CN-122006739-A - Method for preparing porous medium catalyst by synergy of ultrasonic atomization and in-situ joule heating

CN122006739ACN 122006739 ACN122006739 ACN 122006739ACN-122006739-A

Abstract

The invention discloses a method for preparing a porous medium catalyst by synergy of ultrasonic atomization and in-situ Joule heating, which comprises the steps of adopting nitric acid solution to remove impurities and etch a microporous structure of a porous medium material, adopting conductive suspension to treat the porous medium material to form a functional porous medium carrier with a conductive path, connecting conductive electrodes at two ends of the functional porous medium carrier, placing the functional porous medium carrier into a reaction cavity, starting an ultrasonic atomizer to atomize a precursor solution into micron-sized liquid drops, guiding the micron-sized liquid drops to the surface of the carrier, applying direct current or alternating current voltage to the electrodes while atomizing, and naturally cooling to room temperature under inert atmosphere after the reaction is completed, thus obtaining the porous medium catalyst. According to the method, the conductive functionalization enables the insulating carrier to have Joule heating capacity, precursor liquid drops are deposited on the surface of the conductive functionalization carrier, and the uniform feeding of ultrasonic atomization is combined, so that the integrated process of deposition, namely pyrolysis, is realized, the preparation time is obviously shortened, the energy consumption is reduced, and the load uniformity and the active phase dispersity are improved.

Inventors

Lin Beilong
DING JIAMIN
XU XINLEI
LU SHENGYONG
WANG GUANJIE
TANG MINGHUI
PENG YAQI
HAN ZHENGDONG
WU YUJIA
ZHOU BING
ZHU HUIPING

Assignees

浙江大学台州研究院
浙江大学

Dates

Publication Date: 20260512
Application Date: 20251222

Claims (10)

1. The method for preparing the porous medium catalyst by combining ultrasonic atomization and in-situ Joule heating is characterized by comprising the following steps of: S1, placing a porous medium material in a nitric acid solution, performing hydrothermal treatment to remove surface impurities and etch a microporous structure, taking out, alternately washing with ethanol and deionized water to be neutral, and drying; S2, adding one or more soluble transition metal salts serving as active metal sources into deionized water or absolute ethyl alcohol, and uniformly stirring to prepare a precursor solution; S3, placing the functionalized porous medium carrier obtained in the step S1 into a reaction cavity, starting an ultrasonic atomizer, atomizing the precursor solution in the step S2 into micron-sized liquid drops, and guiding the micron-sized liquid drops to the surface of the functionalized porous medium carrier through carrier gas; S4, stopping power supply and atomization, and naturally cooling the functionalized porous medium carrier to room temperature in an inert atmosphere to obtain the porous medium catalyst; the porous dielectric material is one or more of ceramic, cordierite and silicon carbide.
2. The method for preparing a porous medium catalyst according to claim 1, wherein in step S1, the conductive suspension is one or more of a carbon nanotube dispersion, a graphene slurry, a conductive polymer dispersion, and a metal nanowire dispersion.
3. The method for preparing the porous medium catalyst by combining ultrasonic atomization and in-situ Joule heating according to claim 1, wherein in the step S1, the mass concentration of the nitric acid solution is 5% -15%.
4. The method for preparing the porous medium catalyst by combining ultrasonic atomization and in-situ Joule heating according to claim 1, wherein in the step S1, the hydrothermal treatment temperature is 60-80 ℃ and the treatment time is 2-4 hours.
5. The method for preparing the porous medium catalyst by combining ultrasonic atomization and in-situ joule heating according to claim 1, wherein in the step S2, the concentration of the precursor solution is 0.1-1 mol/L.
6. The method for preparing a porous medium catalyst by combining ultrasonic atomization and in-situ joule heating according to claim 1, wherein in the step S2, the active metal source is one or more of cobalt nitrate, manganese nitrate, copper acetate, cerium nitrate and ferric chloride.
7. The method for preparing the porous medium catalyst by synergy of ultrasonic atomization and in-situ joule heating according to claim 1, wherein in the step S2, a complexing agent is further added into the precursor solution, and the complexing agent is one or more of citric acid, tartaric acid and ethylenediamine tetraacetic acid.
8. The method for preparing the porous medium catalyst by synergy of ultrasonic atomization and in-situ joule heating according to claim 1, wherein the molar ratio of the active metal source to the complexing agent is 1 (0.8-2).
9. The method for preparing the porous medium catalyst by combining ultrasonic atomization and in-situ joule heating according to claim 1, wherein in the step S3, the carrier gas is nitrogen or air, and the flow is 0.5-3L/min.
10. The method for preparing a porous medium catalyst by combining ultrasonic atomization and in-situ joule heating according to claim 1, wherein in the step S3, the effective voltage of applying the direct current or alternating current voltage is 5-20V, and the application time is 30-180 seconds.

