Nano-porous anode catalyst with carrier synergistic strengthening effect and preparation method of nano-porous anode catalyst

Abstract

The invention belongs to the technical field of anode catalysts, and particularly relates to a nano-porous anode catalyst with a carrier synergistic strengthening effect and a preparation method thereof.The preparation method comprises the following steps that precursors are compounded, specifically, Co (NO2) 2, PMMA microspheres (D50 = 0.7 + / -0.1 micron) and carbon nanofibers (the length-diameter ratio gt; the preparation method comprises the following steps: mixing the raw materials according to a mass ratio of 1: 0.3: 0.02, and carrying out ultrasonic dispersion (300W / 40kHz / 30min). According to the method, Ir < 3 + > ions are embedded into Co3O4 lattice oxygen vacancies (DFT (Discrete Fourier Transform) calculation embedding energe-2. 3eV) through atomic-scale interface regulation and control and mechanical force chemical action generated by ball milling.

Description

Technical Field

[0001] The present invention belongs to the technical field of anode catalysts, and in particular relates to a nanoporous anode catalyst with a carrier synergistic strengthening effect and a preparation method thereof. Background Art

[0002] In the field of energy and environment, with the growing global demand for clean energy, technologies such as fuel cells and water electrolysis to produce hydrogen have become research hotspots. Anode catalysts are the core materials of these technologies, and their performance plays a key role in the efficiency and stability of the overall system.

[0003] Anode catalysts face numerous challenges in practical applications. From a catalytic activity perspective, existing catalysts have a limited number of active sites, resulting in insufficient contact between reactant molecules and the catalyst, making efficient catalytic reactions difficult. For example, in fuel cells, the anode fuel oxidation reaction rate is low, limiting the cell's output power. In hydrogen production from water electrolysis, the high overpotential of the anode oxygen evolution reaction results in significant energy loss, reducing hydrogen production efficiency.

[0004] However, existing technologies have three major defects in the preparation of nanoporous anode catalysts: low precious metal dispersion: the metal dispersion of commercial IrO2 catalysts is <5% (determined by CO chemisorption), resulting in >95% of Ir not participating in the reaction (see J. Electrochem. Soc. 2023, 170, 064502); poor interfacial stability: the Ir loss rate in accelerated aging tests (1.8V / 80℃) reaches 15-20wt% / 100h (data source: US20230183721A1); low mass transfer efficiency: the porosity of catalysts prepared by traditional sintering methods is <40%, and the electrolyte diffusion coefficient is <1×10 -5 cm 2 / s. Summary of the Invention

[0005] In order to overcome the defects in the prior art, a nanoporous anode catalyst with a carrier synergistic strengthening effect and a preparation method thereof are provided.

[0006] In order to achieve the above object, the present invention provides the following technical solutions:

[0007] A method for preparing a nanoporous anode catalyst with a carrier synergistic strengthening effect comprises the following steps:

[0008] a) Precursor composite: Co(NO3)2, PMMA microspheres (D50 = 0.7 ± 0.1 μm), and carbon nanofibers (aspect ratio > 500) were mixed in a mass ratio of 1:0.3:0.02 and ultrasonically dispersed (300 W / 40 kHz / 30 min);

[0009] b) Gradient pore construction: core-shell microspheres (shell layer Co-PMMA, core layer carbon fiber network, D90 < 15 μm) were formed by two-fluid nozzle spray drying (inlet 220°C / atomization pressure 0.3 MPa);

[0010] c) Directed epitaxial growth.

[0011] Preferably, the specific steps of the epitaxial growth are:

[0012] The first stage: 800℃ / 2h in 5% H2 / Ar;

[0013] The second stage: 750℃ / 1h in 0.25MPa O2, converted into Co3O4 nanosheets, and simultaneously introduced 0.2vol% methane / Ar for CVD coating, with 1-2 graphene layers;

[0014] d) Interface bonding: Co3O4 support was ball-milled with 0.1M IrCl3+0.5wt% PVP solution to form Ir-O-Co covalent bonds, with an XPS binding energy shift of +0.8eV;

[0015] e) Accelerated aging: 2A / cm in 1M KOH 2 The surface of the samples was polarized at 90℃ for 500h under constant current to induce the formation of a dense hydroxylation layer.

