CN-121976212-A - Preparation method and application of copper-based nano-catalyst modified nano-pore electro-catalytic ceramic membrane

CN121976212ACN 121976212 ACN121976212 ACN 121976212ACN-121976212-A

Abstract

The invention discloses a preparation method and application of a copper-based nano-catalyst modified nano-pore electro-catalytic functional ceramic membrane, and belongs to the technical field of electro-catalytic membrane synthesis. The invention aims to solve the problems of low reactant diffusion efficiency and low active site utilization caused by uneven pore size distribution of a catalytic membrane layer and random mass transfer paths in the conventional electrocatalytic membrane. 1. Preparing casting solution, preparing a porous ceramic substrate, preparing a conductive ceramic substrate, preparing a phenolic resin prepolymer, preparing a conductive porous membrane layer precursor solution modified by a copper-based nano catalyst, spin-coating on the surface of the conductive ceramic substrate, drying and calcining. The application of the catalyst is used for synthesizing a C 2+ product by CO 2 RR, synthesizing NH 3 by NO 3 RR and synthesizing urea by C-N coupling.

Inventors

LUO XINSHENG
XU ZHE
ZHENG BINGYU
JIANG YUNXIN
CHENG XIAOXIANG
ZHANG ZHIBIN
WU DAOJI
LI RONGCHEN
CHEN FEIYONG

Assignees

山东建筑大学

Dates

Publication Date: 20260505
Application Date: 20260209

Claims (10)

