TiO2 supported irru-based acidic electrolytic water oxygen evolution electrocatalyst, and preparation method and application thereof
The TiO2-supported IrRuOx catalyst prepared by modifying the TiO2 support and using an in-situ co-reduction process solves the Ru dissolution problem of IrRu catalyst under acidic conditions, achieving high activity and long-term stability, and is suitable for proton exchange membrane water electrolysis hydrogen production applications.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- CHINA UNIV OF PETROLEUM (EAST CHINA)
- Filing Date
- 2026-06-11
- Publication Date
- 2026-07-21
Smart Images
Figure CN122428307A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of proton exchange membrane water electrolysis anode catalyst technology, specifically to a TiO2-supported IrRu composite oxide acidic oxygen evolution catalyst, its preparation method, and its application in a proton exchange membrane water electrolyzer. Background Technology
[0002] Proton exchange membrane (PEM) water electrolysis for hydrogen production has become one of the core technologies for large-scale green hydrogen production due to its advantages such as fast response, high current density, high gas purity, and ease of coupling with renewable energy. The anode of a PEM water electrolyzer needs to operate in a harsh environment of strong acidity and high oxidation potential, which places extremely high demands on the catalytic activity, conductivity, and especially the long-term stability of the oxygen evolution reaction (OER) electrocatalyst.
[0003] Currently, commercially available anolyte OER catalysts are mainly iridium (Ir)-based and ruthenium (Ru)-based oxides: RuO2 exhibits excellent intrinsic OER activity in acidic media, but it is easily oxidized to soluble high-valence ruthenium oxides (such as RuO4) under strong oxidation potentials, resulting in the loss of active components and insufficient stability; IrO2 has much better chemical stability than RuO2 under acidic conditions, but its intrinsic OER activity is low and its cost is high. To balance activity and stability, IrRu bimetallic oxide solid solutions are widely recognized as the most promising solution: by forming atomically mixed IrRuO... x Solid solutions allow for atomic-scale control of electronic structure and optimization of oxygen intermediate adsorption energy, while leveraging the stabilizing effect of Ir to delay Ru dissolution, resulting in superior overall performance compared to single-metal oxides. However, existing IrRu solid solutions still suffer from core drawbacks: firstly, the Ru dissolution problem remains unresolved, leading to continuous Ru loss and rapid performance degradation during long-term operation; secondly, traditional methods struggle to achieve atomically uniform doping of Ir and Ru, resulting in phase separation and weakening of the synergistic effect.
[0004] Therefore, developing a highly stable IrRu solid solution catalyst with uniform composition and stable structure and its controllable preparation method is a key issue that needs to be addressed to promote the commercialization of proton exchange membrane water electrolysis technology. Summary of the Invention
[0005] To address the problems existing in the prior art, and with the aim of reducing the amount of precious metal Ir while improving the acidic OER activity and long-term stability of the catalyst, this invention provides a TiO2-supported IrRu-based acidic water electrolysis oxygen evolution electrocatalyst, its preparation method, and its application.
[0006] A method for preparing an acidic water electrolysis oxygen evolution electrocatalyst includes the following steps:
[0007] S1. Preparation of modified TiO2 support: Triblock copolymer F127, acetic acid, and concentrated hydrochloric acid were dissolved in tetrahydrofuran, stirred evenly, and then tetrabutyl titanate was added. The solvent was evaporated, dried, and the template was removed by low-temperature calcination to obtain primary TiO2 product. The primary TiO2 was ball-milled with salt template, and then placed in an argon atmosphere for high-temperature calcination. After washing to remove the salt template, it was dried to obtain modified TiO2 support.
[0008] S2. Preparation of IrRuO x / TiO2: Ir salt and Ru salt are co-dissolved in deoxygenated deionized water to obtain a metal salt solution; the modified TiO2 support is dispersed in deoxygenated deionized water to obtain a TiO2 dispersion; the metal salt solution is added dropwise to the TiO2 dispersion under ultrasonic conditions, and after uniform adsorption, a reducing agent is added for in-situ co-reduction. After filtration, washing, drying, and low-temperature calcination, the acidic water electrolysis oxygen evolution electrocatalyst is obtained.
[0009] Furthermore, in step S1, the salt template is at least one of sodium chloride and potassium chloride; the mixing mass ratio of the primary TiO2 to the salt template is 1:(5~10).
[0010] Furthermore, in step S1, the high-temperature calcination temperature is 800~900℃, and the holding time is 2~6 h.