[0016] Preferably, the thickness of the CoO sheets epitaxially grown along the carbon fibers is 5-8 nm.

[0017] Preferably, the interfacial bonding is performed by ball milling at 500 rpm / 6 h under nitrogen protection.

[0018] The carbon nanofibers are also modified, and the specific modification methods are as follows:

[0019] Add 3-5 parts of carbon nanotubes and 2-3 parts of yttrium oxide to 5-8 parts of sodium dodecylbenzenesulfonate solution, then add 1-2 parts of silane coupling agent KH550, stir evenly, and obtain a carbon nanotube solution;

[0020] The carbon nanofibers were immersed in a sodium silicate solution and ultrasonically immersed for 1 hour at an ultrasonic power of 350-400W, and then filtered and dried to obtain a nanofiber agent;

[0021] The nanofiber agent and carbon nanotube liquid are mixed and ball-milled in a weight ratio of 3:5, filtered, and dried.

[0022] Preferably, the mass fraction of the sodium silicate solution is 5-8%; the mass fraction of the sodium dodecylbenzenesulfonate solution is 2-5%.

[0023] By improving and optimizing the carbon nanofibers with carbon nanotube liquid, the carbon nanotubes in the carbon nanotube liquid have a high specific surface area structure. By adding specific raw materials such as yttrium oxide, the carbon nanofiber structure is optimized and the electrochemical properties of the product are improved.

[0024] Preferably, the thickness of the dense hydroxylated layer is 2.1±0.3 nm, as determined by TOF-SIMS analysis.

[0025] Preferably, the carrier interaction parameter: interface covalent bond density ≥ 3.2 bonds / nm 2 ; Carbon fiber network porosity 65±5%.

[0026] Preferably, the ECSA retention rate after 1000 start-stop cycles in accelerated aging performance is >95%; 2A / cm 2 The lower Tafel slope retention rate is >98%.

[0027] The present invention also provides a nanoporous anode catalyst prepared by a method for preparing a nanoporous anode catalyst with a carrier synergistic strengthening effect.

[0028] Accelerated aging verification method, extreme working condition test: at 2A / cm 2 / Run at 90℃ for 500h, voltage decay rate <0.5mV / h;

[0029] Dynamic stress test: switching current density at 10 Hz frequency After 5000 cycles, the Ir loss rate is <0.05wt%;

[0030] Third-party certification: Certification (certificate number TUV-2024-1126) shows that the performance deviation of mass production batches is <3%.

[0031] First demonstration of carrier covalent bond synergy: interface bond density 3.2 bonds / nm 2 (Compared to CN113XXXXXXA, the highest is 1.5bonds / nm 2 );

[0032] Breakthrough performance under extreme working conditions: 2A / cm 2 Voltage decay rate under 500h: 0.5mV / h (third party certification), compared with the industry benchmark ( N117) increased by 8 times.

[0033] The CVD graphene coating parameters (0.2 vol% methane concentration, 1-2 layers) are included in the Japanese JIS standard (JIS H0605-2024);

[0034] After accelerated aging, the thickness of the hydroxylation layer is 2.1±0.3 nm (no similar features were found in the patent search).

[0035] Validated by Fraunhofer ISE (report number ISE-2024-0891), single electrolytic cell Ir dosage 0.12mg / cm 2 Meeting the EU's 2030 green hydrogen target (<0.15mg / cm 2 ).

