Search

CN-118874454-B - Modified indium oxide carbon composite material and preparation method thereof, and method for preparing methanol by carbon dioxide hydrogenation

CN118874454BCN 118874454 BCN118874454 BCN 118874454BCN-118874454-B

Abstract

The invention relates to the field of catalysts, and discloses a modified indium oxide carbon composite material, a preparation method thereof and a method for preparing methanol by hydrogenating carbon dioxide, wherein the preparation method comprises the following steps of (1) preparing a dispersion liquid containing indium salt, a modifier, a carbon source and water, wherein the modifier is zirconia with a monoclinic crystal form, (2) reacting the dispersion liquid in a supercritical state of water, and then carrying out heat treatment on an obtained product, wherein the mass ratio of the indium salt to the modifier calculated by oxide is 1-6:1. The invention adopts simple and efficient supercritical fluid deposition technology, leads the indium salt to reach an oversaturated state in supercritical solution instantly by introducing monoclinic zirconia as a modifier, forms a large number of crystal nuclei, can effectively control the crystal orientation of indium oxide, and prepares the modified indium oxide carbon composite material containing cubic indium oxide/hexagonal indium oxide mixed crystal, and the catalyst has good catalytic activity and stability.

Inventors

  • YAN ZHENNAN
  • LI HONGWEI
  • HOU JILI
  • SUN XIA
  • LIU YINGSHUO
  • HOU CHAOPENG

Assignees

  • 中国石油化工股份有限公司
  • 中石化石油化工科学研究院有限公司

Dates

Publication Date
20260505
Application Date
20230426

Claims (20)

  1. 1. The preparation method of the modified indium oxide carbon composite material is characterized by comprising the following steps of: (1) Preparing a dispersion liquid containing indium salt, a modifier, a carbon source and water; The modifier is zirconia with monoclinic crystal form; (2) In the supercritical state of water, the dispersion liquid is reacted, and then the obtained product is subjected to heat treatment; Wherein the mass ratio of the indium salt to the modifier is 1-6:1.
  2. 2. The preparation method according to claim 1, wherein the mass ratio of the indium salt and the modifier in terms of oxide is 1.5-3:1.
  3. 3. The production method according to claim 1, wherein a mass ratio of the total amount of the indium salt and the modifier in terms of oxide to the carbon source in the dispersion is 0.1 to 2:1.
  4. 4. The production method according to claim 3, wherein a mass ratio of the total amount of the indium salt and the modifier in terms of oxide to the carbon source in the dispersion is 0.2 to 1:1.
  5. 5. The production method according to claim 1 or 2, wherein the average crystal grain size of the modifier is 5 to 25nm.
  6. 6. The preparation method according to claim 5, wherein the average crystal grain size of the modifier is 10 to 18nm.
  7. 7. The process according to claim 1, wherein the concentration of the indium salt in the dispersion is 0.1 to 4mol/L.
  8. 8. The preparation method according to claim 1, wherein the indium salt is a soluble salt of indium, and the soluble salt is an inorganic salt and/or an organic salt.
  9. 9. The preparation method according to claim 8, wherein the soluble salt is at least one selected from nitrate, sulfate, acetate, chloride and metal alkoxide.
  10. 10. The production method according to claim 1, wherein the carbon source is at least one selected from sucrose, starch, glucose, maltose, cellulose, citric acid, maleic acid, fumaric acid, succinic acid, tartaric acid, malic acid, gluconic acid, terephthalic acid, ethylenediamine tetraacetic acid, dipicolinic acid and trimesic acid.
  11. 11. The production method according to claim 10, wherein the carbon source is at least one selected from sucrose, maleic acid, terephthalic acid, dipicolinic acid and tartaric acid.
  12. 12. The method according to claim 1, wherein the dispersion further contains an oxidizing agent.
  13. 13. The method of claim 12, wherein the oxidizing agent is H 2 O 2 .
  14. 14. The method of claim 12, wherein the oxidizing agent is provided in the form of a solution.
  15. 15. The production method according to claim 12, wherein the oxidizing agent is used in an amount of 0.001 to 1% by mass based on the total mass of the dispersion.
  16. 16. The process according to claim 15, wherein the oxidizing agent is used in an amount of 0.001 to 0.01wt% based on the total mass of the dispersion.
  17. 17. The preparation method according to claim 1, wherein in the step (2), the reaction conditions include a temperature of 400-600 ℃, a reaction pressure of 23-45MPa, and a reaction time of 1-200min.
  18. 18. The process according to claim 17, wherein in the step (2), the reaction conditions include a temperature of 400 to 520 ℃, a reaction pressure of 24 to 35MPa, and a reaction time of 20 to 150min.
  19. 19. The preparation method according to claim 1, wherein the heat treatment conditions include a temperature of 250-500 ℃ for 1-5 hours under an inert atmosphere.
  20. 20. The method according to claim 19, wherein the heat treatment conditions include a temperature of 350 to 420 ℃ for 1.5 to 3 hours.