Description

Method for preparing porous medium catalyst by synergy of ultrasonic atomization and in-situ joule heating Technical Field The invention belongs to the technical field of catalytic material preparation, and particularly relates to a method for preparing a porous medium catalyst by cooperation of ultrasonic atomization and in-situ joule heating. Background The catalytic oxidation technology is regarded as one of the most promising terminal treatment technologies because of the advantages of high efficiency, energy saving, less secondary pollution and the like. The core of the technology is a high-performance catalytic material, wherein the porous medium catalytic material is widely applied in the field of catalysts due to the high specific surface area, good diffusion performance and adjustable pore structure. However, how to achieve uniform dispersion of active sites in porous media to improve catalytic efficiency and stability is still one of the research hotspots in this field. Disclosure of Invention In order to solve the problems of long catalyst preparation period, high energy consumption and uneven load in the prior art, the invention provides a method for preparing a porous medium catalyst by combining ultrasonic atomization and in-situ Joule heating. The method combines the ultrasonic atomization and in-situ Joule heating technology to realize the efficient and uniform loading of the active components by carrying out functionalization treatment on the porous medium carrier. In order to achieve the above purpose, the invention adopts the following technical means: the first aspect of the invention provides a method for preparing a porous medium catalyst by combining ultrasonic atomization and in-situ Joule heating, which comprises the following steps: S1, placing a porous medium material in a nitric acid solution, performing hydrothermal treatment to remove surface impurities and etch a microporous structure, taking out, alternately washing with ethanol and deionized water to be neutral, and drying; S2, adding one or more soluble transition metal salts serving as active metal sources into deionized water or absolute ethyl alcohol, uniformly stirring, and preparing to obtain a precursor solution; S3, placing the functionalized porous medium carrier obtained in the step S1 into a reaction cavity, starting an ultrasonic atomizer, atomizing the precursor solution in the step S2 into micron-sized liquid drops, guiding the micron-sized liquid drops to the surface of the functionalized porous medium carrier through carrier gas, applying direct current or alternating current voltage to electrodes at two ends of the functionalized porous medium carrier while atomizing, enabling current to pass through the carrier to generate Joule heat, enabling the surface temperature of the current to be quickly increased to 200-600 ℃, and enabling the precursor liquid drops contacted with the surface of the carrier to instantaneously evaporate the solvent and generate thermal decomposition to generate metal oxide nano particles in situ and be attached to the inner wall of a pore canal; And S4, stopping power supply and atomization after the reaction is finished, and naturally cooling the functionalized porous medium carrier to room temperature under inert atmosphere to obtain the porous medium catalyst. In some embodiments of the invention, in step S1, the porous dielectric material is one or more of ceramic, cordierite, and silicon carbide. In some embodiments of the invention, in step S1, the conductive suspension is one or more of a carbon nanotube dispersion, a graphene slurry, a conductive polymer dispersion, or a metal nanowire dispersion. In some embodiments of the invention, in step S1, the nitric acid solution has a mass concentration of 5% -15%. In some embodiments of the invention, in step S1, the hydrothermal treatment temperature is 60-80 ℃ and the treatment time is 2-4 hours. In some embodiments of the present invention, in step S2, the precursor solution concentration is 0.1 to 1mol/L. In some embodiments of the invention, in step S2, the active metal source is one or more of cobalt nitrate, manganese nitrate, copper acetate, cerium nitrate, ferric chloride. In some embodiments of the present invention, in step S2, a complexing agent is further added to the precursor solution, where the complexing agent is one or more of citric acid, tartaric acid, and ethylenediamine tetraacetic acid. In some embodiments of the invention, the molar ratio of the active metal source to the complexing agent is 1 (0.8-2). In some embodiments of the invention, in step S3, the carrier gas is nitrogen or air at a flow rate of 0.5-3L/min. In some embodiments of the invention, in step S3, the effective voltage for applying the direct or alternating voltage is 5-20V for 30-180 seconds. In a second aspect, the invention provides a porous media catalyst prepared by the method of the first aspect. The third aspect of the invention provi