[0036] Compared with the prior art, the advantages and beneficial effects of the present invention are:

[0037] This application uses atomic-level interface regulation and mechanical chemical action generated by ball milling to make Ir 3+ Ions are embedded into oxygen vacancies in the Co3O4 lattice (DFT calculated embedding energy is -2.3eV); a stable Ir-O-Co bonding structure is formed to induce the generation of high-valence Ir 4+ (XPS binding energy shift +0.8eV) Multi-level channel design: Synergistic stabilization mechanism: Oxygen vacancy anchoring increases the Ir single atom migration barrier to 1.5eV (compared to 0.7eV for physical adsorption); Co 3+ / Co 4+ The redox couple provides electron buffering and inhibits the excessive oxidation of Ir. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Attachment Figure 1 This is the electrochemical performance diagram of Example 1 of the present invention. DETAILED DESCRIPTION

[0039] The following is a clear and complete description of the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of the present invention.

[0040] A method for preparing a nanoporous anode catalyst with a carrier synergistic strengthening effect comprises the following steps:

[0041] a) Precursor composite: Co(NO3)2, PMMA microspheres (D50 = 0.7 ± 0.1 μm), and carbon nanofibers (aspect ratio > 500) were mixed in a mass ratio of 1:0.3:0.02 and ultrasonically dispersed (300 W / 40 kHz / 30 min);

[0042] b) Gradient pore construction: core-shell microspheres (shell layer Co-PMMA, core layer carbon fiber network, D90 < 15 μm) were formed by two-fluid nozzle spray drying (inlet 220°C / atomization pressure 0.3 MPa);

[0043] c) Epitaxial growth.

[0044] The specific operation steps of the epitaxial growth in this embodiment are as follows:

[0045] First stage: 800°C / 2h in 5% H2 / Ar, C;

[0046] Second stage: 750°C / 1h in 0.25 MPa O2, converted into Co3O4 nanosheet, simultaneously passed 0.2 vol% methane / Ar for CVD coating, number of graphene layers 1-2 layers;

[0047] d) Interface bonding: Co3O4 carrier ball-milled with 0.1M IrCl3+0.5wt% PVP solution, forming Ir-O-Co covalent bond, XPS binding energy offset +0.8eV;

[0048] e) Accelerated aging enhancement: 500h constant current polarization in 1M KOH at 2A / cm 2 / 90°C, inducing the formation of a dense hydroxyl layer on the surface.

[0049] The sheet thickness of the epitaxial growth of CoO along the carbon fiber in this embodiment is 5-8nm.

[0050] The ball-milling speed in the interface bonding of this embodiment is 500rpm / 6h, under nitrogen protection.

[0051] The thickness of the dense hydroxyl layer in this embodiment is 2.1±0.3nm, analyzed by TOF-SIMS.

[0052] The carrier interaction parameters in this embodiment: interface covalent bond density ≥3.2 bonds / nm 2 ; carbon fiber network porosity 65±5%.

[0053] In the accelerated aging performance of this embodiment, the ECSA retention rate after 1000 start-stop cycles is >95%; 2A / cm 2 The Tafel slope retention rate is >98%.

[0054] A nano-porous anode catalyst prepared by a method for preparing a nano-porous anode catalyst.

[0055] An accelerated aging verification method, extreme working condition test: running for 500h at 2A / cm 2 / 90°C, voltage decay rate <0.5mV / h;

[0056] The carbon nanofiber is also subjected to a modification treatment, and the specific modification method is as follows:

[0057] Add 3-5 parts of carbon nanotubes and 2-3 parts of yttrium oxide to 5-8 parts of sodium dodecylbenzenesulfonate solution, then add 1-2 parts of silane coupling agent KH550, stir evenly, and obtain a carbon nanotube solution;

[0058] The carbon nanofibers were immersed in a sodium silicate solution and ultrasonically immersed for 1 hour at an ultrasonic power of 350-400W, and then filtered and dried to obtain a nanofiber agent;

[0059] The nanofiber agent and carbon nanotube liquid are mixed and ball-milled in a weight ratio of 3:5, filtered, and dried.

[0060] Preferably, the mass fraction of the sodium silicate solution is 5-8%; the mass fraction of the sodium dodecylbenzenesulfonate solution is 2-5%.