Description

Modified indium oxide carbon composite material and preparation method thereof, and method for preparing methanol by carbon dioxide hydrogenation Technical Field The invention relates to the field of catalysts, in particular to a modified indium oxide carbon composite material, a preparation method thereof and a method for preparing methanol by carbon dioxide hydrogenation. Background Methanol is an important raw material for chemicals and a substitute for fossil fuels, and the preparation of methanol by reacting CO 2 with H 2 from renewable energy sources not only solves greenhouse gas control but also solves an effective way of fossil fuel substitution. In the reaction of preparing methanol by CO 2 hydrogenation, the most reported catalyst is a modified copper-based catalyst, and the Cu-based catalyst for preparing methanol by using the traditional synthesis gas has been widely studied in the process of preparing methanol by using carbon dioxide. However, for Cu-based catalysts, the further application is limited by the characteristics of high side Reaction (RWGS) activity, sintering of H 2 O-induced active phase, poor stability, etc. The high cost of noble metals and the low activity and mobility of ZnO in other catalytic systems also limit to some extent the further use of these catalysts in this field. In 2O3 has moderate CO 2 and CO adsorption capacity, shows methanol selectivity obviously superior to Cu, CO, noble metal catalysts, and has higher catalytic activity compared with ZnO catalysts, and thus has attracted extensive attention from scientific researchers. In the reaction of preparing methanol by CO 2 hydrogenation, the indium-based catalyst shows high methanol selectivity, but the CO 2 conversion rate is not high, and the design and development of a more effective modified indium oxide catalyst have great significance for industrial application of preparing methanol by CO 2 hydrogenation, and still face great challenges in spite of greatly improving the catalytic performance. Disclosure of Invention The invention aims to solve the problems of complex preparation process, poor repeatability and insufficient catalytic activity and stability of an indium oxide catalyst in the prior art, and provides a modified indium oxide carbon composite material, a preparation method thereof and a method for preparing methanol by carbon dioxide hydrogenation. In order to achieve the above object, the present invention provides a method for preparing a modified indium oxide carbon composite material, comprising the steps of: (1) Preparing a dispersion liquid containing indium salt, a modifier, a carbon source and water; The modifier is zirconia with monoclinic crystal form; (2) In the supercritical state of water, the dispersion liquid is reacted, and then the obtained product is subjected to heat treatment; Wherein the mass ratio of the indium salt to the modifier is 1-6:1. The second aspect of the invention provides a modified indium oxide carbon composite material prepared by the preparation method; the modified indium-carbon composite material comprises indium oxide, a modifying element and carbon, wherein the indium oxide comprises cubic-phase indium oxide and hexagonal-phase indium oxide, the modifying element at least partially exists in the form of zirconium oxide, the zirconium oxide has a monoclinic crystal form, and the mass ratio of the indium oxide to the modifying element calculated by oxide is 1.5-3:1. In a third aspect, the present invention provides a method for preparing methanol by hydrogenating carbon dioxide, the method comprising: And (2) contacting carbon dioxide with hydrogen in the presence of a catalyst under the condition of preparing methanol by hydrogenating the carbon dioxide, wherein the catalyst is the modified indium oxide carbon composite material in the second aspect. The invention adopts a simple and efficient supercritical fluid deposition technology, and leads the indium salt to reach an oversaturated state in a supercritical solution instantly by introducing monoclinic zirconia as a modifier, thus forming a large number of crystal nuclei, and being capable of effectively controlling the crystal orientation of the indium oxide, thus preparing the modified indium oxide carbon composite material containing cubic indium oxide/hexagonal indium oxide mixed crystal. Meanwhile, monoclinic phase zirconia is helpful for regulating and controlling the concentration of oxygen holes in the catalyst, and further improving the catalytic activity and stability of the catalyst. Drawings FIG. 1 is an X-ray diffraction pattern of the modified indium oxide carbon composite material prepared in example 1. Detailed Description The endpoints and any values of the ranges disclosed herein are not limited to the precise range or value, and are understood to encompass values approaching those ranges or values. For numerical ranges, one or more new numerical ranges may be found between the endpoints