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KR-20260065360-A - A copper-nickel dual atom catalyst that selectively produces CO by electrochemically reducing CO2

KR20260065360AKR 20260065360 AKR20260065360 AKR 20260065360AKR-20260065360-A

Abstract

The present invention relates to a copper-nickel diatomaceous catalyst that selectively produces CO by electrochemically reducing CO2 , and more specifically, to a copper- nickel diatomaceous catalyst in which the electrical conductivity and catalytic activity per atom of the catalyst in the electrode are maximized in the CO2 reduction reaction, thereby improving the current density by 2.7 times compared to a single-atom catalyst and having a CO selectivity of 95% or more.

Inventors

  • 김현탁
  • 박민주
  • 유영우
  • 박지훈
  • 이진희
  • 김상준
  • 김민철
  • 신재호
  • 김경민

Assignees

  • 한국화학연구원

Dates

Publication Date
20260508
Application Date
20241101

Claims (13)

  1. In a copper-nickel dual atomic catalyst that electrochemically reduces CO2 to selectively produce CO, The above-mentioned dual-atom catalyst is characterized by the fact that the active metals copper and nickel are dispersed as dual atoms in a nitrogen-doped carbon material. Copper-nickel diatomaceous catalyst that electrochemically reduces CO2 to selectively produce CO.
  2. In the above paragraph 1, Characterized by the fact that the molar ratio of copper to nickel in the copper-nickel diatomaceous atomic catalyst is in the range of 0.7:1 to 5:1. Copper-nickel diatomaceous catalyst that electrochemically reduces CO2 to selectively produce CO.
  3. In paragraph 1, The copper-nickel diatomaceous catalyst is characterized by being obtained by thermally decomposing a catalyst precursor dispersion, in which a mixture comprising a copper organometallic compound and colloidal silica is dispersed in an organic solvent, after raising the temperature under an inert gas atmosphere. Copper-nickel diatomaceous catalyst that electrochemically reduces CO2 to selectively produce CO.
  4. In paragraph 3, The copper organometallic compound and the nickel organometallic compound are characterized by containing any one of phthalocyanine, porphyrin, and porphyrazine in their structure. Copper-nickel diatomaceous catalyst that electrochemically reduces CO2 to selectively produce CO.
  5. In paragraph 1, The above nitrogen-doped carbon material is characterized by being in the form of a two-dimensional carbon body, Copper-nickel diatomaceous catalyst that electrochemically reduces CO2 to selectively produce CO.
  6. A method for producing a copper-nickel diatomaceous atomic catalyst that selectively generates CO by electrochemically reducing CO2 , (a) a step of providing a catalyst precursor dispersion in which a mixture comprising a copper organometallic compound, a nickel organometallic compound, and colloidal silica is dispersed in an organic solvent; (b) a step of removing the solvent from the catalyst precursor dispersion to a predetermined level; (c) a step of obtaining a pyrolysis product by heating the catalyst precursor dispersion after step (b) at a rate of 2.0 to 4.5 ℃/min to a pyrolysis temperature under an inert gas atmosphere and then pyrolyzing for a predetermined time; and (d) a step of obtaining a diatomaceous catalyst in which copper-nickel diatomaceous atoms are dispersed on a nitrogen-doped carbon material by removing colloidal silica from the pyrolysis product above; characterized by including, Method for preparing a copper-nickel diatomaceous catalyst that selectively produces CO by electrochemically reducing CO2 .
  7. In paragraph 6, The copper organometallic compound and the nickel organometallic compound of step (a) above are characterized by containing any one of phthalocyanine, porphyrin, and porphyrazine in their structure. Method for preparing a copper-nickel diatomaceous catalyst that selectively produces CO by electrochemically reducing CO2 .
  8. In paragraph 6, The organic solvent of step (a) above is characterized by being a mixture of ethanol and DMF with a relative volume ratio of ethanol per unit volume of DMF (ethanol/DMF) in the range of 0.2 to 5. Method for preparing a copper-nickel diatomaceous catalyst that selectively produces CO by electrochemically reducing CO2 .
  9. In paragraph 6, The removal of the solvent in step (b) above is characterized by being performed such that the ratio of the solvent in the dispersion is in the range of 5 to 15 wt%, Method for preparing a copper-nickel diatomaceous catalyst that selectively produces CO by electrochemically reducing CO2 .
  10. In paragraph 6, The pyrolysis of step (c) above is characterized by being performed at a temperature in the range of 600 to 900 ℃. Method for preparing a copper-nickel diatomaceous catalyst that selectively produces CO by electrochemically reducing CO2 .
  11. In a method for producing CO from CO2 , Characterized by selectively producing CO by electrochemically performing a CO2 reduction reaction in the presence of a catalyst according to any one of claims 1 to 5, Method for producing CO from CO2 .
  12. In Paragraph 11, The above electrochemical CO2 reduction reaction is characterized by being carried out in an environment of a main electrolyte KHCO3 and a supporting electrolyte K2SO4 . Method for producing CO from CO2 .
  13. A CO2 electroreduction system comprising a CO2 electroreduction catalytic electrode comprising a copper-nickel diatomaceous atomic catalyst according to any one of claims 1 to 5.