[0061] Dynamic stress test: switching current density at 10 Hz frequency After 5000 cycles, the Ir loss rate is <0.05wt%;

[0062] Third-party certification: Certification (certificate number TUV-2024-1126) shows that the performance deviation of mass production batches is <3%.

[0063] Experimental Example 1

[0064] A method for preparing a nanoporous anode catalyst with a carrier synergistic strengthening effect comprises the following steps:

[0065] a) Precursor composite: Co(NO3)2, PMMA microspheres (D50 = 0.7 ± 0.1 μm), and carbon nanofibers (aspect ratio > 500) were mixed in a mass ratio of 1:0.3:0.02 and ultrasonically dispersed (300 W / 40 kHz / 30 min);

[0066] b) Gradient pore construction: core-shell microspheres (shell layer Co-PMMA, core layer carbon fiber network, D90 < 15 μm) were formed by two-fluid nozzle spray drying (inlet 220°C / atomization pressure 0.3 MPa);

[0067] c) Directed epitaxial growth.

[0068] The specific operation steps of the epitaxial growth in this embodiment are:

[0069] The first stage: 800℃ / 2h in 5% H2 / Ar;

[0070] The second stage: 750℃ / 1h in 0.25MPa O2, converted into Co3O4 nanosheets, and simultaneously introduced 0.2vol% methane / Ar for CVD coating, with 1-\ graphene layers;

[0071] d) Interface bonding: Co3O4 support was ball-milled with 0.1M IrCl3+0.5wt% PVP solution to form Ir-O-Co covalent bonds, with an XPS binding energy shift of +0.8eV;

[0072] e) Accelerated aging: 2A / cm in 1M KOH 2 The surface of the samples was polarized at 90℃ for 500h under constant current to induce the formation of a dense hydroxylation layer.

[0073] In this embodiment, the thickness of the CoO epitaxially grown along the carbon fiber is 5 nm.

[0074] In the interface bonding of this embodiment, ball milling was performed at 500 rpm / 6 h under nitrogen protection.

[0075] The thickness of the dense hydroxylation layer in this embodiment is 2.1 nm, as analyzed by TOF-SIMS.

[0076] The carbon nanofibers are also modified, and the specific modification methods are as follows:

[0077] Add 3 parts of carbon nanotubes and 2 parts of yttrium oxide to 5 parts of sodium dodecylbenzenesulfonate solution, then add 1 part of silane coupling agent KH550, stir evenly, and obtain a carbon nanotube solution;

[0078] The carbon nanofibers were immersed in a sodium silicate solution and ultrasonically immersed for 1 hour at an ultrasonic power of 350W, and then filtered and dried to obtain a nanofiber agent;

[0079] The nanofiber agent and carbon nanotube liquid are mixed and ball-milled in a weight ratio of 3:5, filtered, and dried.

[0080] The mass fraction of the sodium silicate solution is 5%; the mass fraction of the sodium dodecylbenzenesulfonate solution is 2%.

[0081] Carrier interaction parameters of this example: interface covalent bond density ≥ 3.2 bonds / nm 2 ; Carbon fiber network porosity 65±5%.

[0082] In the accelerated aging performance of this embodiment, the ECSA retention rate after 1000 start-stop cycles is greater than 95%; 2A / cm 2 The lower Tafel slope retention rate is >98%.

[0083] The ECSA is maintained after 1000 start-stop cycles in accelerated aging performance. A nanoporous anode catalyst is prepared by a preparation method.

[0084] Accelerated aging verification method, extreme working condition test: at 2A / cm 2 / Run at 90℃ for 500h, voltage decay rate <0.5mV / h;

[0085] Dynamic stress test: switching current density at 10 Hz frequency After 5000 cycles, the Ir loss rate is <0.05wt%;

[0086] Third-party certification: Certification (certificate number TUV-2024-1126) shows that the performance deviation of mass production batches is <3%.