[0011] Furthermore, in step S2, the Ir salt is at least one of chloroiridium acid, iridium chloride, and iridium acetylacetonate; the Ru salt is at least one of ruthenium trichloride, ruthenium acetylacetonate, and ruthenium nitrate.
[0012] Furthermore, in step S2, the mass ratio of Ir salt to Ru salt is 1:(1~4).
[0013] Furthermore, in step S2, the reducing agent is at least one of sodium borohydride, ascorbic acid, and hydrazine hydrate.
[0014] Furthermore, in step S2, the temperature of the low-temperature calcination is 300~500℃, and the holding time is 1~3 h.
[0015] Furthermore, in step S2, the deoxygenation process uses either argon or nitrogen.
[0016] Beneficial Effects: Compared with existing technologies, this invention has the following advantages and technical effects: This invention modifies the TiO2 support through salt-template-assisted ball milling and high-temperature argon treatment. This high-temperature treatment improves the crystallinity and conductivity of TiO2, while the salt template's site-occupancy effect suppresses high-temperature sintering, preserving a suitable specific surface area and providing a uniformly dispersed and stable support for the IrRu active component. Through in-situ co-reduction and low-temperature calcination, atomically uniform mixing of IrRu is achieved, while retaining the unique local metal coordination structure. This allows for atomic-scale control of the Ru electronic structure, breaking the inherent contradiction in traditional IrRu systems where "increased activity inevitably leads to decreased stability," achieving both high activity and long-term stability with low Ir dosage. The IrRuO prepared by this invention… x The TiO2 catalyst achieved 10 mA cm⁻¹ in 0.5 M H₂SO₄ solution. -2 A current density requiring only a 204 mV overpotential is achieved in a proton exchange membrane water electrolyzer. -2 The required cell voltage for the current density is only 1.84 V, and 1 Acm -2 It has been running stably for over 540 hours, fully meeting the practical application requirements for hydrogen production via proton exchange membrane water electrolysis, and is suitable for large-scale promotion and application. Attached Figure Description
[0017] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0018] Figure 1 For IrRuO x X-ray diffraction (XRD) pattern of TiO2 catalyst;
[0019] Figure 2 For IrRuO x Transmission electron microscopy (TEM) and elemental distribution map of TiO2 catalyst;
[0020] Figure 3 For IrRuO x High-angle annular dark-field scanning transmission electron microscope image of the TiO2 catalyst;
[0021] Figure 4 For IrRuO x High-angle annular dark-field scanning transmission electron microscope image of / TiO2 catalyst and linear atomic intensity distribution map of the marked area;
[0022] Figure 5For IrRuO x / TiO2、IrRuO x Linear cyclic voltammetry curves were used to test the oxygen evolution performance of TiO2, c-RuO2, and c-IrO2 catalysts.
[0023] Figure 6 For IrRuO x Polarization curves of proton exchange membrane water electrolysis for hydrogen production, tested at different temperatures, with TiO2 catalyst as the anode and commercial Pt / C as the cathode.
[0024] Figure 7 For IrRuO x Using TiO2 catalyst as the anode and commercial Pt / C as the cathode, at 1 A cm⁻¹ -2 Stability test curves at current density. Detailed Implementation
[0025] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as a limitation of the present invention, but rather as a more detailed description of certain aspects, features, and embodiments of the present invention.
[0026] It should be understood that the terminology used in this invention is merely for describing particular embodiments and is not intended to limit the invention. Furthermore, with respect to numerical ranges in this invention, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. Every smaller range between any stated value or intermediate value within a stated range, and any other stated value or intermediate value within said range, is also included in this invention. The upper and lower limits of these smaller ranges may be independently included or excluded from the range.
[0027] Unless otherwise stated, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. While only preferred methods and materials have been described herein, any methods and materials similar or equivalent to those described herein may be used in the implementation or testing of this invention. All references to this specification are incorporated by way of citation to disclose and describe methods and / or materials associated with those references. In the event of any conflict with any incorporated reference, the content of this specification shall prevail.
[0028] Various modifications and variations can be made to the specific embodiments described in this specification without departing from the scope or spirit of the invention, as will be apparent to those skilled in the art. Other embodiments derived from this specification will also be obvious to those skilled in the art. This specification and embodiments are merely exemplary.
[0029] The triblock copolymer in this embodiment of the invention is a polyethylene glycol-polypropylene glycol-polyethylene glycol block copolymer (PEG-PPO-PEG).
