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CN-121988325-A - Cobaltosic oxide/carbon composite catalyst, preparation method thereof and application thereof in aldehyde/ketone hydrogenation reduction

CN121988325ACN 121988325 ACN121988325 ACN 121988325ACN-121988325-A

Abstract

The invention belongs to the technical field of catalytic chemistry and chemical industry, and relates to a cobaltosic oxide/carbon composite catalyst, a preparation method thereof and application thereof in aldehyde/ketone hydrogenation reduction. Adding cobalt salt and urea into a mixed solution of polyol and water, uniformly mixing, then carrying out solvothermal reaction to obtain a Co 2 (OH) 2 CO 3 precursor, and carrying out reduction calcination on the Co 2 (OH) 2 CO 3 precursor under a reducing and inert mixed atmosphere to obtain the catalyst. Experiments show that the Co 3 O 4 /C catalyst can efficiently catalyze aldehyde/ketone hydrodeoxygenation reaction under milder conditions, and the controllable preparation of the self-supporting single-component oxide surface H 2 activation and C-O bond rupture dual-function catalyst is realized.

Inventors

  • LIU SHULIN
  • ZHOU GUOWEI
  • LIU GUANGHAN
  • ZHAO RUSONG

Assignees

  • 齐鲁工业大学(山东省科学院)

Dates

Publication Date
20260508
Application Date
20241101

Claims (10)

  1. 1. A preparation method of a cobaltosic oxide/carbon composite catalyst is characterized by adding cobalt salt and urea into a mixed solution of polyol and water, uniformly mixing, then carrying out solvothermal reaction to obtain a Co 2 (OH) 2 CO 3 precursor, and carrying out reduction calcination on the Co 2 (OH) 2 CO 3 precursor under a reducing and inert mixed atmosphere to obtain the catalyst.
  2. 2. The method for preparing a tricobalt tetraoxide/carbon composite catalyst according to claim 1, wherein the molar ratio of cobalt salt to urea is 1:0.3-3.0, preferably 1:1.0-3.0, more preferably 1:1.5-2.5, even more preferably 1:1.8-2.2. The volume ratio of the polyol to the water is 1:0.5-1.5, preferably 1:0.9-1.1.
  3. 3. The method for preparing the cobaltosic oxide/carbon composite catalyst according to claim 1, wherein cobalt salt is added into water and mixed uniformly to obtain a cobalt salt aqueous solution, urea is added into polyalcohol and mixed uniformly to obtain a urea polyalcohol solution, the cobalt salt aqueous solution and the urea polyalcohol solution are mixed uniformly and then subjected to solvothermal reaction, and preferably the concentration of the cobalt salt aqueous solution is 0.3-1 mol/L, and preferably the concentration of the urea polyalcohol solution is 0.3-1 mol/L.
  4. 4. The method for preparing the cobaltosic oxide/carbon composite catalyst according to claim 1, wherein the solvothermal reaction is carried out at a temperature of 150-200 ℃ for 3-8 hours, preferably 4.5-5.5 hours.
  5. 5. The method for preparing a cobaltosic oxide/carbon composite catalyst according to claim 1, wherein the solvent-thermal reaction is followed by centrifugal separation, washing and drying, and then reduction calcination.
  6. 6. The method for preparing a cobaltosic oxide/carbon composite catalyst according to claim 1, wherein the volume fraction of the reducing gas is 5-15%, preferably 9-11% in the mixed atmosphere of reduction and inertness; Or, the reduction calcination temperature is 200 to 550 ℃, preferably 300 to 350 ℃.
  7. 7. The method for preparing a tricobalt tetraoxide/carbon composite catalyst according to claim 1, wherein the reduction calcination time is 0.1-6 h, preferably 1.5-2.5 h.
  8. 8. A tricobalt tetraoxide/carbon composite catalyst, characterized in that it is obtained by the preparation method according to any one of claims 1 to 7.
  9. 9. Use of the tricobalt tetraoxide/carbon composite catalyst according to claim 8 in aldehyde/ketone hydrogenation reduction.
  10. 10. The use according to claim 9, wherein the aldehyde/ketone is one or more of benzaldehyde, p-methylbenzaldehyde, p-hydroxybenzaldehyde, 3, 5-dimethylbenzaldehyde, 3-methyl-4-hydroxybenzaldehyde, acetophenone; Or the hydrogenation reduction reaction condition is that the temperature is 135-145 ℃, the pressure of H 2 is 2.5-3.5 MPa, and the reaction time is 6-8 hours; Or, in the hydrogenation reduction reaction, tetrahydrofuran, methanol, isopropanol, n-hexane and 1, 4-dioxane are used as the solvent, and isopropanol is preferable.