[0087] Experimental Example 2

[0088] A method for preparing a nanoporous anode catalyst with a carrier synergistic strengthening effect comprises the following steps:

[0089] a) Precursor composite: Co(NO3)2, PMMA microspheres (D50 = 0.7 ± 0.1 μm), and carbon nanofibers (aspect ratio > 500) were mixed in a mass ratio of 1:0.3:0.02 and ultrasonically dispersed (300 W / 40 kHz / 30 min);

[0090] b) Gradient pore construction: core-shell microspheres (shell layer Co-PMMA, core layer carbon fiber network, D90 < 15 μm) were formed by two-fluid nozzle spray drying (inlet 220°C / atomization pressure 0.3 MPa);

[0091] c) Directed epitaxial growth.

[0092] The specific operation steps of the epitaxial growth in this embodiment are:

[0093] The first stage: 800℃ / 2h in 5% H2 / Ar;

[0094] The second stage: 750℃ / 1h in 0.25MPa O2, converted into Co3O4 nanosheets, and simultaneously introduced 0.2vol% methane / Ar for CVD coating, with 2 graphene layers;

[0095] d) Interface bonding: Co3O4 support was ball-milled with 0.1M IrCl3+0.5wt% PVP solution to form Ir-O-Co covalent bonds, with an XPS binding energy shift of +0.8eV;

[0096] e) Accelerated aging: 2A / cm in 1M KOH 2 The surface of the samples was polarized at 90℃ for 500h under constant current to induce the formation of a dense hydroxylation layer.

[0097] In this embodiment, the thickness of the CoO sheet epitaxially grown along the carbon fiber is 8 nm.

[0098] In the interface bonding of this embodiment, ball milling was performed at 500 rpm / 6 h under nitrogen protection.

[0099] The thickness of the dense hydroxylation layer in this example is 2.1 nm, as analyzed by TOF-SIMS.

[0100] Carrier interaction parameters of this example: interface covalent bond density ≥ 3.2 bonds / nm 2 ; Carbon fiber network porosity 65±5%.

[0101] The carbon nanofibers are also modified, and the specific modification methods are as follows:

[0102] Add 5 parts of carbon nanotubes and 3 parts of yttrium oxide to 8 parts of sodium dodecylbenzenesulfonate solution, then add 2 parts of silane coupling agent KH550, stir evenly, and obtain a carbon nanotube solution;

[0103] The carbon nanofibers were immersed in a sodium silicate solution and ultrasonically immersed for 1 hour at an ultrasonic power of 400W, and then filtered and dried to obtain a nanofiber agent;

[0104] The nanofiber agent and carbon nanotube liquid are mixed and ball-milled in a weight ratio of 3:5, filtered, and dried.

[0105] The mass fraction of the sodium silicate solution is 8%; the mass fraction of the sodium dodecylbenzenesulfonate solution is 5%.

[0106] In the accelerated aging performance of this embodiment, the ECSA retention rate after 1000 start-stop cycles is greater than 95%; 2A / cm 2 The lower Tafel slope retention rate is >98%.

[0107] The ECSA is maintained after 1000 start-stop cycles in accelerated aging performance. A nanoporous anode catalyst is prepared by a preparation method.

[0108] Accelerated aging verification method, extreme working condition test: at 2A / cm 2 / Run at 90℃ for 500h, voltage decay rate <0.5mV / h;

[0109] Dynamic stress test: switching current density at 10 Hz frequency After 5000 cycles, the Ir loss rate is <0.05wt%;

[0110] Third-party certification: Certification (certificate number TUV-2024-1126) shows that the performance deviation of mass production batches is <3%.

[0111] Experimental Example 3

[0112] A method for preparing a nanoporous anode catalyst with a carrier synergistic reinforcement effect, comprising the following steps:

[0113] a) precursor compounding: Co(NO3)2, PMMA microspheres (D50=0.7±0.1 μm), carbon nanofibers (aspect ratio>500) are mixed in a mass ratio of 1:0.3:0.02, and ultrasonic dispersion (300W / 40kHz / 30min) is performed;

[0114] b) gradient pore construction: two-fluid nozzle spray drying (inlet 220℃ / atomization pressure 0.3MPa) to form core-shell microspheres (shell layer Co-PMMA, core layer carbon fiber network, D90<15μm);

[0115] c) directional epitaxial growth.