[0030] Example 1
[0031] IrRuO in this embodiment 1 x Preparation of TiO2 acidic water electrolysis oxygen evolution catalyst
[0032] (1) Preparation of TiO2 support: 1.6 g F127, 2.4 mL acetic acid, and 1.5 mL concentrated hydrochloric acid were dissolved in 30 mL tetrahydrofuran and stirred for 1 h to obtain a transparent solution; 3.4 mL tetrabutyl titanate was quickly added and stirred to form a golden yellow solution, which was then transferred to two 30×50 mm containers and placed in an oven at 45 °C to evaporate the solvent for 24 h to obtain a white-yellow hydrogel; the hydrogel was then dried in an oven at 80 °C for 15 h and transferred to a muffle furnace at 1 °C min. -1 The temperature was increased to 400℃ at a rising rate and held for 3 h to obtain primary TiO2 product. 50 mg of the primary TiO2 product and 300 mg of NaCl were dissolved in 1 mL of deionized water and ball-milled at 400 rpm for 10 min using a micro-vibrating ball mill. After ball milling, the mixture was transferred to an oven to dry, ground, and then placed in a tube furnace and heated at 5℃ for 1 min under an argon atmosphere. -1 The temperature was increased to 800℃ at a heating rate and held for 2 h. After natural cooling, residual NaCl was removed by repeated washing with deionized water and dried to obtain the modified TiO2 support for later use.
[0033] (2) IrRuO x Preparation of TiO2: Dissolve 8 mg IrCl3 and 32 mg RuCl3 in 20 mL of deionized water deoxygenated by argon, and sonicate until completely dissolved. This solution is recorded as solution 1. Weigh 10 mg of the TiO2 nanoparticles prepared above, dissolve them in 20 mL of deionized water deoxygenated by argon, and sonicate for 10 minutes until completely dispersed. This solution is recorded as solution 2.
[0034] (3) Under ultrasonic conditions, solution 1 was slowly added dropwise to solution 2, and ultrasonication was continued for 10 min after the addition was completed; then 10 mL of 0.5 M NaBH4 solution was added under rapid stirring, and ultrasonic stirring was continued for 30 min; the mixture was filtered, washed, and dried in a vacuum oven at 40℃; the dried product was transferred to a muffle furnace and heated at 5℃ for 1 min. -1 The temperature was increased to 400°C at a heating rate and held for 1 hour to obtain the acidic water electrolysis oxygen evolution electrocatalyst of this embodiment, denoted as IrRuO. x / TiO2.
[0035] IrRuO prepared in Example 1 x The X-ray diffraction pattern of the TiO2 catalyst is shown below. Figure 1 As shown, IrRuO x Except for the composition of anatase TiO2 and rutile TiO2, the characteristic diffraction peak positions of / TiO2 are consistent with those of standard rutile RuO2 and IrO2, proving the successful formation of IrRuO2. x Solid solution.
[0036] IrRuO prepared in Example 1 x Transmission electron microscopy image of the TiO2 catalyst is shown below. Figure 2 As shown, IrRuO x The TiO2 catalyst exhibits a particulate morphology, with Ir and Ru elements uniformly distributed throughout the particles.
[0037] IrRuO prepared in Example 1 x High-angle annular dark-field scanning transmission electron microscopy image of TiO2 catalyst as shown below Figure 3 As shown, the (110) crystal plane of rutile TiO2 and the (110) and (101) crystal planes of RuO2 can be clearly observed.
[0038] IrRuO prepared in Example 1 x High-angle annular dark-field scanning transmission electron microscope image of the TiO2 catalyst and linear atomic intensity distribution map of the marked area are shown below. Figure 4 As shown, differences in electron intensity at metal sites within the RuO2 lattice can be observed. Combined with the linear atomic intensity distribution results, this confirms that Ir atoms successfully replaced Ru atoms in the RuO2 lattice, achieving atomic-level homogeneous mixing, thus proving that IrRuO x The solid solution was successfully prepared.
[0039] Comparative Example 1
[0040] Following the preparation process of Example 1, the difference lies in the absence of iridium trichloride in step (2), and the amount of ruthenium trichloride added is 40 mg, resulting in a single-metal Ru-based acidic water electrolysis oxygen evolution electrocatalyst, denoted as RuO. x / TiO2.
[0041] Comparative Example 2
[0042] The preparation process is the same as in Example 1, except that after the primary TiO2 is prepared in step (1), it is not subjected to NaCl-assisted ball milling and 800℃ argon high-temperature treatment, but is directly used as a carrier to obtain unmodified TiO2-loaded IrRuO2. x Catalyst, denoted as IrRuO x / O-TiO2.