Description

Cobaltosic oxide/carbon composite catalyst, preparation method thereof and application thereof in aldehyde/ketone hydrogenation reduction Technical Field The invention belongs to the technical field of catalytic chemistry and chemical industry, and relates to a cobaltosic oxide/carbon composite catalyst, a preparation method thereof and application thereof in aldehyde/ketone hydrogenation reduction. Background The disclosure of this background section is only intended to increase the understanding of the general background of the invention and is not necessarily to be construed as an admission or any form of suggestion that this information forms the prior art already known to those of ordinary skill in the art. Hydrodeoxygenation reactions are very important in the upgrading of oxygenates in the petrochemical industry. So far, the catalytic hydrodeoxygenation reaction still adopts noble metal catalysts, such as Ru1/mpg-C3N4、10Pd/C、Pd/Al2O3、Au/Co3O4NRs-OVs and the like. Hydrogen activation is a key step in catalytic hydrogenation reactions, where noble metals have an unmatched advantage. However, the expensive price restricts the large-scale application of noble metal catalysts. The development of non-noble metal catalysts is particularly urgent. Many Co-based catalysts have been reported to be capable of carrying out hydrodeoxygenation reactions, such as supported metal or alloy catalysts like CoNi/Al 2O3、Co@NC、Cox P@POP. However, these systems generally have the problems of harsh reaction conditions, agglomeration of metal nanoparticles, easy oxidation and deactivation, etc. Therefore, there is a need to develop a highly selective, highly active oxide catalyst. Disclosure of Invention In order to solve the defects in the prior art, the invention aims to provide a cobaltosic oxide/carbon composite catalyst, a preparation method thereof and application thereof in aldehyde/ketone hydrogenation reduction. Experiments show that the Co 3O4/C catalyst can efficiently catalyze aldehyde/ketone hydrodeoxygenation reaction under milder conditions, and the controllable preparation of the self-supporting single-component oxide surface H 2 activation and C-O bond rupture bifunctional catalyst is realized. In order to achieve the above purpose, the technical scheme of the invention is as follows: According to the preparation method of the cobaltosic oxide/carbon composite catalyst, cobalt salt and urea are added into a mixed solution of polyalcohol and water, the mixture is uniformly mixed, then solvothermal reaction is carried out to obtain a Co 2(OH)2CO3 precursor, and the Co 2(OH)2CO3 precursor is subjected to reduction calcination in a mixed atmosphere of reduction and inertia, so that the catalyst is obtained. According to the preparation method, polyol is used as a structure guiding agent, urea is used as a precipitating agent, a semitransparent gel-like solid Co 2(OH)2CO3 precursor is prepared by a solvothermal method, the precursor can be calcined to obtain flaky Co 3O4/C, and self-supporting Co 3O4 particles, namely independent metal active centers, can be formed on the surface of flaky Co 3O4/C by reducing and calcining the precursor, so that an H 2 activation site and an adsorption site for hydrodeoxygenation of a reactant are constructed. According to the invention, the self-supporting Co 3O4 particles are formed on the surface of the flaky Co 3O4/C, so that agglomeration of Co 3O4 particles can be avoided, and the stability of an H 2 activation site and an adsorption site of hydrodeoxygenation of a reactant is ensured, thereby improving the activity stability of the catalyst. Experiments show that the Co 3O4/C catalyst prepared by the invention can efficiently catalyze aldehyde/ketone hydrodeoxygenation reaction under milder conditions. In a second aspect, a tricobalt tetraoxide/carbon composite catalyst is obtained by the above preparation method. In a third aspect, the use of the above-described tricobalt tetraoxide/carbon composite catalyst in the hydrogenation reduction of aldehydes/ketones. The beneficial effects of the invention are as follows: According to the invention, urea is taken as a precipitator, polyol is taken as a structure directing agent, a Co 2(OH)2CO3 precursor is prepared by a solvothermal method, and then reduction calcination is carried out, so that flaky Co 3O4/C can be formed, self-supporting Co 3O4 particles can be formed on the surface of flaky Co 3O4/C, and an H 2 activation site and an adsorption site for hydrodeoxygenation of a reactant are constructed. Experiments show that the flaky Co 3O4/C catalyst can efficiently catalyze the hydrodeoxygenation reaction of aldehyde/ketone under milder conditions, the conversion rate of catalytic substrate hydrodeoxygenation can be close to 100%, and the yield of the hydroquinone prepared by catalyzing the hydrogenation of parahydroxybenzaldehyde can be more than 99.0%. The preparation method provided by the invention has the advantages th