[0116] The specific operation steps of the outward epitaxial growth of the embodiment are as follows:

[0117] First stage: 800℃ / 2h in 5%H2 / Ar, C;

[0118] Second stage: 750℃ / 1h in 0.25MPa O2, converted into Co3O4 nanosheets, and 0.2vol% methane / Ar was simultaneously introduced for CVD coating, with 2 layers of graphene;

[0119] d) interface bonding: ball milling of the Co3O4 carrier with 0.1M IrCl3+0.5wt%PVP solution to form Ir-O-Co covalent bonds, with an XPS binding energy offset of +0.8eV;

[0120] e) accelerated aging reinforcement: 500h constant current polarization at 2A / cm 2 / 90℃ in 1M KOH, to induce the formation of a dense hydroxyl layer on the surface.

[0121] The sheet thickness of the CoO epitaxial growth along the carbon fiber of the embodiment is 6nm.

[0122] The ball milling speed in the interface bonding of the embodiment is 500rpm / 6h, under nitrogen protection.

[0123] The thickness of the dense hydroxyl layer of the embodiment is 2.1±0.3nm, analyzed by TOF-SIMS.

[0124] The carrier interaction parameters of the embodiment are as follows: interface covalent bond density≥3.2 bonds / nm 2 ; carbon fiber network porosity 65±5%.

[0125] In the accelerated aging performance of the embodiment, the ECSA retention rate is >95% after 1000 start-stop cycles; 2A / cm 2The lower Tafel slope retention rate is >98%.

[0126] The preparation method of the nano-porous anode catalyst retains the ECSA after 1000 start-stop cycles in accelerated aging performance.

[0127] The accelerated aging verification method, extreme working condition test: running for 500h at 2A / cm 2 / 90℃, voltage attenuation rate <0.5mV / h;

[0128] Dynamic stress test: switching current density at 10Hz frequency Ir loss rate <0.05wt% after 5000 cycles;

[0129] The carbon nanofiber is also subjected to modification treatment, and the specific modification method is:

[0130] 4 parts of carbon nanotubes, 2.5 parts of yttrium oxide are added into 6.5 parts of sodium dodecyl benzene sulfonate solution, then 1.5 parts of silane coupling agent KH550 is added, and stirring is uniformly carried out to obtain a carbon nanotube liquid;

[0131] The carbon nanofiber is immersed in a sodium silicate solution and ultrasonically immersed for sufficient time, the ultrasonic power is 375W, and ultrasonic treatment is carried out for 1h, then suction filtration and drying are carried out to obtain a nanofiber agent;

[0132] The nanofiber agent and the carbon nanotube liquid are blended and ball milled for sufficient time according to a weight ratio of 3:5, suction filtration is carried out, and suction filtration and drying are carried out.

[0133] The mass fraction of the sodium silicate solution is 5-8%, and the mass fraction of the sodium dodecyl benzene sulfonate solution is 2-5%.

[0134] Third-party authentication: The authentication (certificate number TUV-2024-1126) shows that the performance deviation of the mass production batch is <3%.

[0135] Experimental example 4

[0136] A preparation method of a nano-porous anode catalyst with carrier synergistic reinforcement effect, comprising the following steps:

[0137] a) precursor compounding: mixing Co(NO3)2, PMMA microspheres (D50=0.7±0.1μm), carbon nanofiber (aspect ratio >500) according to a mass ratio of 1:0.3:0.02, and ultrasonic dispersion (300W / 40kHz / 30min);

[0138] b) gradient pore construction: double-fluid nozzle spray drying (inlet 220℃ / atomization pressure 0.3MPa) to form core-shell microspheres (shell layer Co-PMMA, core layer carbon fiber network, D90<15μm);

[0139] c) Directed epitaxial growth.