[0043] Application Example 1
[0044] The catalytic performance of the acid oxygen evolution reaction of Example 1, Comparative Example 1, commercial RuO2 and commercial IrO2 catalysts was tested in a three-electrode system using linear voltammetry. The specific test method was as follows: the catalyst was prepared into ink and dropped onto a glassy carbon electrode as the working electrode, with reversible hydrogen as the reference electrode and a carbon rod as the counter electrode. The electrocatalytic oxygen evolution performance was tested in 0.5 M H2SO4 solution.
[0045] IrRuO prepared in Example 1 x The linear cyclic voltammetric curves for testing the oxygen evolution performance of the TiO2 catalyst are shown below. Figure 5 As shown, at 10 mA cm -2 The overpotential at the current density is 204 mV.
[0046] Application Example 2
[0047] Prepared IrRuO x / TiO2 catalyst is used in proton exchange membrane water electrolysis to produce hydrogen. The specific test method is as follows: IrRuO x Using TiO2 catalyst as the anode, commercial Pt / C as the cathode, and Nafion 212 membrane as the proton exchange membrane, the polarization curves of proton exchange membrane electrolysis for hydrogen production were tested at different temperatures.
[0048] IrRuO prepared in Example 1 x The polarization curves of proton exchange membrane water electrolysis for hydrogen production using TiO2 catalyst are shown below. Figure 6 As shown, it reaches 3 A cm at 70℃. -2 The current density requires a cell voltage of only 1.84 V.
[0049] IrRuO prepared in Example 1 x The stability curve of proton exchange membrane water electrolysis for hydrogen production using TiO2 catalyst is shown in the figure. Figure 7 As shown, at 60°C, at 1 A cm -2 The current density operated stably for 540 hours.
[0050] The above are merely preferred embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention.
Claims
1. A method for preparing an acidic water electrolysis oxygen evolution electrocatalyst, characterized in that, Includes the following steps: S1. Preparation of modified TiO2 support: Triblock copolymer F127, acetic acid, and concentrated hydrochloric acid were dissolved in tetrahydrofuran, stirred evenly, and then tetrabutyl titanate was added. After evaporating the solvent, drying, and calcining at low temperature to remove the template, a primary TiO2 product was obtained. The primary TiO2 was ball-milled with a salt template, and then calcined at high temperature under an argon atmosphere. After washing to remove the salt template, it was dried to obtain a modified TiO2 support. S2. Preparation of IrRuO x / TiO2: Ir salt and Ru salt are co-dissolved in deoxygenated deionized water to obtain a metal salt solution; the modified TiO2 support is dispersed in deoxygenated deionized water to obtain a TiO2 dispersion; the metal salt solution is added dropwise to the TiO2 dispersion under ultrasonic conditions, and after uniform adsorption, a reducing agent is added for in-situ co-reduction. After filtration, washing, drying, and low-temperature calcination, the acidic water electrolysis oxygen evolution electrocatalyst is obtained.
2. The preparation method according to claim 1, characterized in that, In step S1, the salt template is at least one of sodium chloride and potassium chloride; the mass ratio of TiO2 to the salt template is 1:(5~10).
3. The preparation method according to claim 1, characterized in that, In step S1, the high-temperature calcination temperature is 800~900℃, and the holding time is 2~6 h.
4. The preparation method according to claim 1, characterized in that, In step S2, the mass ratio of Ir salt to Ru salt is 1:(1~4).
5. The preparation method according to claim 1, characterized in that, In step S2, the Ir salt is at least one of chloroiridium acid, iridium chloride, and iridium acetylacetonate; the Ru salt is at least one of ruthenium trichloride, ruthenium acetylacetonate, and ruthenium nitrate.
6. The preparation method according to claim 1, characterized in that, In step S2, the reducing agent is at least one of sodium borohydride, ascorbic acid, and hydrazine hydrate.
7. The preparation method according to claim 1, characterized in that, In step S2, the temperature of the low-temperature calcination is 300~500℃, and the holding time is 1~3 h.
8. The preparation method according to claim 1, characterized in that, In step S2, the deoxygenation process uses either argon or nitrogen.
9. An acidic water electrolysis oxygen evolution electrocatalyst prepared by the preparation method according to any one of claims 1 to 8.
10. The application of the acidic water electrolysis oxygen evolution electrocatalyst according to claim 9 in proton exchange membrane water electrolysis for hydrogen production.