Description

A copper-nickel dual atom catalyst that selectively produces CO by electrochemically reducing CO2 The present invention relates to a copper-nickel diatomaceous catalyst that electrochemically reduces CO2 to selectively produce CO, and more specifically, to a copper-nickel diatomaceous catalyst in which the electrical conductivity and catalytic activity per atom of the catalyst in the electrode are maximized in the CO2 reduction reaction, thereby improving the current density and having excellent selectivity for CO, the reaction product. Due to existing fossil fuel-based power generation systems, global warming and ocean acidification are continuously intensifying as CO2 emissions and dissolved CO2 concentrations in seawater increase , threatening the Earth's ecosystem. Consequently, research on electrocatalysts that convert CO2 into industrial raw materials, going beyond mere CO2 reduction, has been ongoing since 1869; however, high energy is required for chemical conversion due to CO2 's highly stable chemical structure and its tendency to repel electrons and holes. To overcome this, as advancements in sophisticated quantum calculation methods and the implementation and synthesis of electrocatalyst structures have been made, the core reaction of CO2 conversion has been identified as carboxylation, leading to research on high-performance metal (Cu, Pt, Au, Ag, Mo, Pd, Co, Pb, Sn, Ce)-based nanoparticles, metal oxides, and MOF (Metal-Oranic-Framework)-based electrocatalysts. The above electrocatalyst provides an activation site for converting CO2 by an electron-deficient metal-center or an electron-rich diatomic species, and can electrochemically convert CO2 into industrial raw materials such as carbon monoxide, methane, methanol, and formic acid by applying an external voltage. However, most electrocatalyst research uses expensive rare metals, and due to the limitations in the productivity (current density) of CO2 conversion products, there is a continuous demand for high-performance electrocatalysts. Accordingly, a single-atom catalyst (SAC) containing a single atom in a single-atom form was proposed as a novel electrocatalyst for electrochemically reducing CO2 , and research and development were conducted on electrocatalysts containing non-precious transition metals as active metals. In relation to the above electrocatalysts, Non-Patent Literature 1 discloses a Ni-SAC electrocatalyst in which nickel is bonded to a nitrogen atom doped in carbon black in the presence of urea, and Non-Patent Literature 2 discloses a Cu-SAC synthesized by carbonizing Na2 [Cu(EDTA)] and having CuN2O2 active sites formed therein . However, although the above SAC has shown remarkable performance, it has been pointed out that there is a limitation in that it is difficult to increase the concentration (area ratio density) of the active site as structural stability decreases as the catalytic active site becomes smaller at the atomic level. Accordingly, dual atom catalysts (DACs) are currently being researched and developed, which have heteroatom active sites and possess a stable bonding structure based on multiple activities, and have the advantage of improving binding energy through d-band center shifting between active atoms. Top-down and bottom-up methods are known for manufacturing the above-mentioned DAC. An example of the top-down method is a method in which a multilayered support, such as graphite, is exfoliated into a single layer, and then a metal is doped into the single layer of the support using ligands. There is an example in Chinese Patent Publication 115094442 A (published September 23, 2022) in which nitrogen ligands and metal precursors are introduced into graphene, which serves as the support. While the top-down method has the advantage of being similar to conventional methods of supporting metal on a support, it is difficult to control the dispersion of the doped metal, which can lead to the problem of the metal existing in a cluster form rather than atomic units. On the other hand, the above bottom-up method can be exemplified by a method in which a precursor included in the structure is introduced together with other support materials and then converted into a monolayer matrix form through thermal, chemical, or electrical treatment. There is an example in non-patent literature 3 (Dazhi Yao et al. (2023)) in which a DAC for CO2 reduction reaction with a metal supported on a graphene nanosheet is prepared by mixing a metal precursor and support materials, such as dicyandiamide and glucose, followed by heat treatment. This bottom-up method has the advantage of easily solving the metal dispersibility problem of the top-down method. Currently, the development of DAC is in its very early stages, and as the types of metal precursors and support materials applicable to the bottom-up method of manufacturing DAC and the characteristics of the catalysts produced therefrom are not well known, there is a need for research a