum dried in an oven at 70°C. The dried carbon paper was then placed in a muffle furnace for oxidation sintering in air at a temperature of 400°C. The muffle furnace was heated at a rate of 10°C / min for 3 hours, followed by natural cooling to obtain RuMnO2 grown in situ on the surface of the carbon paper. x catalyst.

[0015] Preferably, in step 3, the RuMnO x The electrochemical activation process of the catalyst includes: using a three-electrode system, with 0.5M H2SO4 solution or 0.1M HClO4 solution as the electrolyte, a carbon rod as the counter electrode, and a saturated calomel electrode as the reference electrode, and employing a chronoamperometry method to activate the RuMnO4 in situ grown on the surface of carbon paper. xThe catalyst was activated for 1-3 hours at an activation voltage not greater than 1.1V vs. RHE.

[0016] The present invention also provides a carbon-supported ruthenium manganese oxide anode oxygen evolution reaction catalyst, which is prepared by the aforementioned method for preparing the carbon-supported ruthenium manganese oxide anode oxygen evolution reaction catalyst.

[0017] The present invention also provides the application of the carbon-supported ruthenium manganese oxide anodic oxygen evolution reaction catalyst in the oxygen evolution reaction of acidic water electrolysis.

[0018] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0019] 1. This invention employs an in-situ growth method to directly fabricate electrodes for the oxygen evolution reaction in acidic water electrolysis, producing in-situ grown RuMnO. x In constant voltage tests at 1.4, 1.1, 0.8, and 0.5 V vs. RHE, it was found that the catalyst was activated at a voltage ≤ 1.1 V vs. RHE. This activation process was due to the Mn in the catalyst undergoing Mn oxidation at lower potential ranges (≤ 1.1 V vs. RHE). IV / Mn II The conversion of Mn II As the Mn in the catalyst is in a soluble ionic state, it dissolves, leading to surface structure collapse. Combined with ICP characterization results, it was found that the dissolution of both Mn and Ru was intensified. Since Ru is in a deposition range within this potential range, it redeposited on the surface after dissolution. Characterization tests revealed that the deposited surface exhibited higher adsorption of hydroxyl oxides (OH), thus facilitating OER and significantly improving catalyst activity.

[0020] 2. The OER catalyst of this invention exhibits significant catalyst dissolution during activation, but it can withstand a constant current (10 mA / cm²) in a 0.5 M H₂SO₄ electrolyte. 2 It has been running stably for 1500 hours in durability tests, demonstrating extremely high stability.

[0021] 3. In this invention, RuMnO is grown in situ on carbon paper. x The catalyst surface was activated to obtain a carbon-supported ruthenium manganese oxide anodic oxygen evolution reaction catalyst. During the activation process, Mn dissolved, causing the surface structure to collapse. The redeposition of Ru reconstituted the surface, which significantly improved the activity of the catalyst. Attached Figure Description

[0022] Figure 1 In the example, RuMnO x The OER activity after activation at (a) 1.4V; (b) 1.1V; (c) 0.8V; (d) 0.5V vs. RHE voltages.

[0023] Figure 2 In the example, RuMnO x Ion dissolution at (a) 1.4V; (b) 1.1V; (c) 0.8V; (d) 0.5V vs. RHE voltages.

[0024] Figure 3 In the example, RuMnO x O1s XPS activated at 0.5V, 0.8V, 1.1V, 1.4V vs. RHE voltages.

[0025] Figure 4 In the example, RuMnO x A graph showing the constant current test results for the catalyst. Detailed Implementation

[0026] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the described embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0027] The following examples illustrate a method for preparing a carbon-supported ruthenium manganese oxide anode oxygen evolution reaction catalyst, including:

[0028] Step 1: Preparation of RuMnO x The precursor solution contains Ru and Mn ion concentrations in a 1:1 ratio.

[0029] Step 2: Carbon paper pre-cleaning, RuMnO x The precursor solution was dipped onto the surface of carbon paper, vacuum dried at 40-70℃ for 10-20 min, and then oxidized and sintered in a muffle furnace to obtain carbon-supported ruthenium manganese oxide. The sintering temperature was 400℃, the heating rate of the muffle furnace was 10℃ / min, and after sintering for 3 h, it was allowed to cool naturally to obtain RuMnO in situ grown on the surface of carbon paper. x catalyst;

[0030] Step 3: Using a three-electrode system, with 0.5M H2SO4 solution as the electrolyte, a carbon rod as the counter electrode, and a saturated calomel electrode as the reference electrode, the RuMnO4 in situ grown on the carbon paper surface was subjected to chronoamperometry. x The catalyst was activated under an activation voltage of no more than 1.1 V vs. RHE to obtain the OER catalyst.

[0031] Example 1

[0032] The preparation of the carbon-supported ruthenium manganese oxide anode oxygen evolution reaction catalyst in this embodiment is carried out by the following steps:

[0033] 1. First, prepare a RuCl3 solution. Then, mix 138.5 mg of MnCl2 precursor with 0.16 g of PVP, 145.2 mg of RuCl3 solution and 3 mL of ultrapure water, and stir overnight to form a 3 mL precursor mixed solution. The ion concentration ratio of Ru to Mn is 1:1, and the content of each is 0.7 mmol.

[0034] 2. After cleaning and drying 1×2cm carbon paper, it is immersed in the above-mentioned mixed precursor solution until the surface is completely covered with the precursor. The carbon paper is then removed and vacuum-dried in an oven at 70℃. The dried carbon paper is placed in a muffle furnace and sintered in air at 400℃ with a heating rate of 10℃ / min. After sintering for 3 hours, it is allowed to cool naturally to obtain RuMnO in situ grown on the CFP surface. x catalyst.

