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CN-122010190-A - High-entropy cobalt-based double perovskite solid oxide cathode material with A-site defect regulation and control function, and preparation method and application thereof

CN122010190ACN 122010190 ACN122010190 ACN 122010190ACN-122010190-A

Abstract

The invention belongs to the technical field of solid oxide fuel cell cathode materials, and discloses an A-site defect-regulated high-entropy cobalt-based double perovskite solid oxide cathode material, and a preparation method and application thereof. The cathode material consists of an A-site defect type derivative of basic high-entropy cobalt-based double perovskite, wherein the A-site defect type derivative is (Gd 1/6 Pr 1/6 La 1/6 Ba 1/6 Sr 1/6 Ca 1/6 ) 0.93 CoO 3 . The invention solves the contradiction between the activity, the stability and the process suitability of the existing cathode material through the cooperative strategy of 'high-entropy structural design+A-site defect engineering', and can be widely applied to the electrocatalytic fields such as electrocatalytic oxygen precipitation, carbon dioxide reduction and the like.

Inventors

  • CAO JIAFENG
  • CHEN XUETING
  • A RUHAN

Assignees

  • 内蒙古工业大学

Dates

Publication Date
20260512
Application Date
20260416

Claims (8)

  1. 1. A high-entropy cobalt-based double perovskite solid oxide cathode material with A-site defect regulation is characterized by comprising an A-site defect type derivative of basic high-entropy cobalt-based double perovskite, The A-site defect type derivative is prepared by introducing 7% of A-site cation defects into a basic high-entropy cobalt-based double perovskite structure; the A site of the basic high-entropy cobalt-based double perovskite structure consists of Gd, pr, la, ba, sr and Ca according to the equimolar ratio, the entropy value is more than or equal to 1.5R, and the B site is Co element.
  2. 2. The a-site defect-regulated high-entropy cobalt-based double perovskite solid oxide cathode material according to claim 1, wherein the a-site defect type derivative has a chemical formula (Gd 1/6 Pr 1/6 La 1/6 Ba 1/6 Sr 1/6 Ca 1/6 ) 0.93 CoO 3 .
  3. 3. The preparation method of the high-entropy cobalt-based double perovskite solid oxide cathode material with the A-site defect regulation is characterized by comprising the following specific steps of: (1) Stoichiometric ratio of a-site defective derivatives according to claim 1 or 2, weighing Gd 2 O 3 、Pr 6 O 11 、La 2 O 3 、BaCO 3 、SrCO 3 、CaCO 3 and Co (NO 3 ) 2 ·6H 2 O; (2) Dissolving Gd 2 O 3 in a dilute nitric acid solution, sequentially adding Pr 6 O 11 、La 2 O 3 、BaCO 3 、SrCO 3 、CaCO 3 and Co (NO 3 ) 2 ·6H 2 O, uniformly mixing, then adding a complexing agent, heating and stirring the mixed solution, cooling, adjusting the pH value to 7-8, continuously stirring, and heating to evaporate water to obtain gel; (3) Heating and drying the gel to obtain cathode precursor powder; (4) Sintering the cathode precursor powder to obtain the A-site defect type derivative, which is designated as (GPLBSC) 0.93 CO.
  4. 4. A method of preparation according to claim 3 wherein the complexing agent is citric acid and ethylenediamine tetraacetic acid.
  5. 5. The method according to claim 4, wherein the citric acid is 1.5 times the total mole number of the metal ions, and the ethylenediamine tetraacetic acid is 0.5 times the total mole number of the metal ions.
  6. 6. The preparation method according to claim 3, wherein in the step (2), the temperature is reduced to 90 ℃ after heating and stirring, the temperature is reduced to 40 ℃ after heating and stirring for 15min at constant temperature, and the stirring continuing time is 4h.
  7. 7. A method according to claim 3, wherein in step (4), the sintering is 1000 ℃ for 5 hours.
  8. 8. The application of the A-site defect-regulated high-entropy cobalt-based double perovskite solid oxide cathode material obtained by the preparation method according to any one of claims 3 to 7 is characterized in that the A-site defect-regulated high-entropy cobalt-based double perovskite solid oxide cathode material is used for an SOFC cathode or used as an electrocatalytic material for oxygen reduction/oxygen precipitation reactions of metal-air cells and water electrolysis cells and the electrocatalytic fields of carbon dioxide electroreduction and nitrogen reduction.

