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CN-117920305-B - FexM/RGO catalyst reinforced by carbon quantum dots and preparation method and application thereof

CN117920305BCN 117920305 BCN117920305 BCN 117920305BCN-117920305-B

Abstract

The invention provides a carbon quantum dot enhanced Fe x M/RGO catalyst, a preparation method and application thereof, and relates to the technical field of catalysts and carbon dioxide hydrogenation. The Fe x M/RGO catalyst with the enhanced carbon quantum dots comprises reduced graphene oxide, nitrogen-doped carbon quantum dots embedded into the surface of the reduced graphene oxide, and active component Fe x M nano-particles anchored on the surface and bulk phase of the reduced graphene oxide, wherein M in the Fe x M nano-particles is one or more of C, N and P, and x is 2-16. The invention effectively improves the stability of the Fe-based catalyst and the selectivity of the target product C 8 ～C 16 based on the synergistic effect of the components. The catalyst provided by the invention has excellent performance, is used for catalyzing CO 2 to prepare aviation kerosene by hydrogenation, can promote the reaction, has high CO 2 conversion rate and high selectivity of the target product C 8 ～C 16 component.

Inventors

  • CHEN JIANGANG
  • ZHANG JUAN

Assignees

  • 中国科学院山西煤炭化学研究所

Dates

Publication Date
20260505
Application Date
20240118

Claims (10)

  1. 1. A carbon quantum dot enhanced Fe x M/RGO catalyst comprises reduced graphene oxide, nitrogen doped carbon quantum dots embedded in the surface of the reduced graphene oxide, and active component Fe x M nano particles anchored on the surface and bulk phase of the reduced graphene oxide, wherein M in the Fe x M nano particles is one or more of C, N and P, and x is 2-16; The preparation method of the carbon quantum dot reinforced Fe x M/RGO catalyst comprises the following steps: (1) Mixing a carbon source, a nitrogen source and a solvent for a first hydrothermal reaction to obtain a nitrogen-doped carbon quantum dot; (2) Mixing the nitrogen-doped carbon quantum dots, graphene oxide, water and ferric salt, adjusting the pH value of the obtained mixed solution to 8.0-12.0, and then performing a second hydrothermal reaction to obtain a catalyst precursor; (3) And carrying out heat treatment on the catalyst precursor in the presence of a non-metal source to obtain the Fe x M/RGO catalyst reinforced by the carbon quantum dots, wherein the non-metal source comprises one or more of a carbon source, a nitrogen source and a phosphorus source.
  2. 2. The carbon quantum dot reinforced Fe x M/RGO catalyst according to claim 1, wherein the mass ratio of the reduced graphene oxide, the nitrogen doped carbon quantum dot and the Fe x M nano-particles is (15-90): (0.5-10): (3-90).
  3. 3. The carbon quantum dot enhanced Fe x M/RGO catalyst as claimed in claim 1 or 2, wherein the reduced graphene oxide surface and bulk phase are further anchored with an alkali metal oxide, the alkali metal oxide comprises potassium oxide and/or sodium oxide, and the mass ratio of alkali metal element to reduced graphene oxide in the alkali metal oxide is (0.05-10): 15-90.
  4. 4. The preparation method of the carbon quantum dot reinforced Fe x M/RGO catalyst as claimed in any one of claims 1-2, which is characterized by comprising the following steps: (1) Mixing a carbon source, a nitrogen source and a solvent for a first hydrothermal reaction to obtain a nitrogen-doped carbon quantum dot; (2) Mixing the nitrogen-doped carbon quantum dots, graphene oxide, water and ferric salt, adjusting the pH value of the obtained mixed solution to 8.0-12.0, and then performing a second hydrothermal reaction to obtain a catalyst precursor; (3) And carrying out heat treatment on the catalyst precursor in the presence of a non-metal source to obtain the Fe x M/RGO catalyst reinforced by the carbon quantum dots, wherein the non-metal source comprises one or more of a carbon source, a nitrogen source and a phosphorus source.
  5. 5. The preparation method of the carbon-containing beverage of claim 4, wherein the carbon source in the step (1) is one or more of glucose, citric acid, tartaric acid, malonic acid, lactose and lactic acid, the nitrogen source is one or more of ethylenediamine, urea, ammonia water, biuret, phenylenediamine, glycine, tryptophan and arginine, and the mass ratio of the carbon source to the nitrogen source is 1:1-100:1.
  6. 6. The method according to claim 4, wherein the pH in the step (2) is adjusted by adding an inorganic base including one or more of ammonia, sodium and potassium.
  7. 7. The method according to claim 4, wherein the carbon source in the step (3) comprises one or more of CO, CO 2 、C 2 H 2 、CH 4 and C 2 H 4 , the nitrogen source comprises NH 3 , and the phosphorus source comprises one or more of white phosphorus, red phosphorus, PH 3 and sodium hypophosphite.
  8. 8. The preparation method according to claim 4, wherein the temperature of the first hydrothermal reaction is 100-230 ℃ and the time is 6-48 hours, the temperature of the second hydrothermal treatment is 120-240 ℃ and the time is 4-48 hours, and the temperature of the heat treatment is 200-900 ℃ and the time is 4-24 hours.
  9. 9. The carbon quantum dot reinforced Fe x M/RGO catalyst according to any one of claims 1-3 or the application of the carbon quantum dot reinforced Fe x M/RGO catalyst prepared by the preparation method according to any one of claims 4-8 in preparing aviation kerosene by CO 2 hydrogenation.
  10. 10. The use according to claim 9, wherein the feed gas for producing aviation kerosene by hydrogenating CO 2 comprises CO 2 and H 2 , the molar ratio of CO 2 to H 2 in the feed gas is 1.0-5.0:1, the space velocity of the feed gas is 3-50L/g cat /H, the reaction temperature is 250-350 ℃, and the reaction pressure is 1-6 MPa.