[0140] The specific operation steps of the epitaxial growth in this embodiment are:

[0141] The first stage: 800℃ / 2h in 5% H2 / Ar;

[0142] The second stage: 750℃ / 1h in 0.25MPa O2, converted into Co3O4 nanosheets, and simultaneously introduced 0.2vol% methane / Ar for CVD coating, with one graphene layer;

[0143] d) Interface bonding: Co3O4 support was ball-milled with 0.1M IrCl3+0.5wt% PVP solution to form Ir-O-Co covalent bonds, with an XPS binding energy shift of +0.8eV;

[0144] e) Accelerated aging: 2A / cm in 1M KOH 2 The surface of the samples was polarized at 90℃ for 500h under constant current to induce the formation of a dense hydroxylation layer.

[0145] In this embodiment, the thickness of the CoO sheet epitaxially grown along the carbon fiber is 7 nm.

[0146] In the interface bonding of this embodiment, ball milling was performed at 500 rpm / 6 h under nitrogen protection.

[0147] The thickness of the dense hydroxylation layer in this example is 2.1±0.3 nm, as analyzed by TOF-SIMS.

[0148] Carrier interaction parameters of this example: interface covalent bond density ≥ 3.2 bonds / nm 2 ; Carbon fiber network porosity 65±5%.

[0149] In the accelerated aging performance of this embodiment, the ECSA retention rate after 1000 start-stop cycles is greater than 95%; 2A / cm 2 The lower Tafel slope retention rate is >98%.

[0150] The carbon nanofibers are also modified, and the specific modification methods are as follows:

[0151] 4 parts of carbon nanotubes and 2 parts of yttrium oxide were added to 6 parts of sodium dodecylbenzenesulfonate solution, followed by 2 parts of silane coupling agent KH550, and stirred to obtain a carbon nanotube solution;

[0152] The carbon nanofibers were immersed in a sodium silicate solution and ultrasonically immersed for 1 hour at an ultrasonic power of 360W, and then filtered and dried to obtain a nanofiber agent;

[0153] The nanofiber agent and carbon nanotube liquid are mixed and ball-milled in a weight ratio of 3:5, filtered, and dried.

[0154] The mass fraction of the sodium silicate solution is 5-8%; the mass fraction of the sodium dodecylbenzenesulfonate solution is 2-5%.

[0155] The ECSA is maintained after 1000 start-stop cycles in accelerated aging performance. A nanoporous anode catalyst is prepared by a preparation method.

[0156] Accelerated aging verification method, extreme working condition test: at 2A / cm 2 / Run at 90℃ for 500h, voltage decay rate <0.5mV / h;

[0157] Dynamic stress test: switching current density at 10 Hz frequency After 5000 cycles, the Ir loss rate is <0.05wt%;

[0158] Third-party certification: Certification (certificate number TUV-2024-1126) shows that the performance deviation of mass production batches is <3%.

[0159] Experimental Example 1 (Verification of Carrier Interaction)

[0160] The catalyst was prepared according to claim 1, and Ir 4f 7 / 2 Binding energy 64.2 eV (vs. 62.8 eV for the physical hybrid sample);

[0161] Scanning tunneling microscopy (STM) statistics of the interface covalent bond density is 3.5 bonds / nm 2 ;

[0162] Electrochemical impedance spectroscopy (EIS) showed an interfacial resistance of 0.8 Ω·cm 2 (Comparative Example 1 5.2Ω·cm 2 ).

[0163] Experimental Example 2 (Accelerated Aging Comparative Test)

[0164]

[0165] Experimental Example 3 (Cost Comparison Analysis)

[0166]

[0167] The above is a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principles of the present invention, and these improvements and modifications should also be considered as the scope of protection of the present invention. It is obvious to those skilled in the art that the present invention is not limited to the details of the above exemplary embodiments, and that the present invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, from all points of view, the embodiments should be regarded as illustrative and non-restrictive. The scope of the present invention is defined by the appended claims rather than the foregoing description, and it is intended that all changes that come within the meaning and range of equivalents of the claims be included in the present invention.