Description

High-entropy cobalt-based double perovskite solid oxide cathode material with A-site defect regulation and control function, and preparation method and application thereof Technical Field The invention relates to the technical field of Solid Oxide Fuel Cell (SOFC) cathode materials, in particular to a medium-low temperature adaptive type A-site defect control high-entropy cobalt-based double perovskite solid oxide fuel cell cathode material, and a preparation method and application thereof. Background The SOFC as a high-efficiency green energy conversion device has the core advantages of high energy conversion efficiency, wide fuel adaptability, environmental friendliness and the like, and is one of key technologies for coping with global energy crisis and environmental pollution. The electrochemical reaction core of the SOFC is concentrated at the three-phase interface of the cathode, the anode and the electrolyte, wherein the ORR of the cathode is a core bottleneck which restricts the improvement of the overall performance of the cell due to high activation energy and slow reaction dynamics, so that the development of a high-performance cathode material suitable for medium-low temperature operation is a key break-through for promoting the practical application of the SOFC. Perovskite type oxide (ABO 3) is a main flow research system of an SOFC cathode, and in order to break through the performance limitation of the traditional perovskite, the scientific research world gradually forms a multi-dimensional optimization path, wherein the traditional low-entropy perovskite such as La 1-xSrxMnO3-δ (LSM) has excellent stability but insufficient catalytic activity, and the mixed ion-electron conductor such as La 0.6Sr0.4Co0.2Fe0.8O3-δ (LSCF) has improved catalytic activity but poor thermal expansion coefficient and electrolyte suitability. In order to solve the contradiction, the related technology performs targeted exploration that CN200810055747.1 discloses La doped low-entropy perovskite cathode material ((Ba 0.5Sr0.5)1-xLaxCo0.8Fe0.2O3-δ), conductivity is improved through A-site double-element doping, but multi-element synergistic effect of a low-entropy system is limited and defect regulation is not involved, CN114744222A provides double-perovskite material (Ba 1-xGd0.8Pr0.2+xCo2O6-δ) with A-site proportion regulation, medium-low temperature stability is optimized, the material still belongs to a low-entropy structure, oxygen vacancy regulation depends on single-element proportion regulation, flexibility is insufficient, and CN119191372A designs single/double-perovskite composite recyclable cathode material (Ba 1.1(Gd0.8La0.2)0.9(Co1.5Fe0.5)O6-δ), focusing material recoverability is not concerned with depth optimization of ORR activity. In recent years, the high-entropy perovskite oxide shows unique advantages by virtue of disordered and uniform distribution of various cations at the A/B position, namely, the multielement synergistic effect can flexibly regulate and control lattice distortion, an electronic structure and oxygen vacancy concentration, and meanwhile, the thermal stability and chemical compatibility of the material are remarkably improved, so that the high-entropy perovskite oxide becomes an important research direction of SOFC cathode materials. Meanwhile, the A-site defect engineering is taken as a classical performance regulation strategy, and has been proved to be capable of inducing oxygen vacancy formation through cation deletion, improving oxygen ion conductivity and surface oxygen exchange capacity (such as entropy perovskite in A-site defect disclosed in CN117737767A, although the improvement effect of the defect on activity is verified, the core is applied to electrolytic water Oxygen Evolution Reaction (OER), and the entropy system cannot exert the containing and stabilizing effect of a high-entropy structure on the defect). However, the prior art does not realize the effective fusion of a high-entropy structure and a defect engineering, although patents such as CN201810459689, CN202510530878 and the like relate to A-site regulation, but focus on non-SOFC scenes such as NO catalytic oxidation, toluene catalytic oxidation and the like, the low-entropy double perovskite structure is not matched with the requirement of medium-low temperature ORR, most high-entropy perovskite researches only pay attention to structural stability, the defect engineering is not introduced to optimize the oxygen vacancy concentration, and the technology related to defects is mostly limited to a medium-low entropy system, and the problems of cation aggregation, phase separation and the like are easily caused after the defects are introduced. Currently, the following problems exist in the prior art: 1. The high entropy and defect cooperative regulation and control are absent, the activity and the stability are difficult to be compatible, the prior art is limited to element doping of a low entropy system, the