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CN-121983601-A - Rhodium-praseodymium double-single-atom catalyst of nitrogen-doped carbon carrier limited domain, and preparation method and application thereof

CN121983601ACN 121983601 ACN121983601 ACN 121983601ACN-121983601-A

Abstract

The invention provides a rhodium-praseodymium double-single-atom catalyst of a nitrogen-doped carbon carrier limit, a preparation method and application thereof, wherein (1) Zn (NO 3 ) 2 ·6H 2 O, rh precursor and Pr precursor are dispersed in methanol to obtain a homogeneous solution A, (7-8) the molar ratio of Rh element to Pr element is (10-11), (2) 2-methylimidazole is dissolved in methanol to obtain a homogeneous solution B, (3) the homogeneous solution A and the homogeneous solution B are mixed and then react under pressure, the reaction product is centrifuged to obtain a first composite solid, (4) the first composite solid is washed and dried and then subjected to heat treatment to obtain a second composite solid, and (5) the second composite solid is subjected to acid washing, suction filtration, drying and grinding to obtain the rhodium-praseodymium double-single-atom catalyst of the nitrogen-doped carbon carrier limit, rhPr/NC double-single-atom catalyst shows excellent hydroxylation property and long-term CO poisoning stability under an acidic condition.

Inventors

  • GE JUNJIE
  • WEI KAI
  • ZHANG SIXIANG

Assignees

  • 中国科学技术大学

Dates

Publication Date
20260505
Application Date
20260206

Claims (10)

  1. 1.A preparation method of a rhodium-praseodymium double single-atom catalyst of a nitrogen-doped carbon carrier limited domain comprises the following steps: (1) Dispersing Zn (precursor of NO 3 ) 2 ·6H 2 O, rh and precursor of Pr) in methanol to obtain a homogeneous solution A, wherein the molar ratio of Rh element to Pr element is (10-11): 7-8; (2) Dissolving 2-methylimidazole in methanol to obtain a homogeneous solution B; (3) Mixing the homogeneous solution A and the homogeneous solution B, then reacting under pressure, and centrifuging a reaction product to obtain a first composite solid; (4) Washing the first composite solid, and performing heat treatment after drying to obtain a second composite solid; (5) And carrying out acid washing, suction filtration, drying and grinding on the second composite solid to obtain the rhodium-praseodymium double-single-atom catalyst suitable for the limiting field of the nitrogen-doped carbon carrier for resisting CO poisoning of the anode of the proton exchange membrane fuel cell.
  2. 2. The preparation method according to claim 1, wherein the temperature of the heat treatment is 900-1000 ℃ and the time is 55-65 min; The atmosphere of the heat treatment was a mixed atmosphere of H 2 and Ar.
  3. 3. The process according to claim 1, wherein the pressurized reaction is carried out in an autoclave; the temperature of the pressurizing reaction is 115-125 ℃ and the time is 3.5-4.5 h.
  4. 4. The preparation method of claim 1, wherein the mass-to-volume ratio of the 2-methylimidazole to the methanol is (0.65-0.66) g/15 mL.
  5. 5. The production method according to claim 1, wherein the precursor of Rh is Rh (acac) 3 ; Pr precursor is PrCl 3 ·7H 2 O.
  6. 6. The preparation method according to claim 5, wherein the mass-volume ratio of Zn (NO 3 ) 2 ·6H 2 O、Rh(acac) 3 、PrCl 3 ·6H 2 O) to methanol in the step (1) is (0.59-0.60) g (53-54) mg (34.5-35.5) mg (7-8) mL.
  7. 7. The preparation method of the acid cleaning agent according to claim 1, wherein the acid used for the acid cleaning is perchloric acid, the concentration of the perchloric acid is 0.09-0.111 mol/L, and the time of the acid cleaning agent is 11-13 h.
  8. 8. The method according to claim 1, wherein the suction filtration in step (5) is performed using ultra-pure water-washed filter cake; the drying temperature is 55-65 ℃ and the drying time is 11-13 h.
  9. 9. A rhodium-praseodymium diatomic catalyst of nitrogen doped carbon support confinement prepared by the preparation method of any one of claims 1-8.
  10. 10. An application of a rhodium-praseodymium diatomic catalyst of nitrogen doped carbon carrier limited domain prepared by the preparation method of any one of claims 1-8 in the anode anti-CO poisoning of proton exchange membrane fuel cell.