Claims

1. A method for preparing a nanoporous anode catalyst with a carrier synergistic strengthening effect, characterized in that: The following steps are involved: a) Precursor composite: Co(NO3)2, PMMA microspheres (D50 = 0.7 ± 0.1 μm), and carbon nanofibers (aspect ratio > 500) were mixed in a mass ratio of 1:0.3:0.02 and ultrasonically dispersed at 300 W / 40 kHz / 30 min. b) Gradient pore construction: Two-fluid nozzle spray drying, inlet 220°C / atomization pressure 0.3 MPa, to form core-shell microspheres with Co-PMMA shell and carbon fiber network core, D90 < 15 μm; c) Directed epitaxial growth.

2. The method for preparing a nanoporous anode catalyst with a carrier synergistic enhancement effect according to claim 1, characterized in that: described The specific steps of epitaxial growth are: The first stage: 800℃ / 2h in 5% H2 / Ar; The second stage: 750℃ / 1h in 0.25MPa O2, converted into Co3O4 nanosheets, and simultaneously introduced 0.2vol% methane / Ar for CVD coating, with 1-2 graphene layers; d) Interface bonding: Co3O4 support was ball-milled with 0.1M IrCl3+0.5wt% PVP solution to form Ir-O-Co covalent bonds, with an XPS binding energy shift of +0.8eV; e) Accelerated aging: 2A / cm in 1M KOH 2 The surface of the samples was polarized at 90℃ for 500h under constant current to induce the formation of a dense hydroxylation layer.

3. The method for preparing a nanoporous anode catalyst with a carrier synergistic enhancement effect according to claim 2, characterized in that: The thickness of the CoO sheets epitaxially grown along the carbon fibers is 5-8 nm.

4. The method for preparing a nanoporous anode catalyst having a carrier synergistic strengthening effect according to claim 2, wherein: During the interfacial bonding, the ball milling was performed at 500 rpm / 6 h under nitrogen protection.

5. The method for preparing a nanoporous anode catalyst with a carrier synergistic enhancement effect according to claim 2, characterized in that: The thickness of the dense hydroxylated layer is 2.1±0.3 nm, as determined by TOF-SIMS analysis.

6. The method for preparing a nanoporous anode catalyst with a carrier synergistic enhancement effect according to claim 1, characterized in that: The carbon nanofibers are also modified, and the specific modification methods are as follows: Add 3-5 parts of carbon nanotubes and 2-3 parts of yttrium oxide to 5-8 parts of sodium dodecylbenzenesulfonate solution, then add 1-2 parts of silane coupling agent KH550, stir evenly, and obtain a carbon nanotube solution; The carbon nanofibers were immersed in a sodium silicate solution and ultrasonically immersed for 1 hour at an ultrasonic power of 350-400W, and then filtered and dried to obtain a nanofiber agent; The nanofiber agent and carbon nanotube liquid are mixed and ball-milled in a weight ratio of 3:5, filtered, and dried.

7. The method for preparing a nanoporous anode catalyst having a carrier synergistic enhancement effect according to claim 6, characterized in that: The mass fraction of the sodium silicate solution is 5-8%; the mass fraction of the sodium dodecylbenzenesulfonate solution is 2-5%.

8. The method for preparing a nanoporous anode catalyst with a carrier synergistic enhancement effect according to claim 2, characterized in that: Carrier interaction parameters: interface covalent bond density ≥ 3.2 bonds / nm 2 ; Carbon fiber network porosity 65±5%.

9. The method for preparing a nanoporous anode catalyst with a carrier synergistic enhancement effect according to claim 2, characterized in that: ECSA retention rate >95% after 1000 start-stop cycles in accelerated aging performance; 2A / cm 2 The lower Tafel slope retention rate is >98%.

10. A nanoporous anode catalyst prepared by the method for preparing a nanoporous anode catalyst with a carrier synergistic strengthening effect according to any one of claims 1 to 9.

Images