Description

FexM/RGO catalyst reinforced by carbon quantum dots and preparation method and application thereof Technical Field The invention relates to the technical field of catalysts and carbon dioxide hydrogenation, in particular to a carbon quantum dot enhanced Fe x M/RGO catalyst, a preparation method and application thereof. Background The aviation kerosene as fuel for aviation turbine engine has the advantages of proper density, high heat value, good combustion performance, less carbon deposit, good low-temperature fluidity, good heat stability and oxidation stability, high cleanliness, less corrosion to machine parts, etc., and is suitable for gas turbine engine and ramjet engine, and widely used in civil and military aviation aircrafts. Unlike other vehicles, current aviation kerosene cannot be replaced by new energy power due to the special requirements of aviation engines on energy density and weight of fuel. Aviation kerosene mainly comprises hydrocarbon compounds with carbon number of C 8～C16, the current source mainly comprises petroleum refining products, and the aviation kerosene can also be obtained through coal liquefaction technology, natural gas liquefaction and biomass liquefaction. Carbon dioxide (CO 2) is a greenhouse gas, and with the development of industry, fossil fuels such as coal, oil and natural gas are used in large quantities, so that the emission amount of carbon dioxide gas is increased year by year. The increase of carbon dioxide emission increases the global warming speed and obviously damages the global ecological environment, so that the emission reduction, the storage and the utilization of carbon dioxide are research subjects commonly faced by scientists in various countries at present. The recycling of CO 2 is an important way to realize carbon reduction. Because of the chemical inertness of CO 2, the hydroconversion of CO 2 into compounds containing more than two carbon atoms is difficult. The hydrogenation of carbon dioxide to hydrocarbons typically uses iron-based catalysts to produce longer chain hydrocarbons by continuous catalytic reverse water gas reactions, as well as fischer-tropsch reactions. However, the iron-based catalyst is easy to break particles during the reaction process, so that the reaction is stopped, and in addition, under the partial pressure that a large amount of water is generated during the reaction process of higher CO 2 and H 2O(CO2, the iron-based catalyst is easy to oxidize, so that the catalyst is deactivated. In general, the existing catalyst for synthesizing aviation kerosene by CO 2 hydrogenation still faces the challenges of low product selectivity and poor catalyst stability. Disclosure of Invention In view of the above, the invention aims to provide a carbon quantum dot reinforced Fe x M/RGO catalyst, and a preparation method and application thereof. The Fe x M/RGO catalyst with enhanced carbon quantum dots provided by the invention has good stability, and can realize high-selectivity synthesis of aviation kerosene by direct hydrogenation of CO 2. In order to achieve the above object, the present invention provides the following technical solutions: The invention provides a carbon quantum dot enhanced Fe x M/RGO catalyst, which comprises reduced graphene oxide, nitrogen doped carbon quantum dots embedded into the surface of the reduced graphene oxide, and active component Fe x M nano particles anchored on the surface and bulk phase of the reduced graphene oxide, wherein M in the Fe x M nano particles is one or more of C, N and P, and x is 2-16. Preferably, the mass ratio of the reduced graphene oxide to the nitrogen-doped carbon quantum dots to the Fe x M nano-particles is (15-90): 0.5-10): 3-90. Preferably, the surface and the bulk phase of the reduced graphene oxide are also anchored with alkali metal oxides, the alkali metal oxides comprise potassium oxide and/or sodium oxide, and the mass ratio of alkali metal elements in the alkali metal oxides to the reduced graphene oxide is (0.05-10): 15-90. The invention provides a preparation method of the carbon quantum dot reinforced Fe x M/RGO catalyst, which comprises the following steps: (1) Mixing a carbon source, a nitrogen source and a solvent for a first hydrothermal reaction to obtain a nitrogen-doped carbon quantum dot; (2) Mixing the nitrogen-doped carbon quantum dots, graphene oxide, water and ferric salt, adjusting the pH value of the obtained mixed solution to 8.0-12.0, and then performing a second hydrothermal reaction to obtain a catalyst precursor; (3) And carrying out heat treatment on the catalyst precursor in the presence of a non-metal source to obtain the Fe x M/RGO catalyst reinforced by the carbon quantum dots, wherein the non-metal source comprises one or more of a carbon source, a nitrogen source and a phosphorus source. Preferably, the carbon source in the step (1) is one or more of glucose, citric acid, tartaric acid, malonic acid, lactose and lactic acid, the nitrogen