Description

Rhodium-praseodymium double-single-atom catalyst of nitrogen-doped carbon carrier limited domain, and preparation method and application thereof Technical Field The invention belongs to the technical field of catalysts, and particularly relates to a rhodium-praseodymium double-single-atom catalyst of a nitrogen-doped carbon carrier limited domain, and a preparation method and application thereof. Background The hydrogen energy is used as secondary energy with high energy density and zero carbon emission, and is an important direction for realizing global energy structure transformation. The fuel cell is an important application outlet of hydrogen energy as a novel power generation technology capable of directly converting chemical energy into electric energy with high efficiency. Proton Exchange Membrane Fuel Cells (PEMFCs) are considered to be one of the core technologies for future clean energy transportation and distributed power sources due to their low operating temperature, high energy conversion efficiency, and fast dynamic response capability. Currently, the anode side of the PEMFC can only use expensive high-purity hydrogen as fuel, but cannot use inexpensive crude hydrogen containing a small amount of CO, which limits the popularization of the PEMFC in terms of cost. This is because the adsorption strength of CO on the active sites of the catalyst (e.g., pt, rh, etc.) is extremely high, and CO in H 2 preferentially occupies the reactive sites on the catalyst, thus blocking the adsorption of H 2 to the catalyst (1 ppm CO in H 2 can result in a surface blocking rate of over 90%), resulting in a greatly suppressed HOR process. The CO molecules provide electrons to the empty orbitals of the metal through the 4 sigma and 5 sigma orbitals, and form firm chemical adsorption bonds (Pt-CO, rh-CO and the like) along with pi reverse bond orbitals of the metal d orbitals to CO, so that active sites are occupied and difficult to desorb, and the output power and durability of the battery are obviously reduced. Therefore, designing a catalytic center with lower CO adsorption energy is an ideal approach to solve this problem. At the same time, since water is also a reactant for CO electrooxidation, a specific catalytic site is required that is capable of activating water at a sufficiently low potential. However, currently available catalysts have not met these stringent requirements. For example, the best CO-tolerant catalysts PtRu/C to date require high Pt usage (> 0.4 mg cm -2) to provide specific cell performance in the presence of CO, which runs in the opposite direction of the cost reduction requirements of the technology. To ameliorate the above problems, researchers have proposed various regulatory strategies such as constructing bimetallic alloys or developing monoatomic catalysts (SACs). The monoatomic catalyst can greatly improve the utilization rate of atoms and effectively regulate and control the electronic structure of the monoatomic catalyst by anchoring metal atoms on a carrier in an atomically dispersed form. However, single-atom catalysts still present a significant challenge in efficiently catalyzing the Hydrogen Oxidation Reaction (HOR) because hydrogen dissociation generally requires adjacent two-site synergy. Under the background, a single-atom catalyst capable of simultaneously and efficiently and stably catalyzing HOR and CO electrooxidation reaction (COOR) is developed, so that the full activation of CO and H 2 O under low potential is realized, and the catalyst has important research value and application prospect. Disclosure of Invention In view of the above, the present invention aims to provide a rhodium-praseodymium double monoatomic catalyst of nitrogen doped carbon carrier limited domain, a preparation method and application thereof, wherein the RhPr/NC double monoatomic catalyst prepared by the method shows excellent HOR activity and long-term CO poisoning resistance stability under an acidic condition. The invention provides a preparation method of a rhodium-praseodymium double single-atom catalyst of a nitrogen-doped carbon carrier limited domain, which comprises the following steps: (1) Dispersing Zn (precursor of NO 3)2·6H2 O, rh and precursor of Pr) in methanol to obtain a homogeneous solution A, wherein the molar ratio of Rh element to Pr element is (10-11): 7-8; (2) Dissolving 2-methylimidazole in methanol to obtain a homogeneous solution B; (3) Mixing the homogeneous solution A and the homogeneous solution B, then reacting under pressure, and centrifuging a reaction product to obtain a first composite solid; (4) Washing the first composite solid, and performing heat treatment after drying to obtain a second composite solid; (5) And carrying out acid washing, suction filtration, drying and grinding on the second composite solid to obtain the rhodium-praseodymium double-single-atom catalyst suitable for the limiting field of the nitrogen-doped carbon carrier for resisting CO