[0035] 3. RuMnO x The activation process of the OER catalyst is as follows: a three-electrode system was used, with 0.5 M H2SO4 solution as the electrolyte, a carbon rod as the counter electrode, and a saturated calomel electrode as the reference electrode. The electrochemical activation of the catalyst was performed using a chronoamperometry method, with RuMnO4 catalysts activated separately. x The catalyst was activated at 1.4, 1.1, 0.8 and 1.5 V vs. RHE.

[0036] like Figure 1-4 As shown, the RuMnO2 in situ grown on the CFP surface obtained in Example 1 x In constant voltage tests at 1.4, 1.1, 0.8, and 0.5 V vs. RHE, it was found that the catalyst was activated at a voltage ≤ 1.1 V vs. RHE, and maintained a constant current (10 mA / cm²) in 0.5 M H₂SO₄ electrolyte. 2 It operated stably for 1500 hours in tests. This activation process is due to the Mn in the catalyst undergoing Mn oxidation at lower potential ranges (≤1.1V vs. RHE). IV / Mn II The conversion of Mn IIAs the Mn in the soluble ionic state dissolves on the catalyst surface, leading to the collapse of the surface structure. Combined with ICP characterization results, it was found that the dissolution of both Mn and Ru was intensified. Since Ru is in a deposition range within this potential range, it redeposited on the surface after dissolution. Subsequent characterization revealed that the deposited surface exhibited a higher adsorption degree of hydroxyl oxides (OH), thus facilitating OER and significantly improving catalyst activity. Furthermore, although the catalyst dissolution was severe during activation, it demonstrated ultra-high stability for up to 1500 hours in durability testing.

[0037] The above description of the embodiments is provided to enable those skilled in the art to understand and use the invention. It will be apparent to those skilled in the art that various modifications can be made to these embodiments, and the general principles described herein can be applied to other embodiments without inventive effort. Therefore, the present invention is not limited to the above embodiments, and any improvements and modifications made by those skilled in the art based on the disclosure of the present invention without departing from the scope of the invention should be within the protection scope of the present invention.

Claims

1. A method for preparing a carbon-supported ruthenium manganese oxide anodic oxygen evolution reaction catalyst, characterized in that, Includes the following steps: Step 1: Preparation of RuMnO x The precursor solution contains Ru and Mn ion concentrations in a 1:1 ratio. Step 2: Carbon paper pre-cleaning, RuMnO x The precursor solution was dipped onto the surface of carbon paper, vacuum dried, and then oxidized and sintered in a muffle furnace to obtain carbon-supported ruthenium manganese oxide. The sintering temperature was 400℃, the heating rate of the muffle furnace was 10℃ / min, and after sintering for 3 hours, it was allowed to cool naturally to obtain RuMnO in situ grown on the surface of carbon paper. x catalyst; Step 3: The RuMnO grown in situ on the surface of carbon paper x The catalyst is electrochemically activated to obtain the OER catalyst; The electrochemical activation process includes: using a three-electrode system, employing a chronoamperometry method to activate the RuMnO4 in situ grown on the surface of carbon paper. x The catalyst was activated under an activation voltage of no more than 1.1 V vs. RHE, and the electrolyte was either 0.5 M H2SO4 solution or 0.1 M HClO4 solution.

2. The method for preparing the carbon-supported ruthenium manganese oxide anode oxygen evolution reaction catalyst according to claim 1, characterized in that, In step 1, the vacuum drying temperature is 40-70℃ and the time is 10-20 minutes.

3. The method for preparing the carbon-supported ruthenium manganese oxide anode oxygen evolution reaction catalyst according to claim 1, characterized in that, In step 1, the RuMnO x The preparation method of the precursor solution includes: mixing 138.5 mg MnCl2 precursor with 0.16 g PVP, 145.2 mg RuCl3 solution and 3 mL ultrapure water, stirring overnight to form 3 mL RuMnO x The precursor mixture solution contains Ru and Mn in a 1:1 ratio, each at a concentration of 0.7 mmol.

4. The method for preparing the carbon-supported ruthenium manganese oxide anode oxygen evolution reaction catalyst according to claim 1, characterized in that, In step 2, after the 1×2cm carbon paper is cleaned and dried, it is placed in the RuMnO x Immerse in the precursor solution until the surface is fully covered with RuMnO x After the precursor solution is prepared, the carbon paper is removed and vacuum dried in an oven at 70°C. The dried carbon paper is then placed in a muffle furnace for oxidation sintering in air to obtain RuMnO in situ grown on the surface of the carbon paper. x catalyst.

5. The method for preparing the carbon-supported ruthenium manganese oxide anode oxygen evolution reaction catalyst according to claim 1, characterized in that, In step 3, the RuMnO x The electrochemical activation process of the catalyst includes: using a three-electrode system, with a carbon rod as the counter electrode and a saturated calomel electrode as the reference electrode, and employing a chronoamperometry method to activate the RuMnO4 catalyst grown in situ on the surface of carbon paper. x The catalyst was activated for 1-3 hours at an activation voltage not greater than 1.1V vs. RHE.

6. A carbon-supported ruthenium manganese oxide anode oxygen evolution reaction catalyst, characterized in that, The catalyst was prepared by the method described in any one of claims 1 to 5 for the carbon-supported ruthenium manganese oxide anodic oxygen evolution reaction.

7. The application of the carbon-supported ruthenium manganese oxide anodic oxygen evolution reaction catalyst according to any one of claims 1 to 5 in the oxygen evolution reaction of acidic water electrolysis.

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