1. The preparation method of the copper-based nano catalyst modified nano pore canal electro-catalytic functional ceramic membrane is characterized by comprising the following steps of: 1. dissolving polyvinyl alcohol in ultrapure water, adding Al 2 O 3 and TiO 2 into the polyvinyl alcohol solution, ball-milling, and finally vacuum defoaming to obtain a casting solution; 2. Spin-coating the casting solution on the upper surface of the ceramic membrane and drying, and then repeating spin-coating and drying for a plurality of times to obtain a spin-coated ceramic membrane substrate, and calcining the spin-coated ceramic membrane substrate at a high temperature to obtain a pore channel ceramic substrate; 3. dispersing Ti 4 O 7 and carbon powder in a polyvinyl butyral solution, spin-coating the solution on the upper surface of a porous ceramic substrate, drying, repeating spin-coating and drying for a plurality of times, and finally reducing at a high temperature to obtain a conductive ceramic substrate; 4. Dissolving phenol in a sodium hydroxide solution, adding formaldehyde solution, reacting under heating and stirring conditions, adjusting pH to be neutral after the reaction, and finally drying under vacuum conditions to remove water to obtain a phenolic resin prepolymer; 5. dissolving a phenolic resin prepolymer and PEO-PPO-PEO template agent in tetrahydrofuran solution to obtain a conductive pore canal layer precursor solution, and then adding a copper-based nano catalyst into the conductive pore canal layer precursor solution to obtain a conductive pore canal membrane layer precursor solution modified by the copper-based nano catalyst; the copper-based nano catalyst is a Cu nano catalyst, a CuCo nano alloy catalyst or a CuCoZn nano alloy catalyst; 6. Spin-coating a copper-based nano-catalyst modified conductive pore canal membrane layer precursor solution on the upper surface of a conductive ceramic substrate, drying, and calcining to obtain a copper-based nano-catalyst modified nano-pore canal electrocatalytic functional ceramic membrane; When the copper-based nano catalyst is a Cu nano catalyst, the prepared nano pore electro-catalytic functional ceramic membrane modified by the copper-based nano catalyst is a pore electro-catalytic ceramic membrane modified by the Cu nano catalyst; When the copper-based nano catalyst is a CuCo nano alloy catalyst, the prepared nano pore electro-catalytic functional ceramic membrane modified by the copper-based nano catalyst is a pore electro-catalytic ceramic membrane modified by the CuCo nano alloy catalyst; When the copper-based nano catalyst is CuCoZn nano alloy catalyst, the prepared nano pore electro-catalytic ceramic membrane modified by the copper-based nano catalyst is a pore electro-catalytic ceramic membrane modified by CuCoZn nano alloy catalyst.
2. The preparation method of the copper-based nano-catalyst modified nano-pore electro-catalytic ceramic membrane is characterized by comprising the steps of firstly dissolving polyvinyl alcohol into ultrapure water under the conditions of boiling water and stirring speed of 100 rpm-200 rpm, adding Al 2 O 3 and TiO 2 into the polyvinyl alcohol solution, then ball milling for 1 h-2 h under the conditions of ball mass ratio of 1 (0.5-0.7) and rotating speed of 200 rpm-500 rpm, and finally vacuum defoaming for 10 min-20 min, wherein the mass ratio of the polyvinyl alcohol to the Al 2 O 3 is 1 (10-20), the mass ratio of the polyvinyl alcohol to the TiO 2 is 1 (5-10), the particle size of the Al 2 O 3 is 4 mu m-6 mu m, the particle size of the TiO 2 is 100 nm-300 nm.
3. The preparation method of the copper-based nano catalyst modified nano pore channel electro-catalytic functional ceramic membrane is characterized in that in the second step, casting solution is spin-coated on the upper surface of an alumina ceramic membrane at the rotation speed of 500-1000 rpm, the alumina ceramic membrane is dried in an oven with the temperature of 45-55 ℃ in 30-40 min after spin-coating, spin-coating and drying are repeated for 5-6 times to obtain a spin-coated ceramic membrane substrate, the spin-coated ceramic membrane substrate is calcined at the high temperature of 1000-1500 ℃ for 3-5 h to obtain the pore channel ceramic substrate, the ratio of the single-coating dropping volume of the casting solution to the coating area of the alumina ceramic membrane in the second step is (0.5-1) mL:1cm 2 , and the diameter of the ceramic membrane in the second step is 2 cm-5 cm.
4. The preparation method of the copper-based nano catalyst modified nano pore electro-catalytic ceramic membrane is characterized in that Ti 4 O 7 and carbon powder are dispersed in a polyvinyl butyral solution in the third step to obtain a Ti 4 O 7 /carbon powder casting solution, the Ti 4 O 7 /carbon powder casting solution is spin-coated on the upper surface of a pore ceramic substrate at the speed of 1500 rpm-2000 rpm, the pore ceramic substrate is dried at the temperature of 70 ℃ to 80 ℃, spin-coating and drying are repeated for 2 times to 3 times, finally the mixed atmosphere of Ar/H 2 and the temperature of 400 ℃ to 700 ℃ are reduced for 2H to 3H to obtain a conductive ceramic substrate, the volume ratio of Ar to H 2 in the mixed atmosphere of Ar/H 2 is (8-9): 1, the single coating drop volume of the Ti 4 O 7 /carbon powder casting solution in the third step is (0.3-0.5) mL, the coating area ratio of the pore ceramic substrate is 3-0.5), the mass ratio of the polyvinyl butyral solution in the step is the polyvinyl butyral solution in the step of 531 to the polyvinyl butyral is the polyvinyl butyral solution in the step of 20 ℃ to the step of 20 ℃, and the mass ratio of the polyvinyl butyral solution in the step of 20 [ 50 ] is the polyvinyl butyral solution in the mixed atmosphere of Ar/H 2 is (8-9) [1 ].
5. The preparation method of the copper-based nano catalyst modified nano pore electro-catalytic functional ceramic membrane is characterized in that phenol is dissolved in a sodium hydroxide solution under the condition of a stirring speed of 500-1000 rpm, formaldehyde solution is added, the reaction is carried out for 30-60 min under the condition of a temperature of 50-80 ℃ and a stirring speed of 500-1000 rpm, pH is regulated to be neutral by hydrochloric acid with a concentration of 0.5-1M after the reaction, finally moisture is removed by drying under the conditions of vacuum and a temperature of 50-80 ℃ to obtain a phenolic resin prepolymer, the mass ratio of the phenol to the sodium hydroxide solution is 1 (100-200), the mass ratio of the formaldehyde solution to the sodium hydroxide solution is 1 (100-200), the mass percentage of the sodium hydroxide solution is 10-30%, and the mass percentage of the formaldehyde solution is 30-40%.
6. The preparation method of the copper-based nano catalyst modified nano pore canal electro-catalytic functional ceramic membrane is characterized in that the Cu nano catalyst in the fifth step is prepared by mixing Cu (acac) 2 , ascorbic acid and oleylamine ultrasonically, heating in an oil bath, and finally centrifugally collecting, wherein the molar ratio of Cu (acac) 2 to ascorbic acid is 1 (3-4), and the volume ratio of Cu (acac) 2 to oleylamine is 1mol (0.25-0.5) mL; the CuCo nano alloy catalyst is prepared by the following steps of carrying out ultrasonic mixing on Cu (acac) 2 、Co(acac) 2 , ascorbic acid and oleylamine, heating in an oil bath, and finally centrifugally collecting, wherein the molar ratio of Cu (acac) 2 to Co (acac) 2 is 1 (1-2), the molar ratio of Cu (acac) 2 to ascorbic acid is 1 (3-4), and the volume ratio of Cu (acac) 2 to oleylamine is 1mol (0.25-0.5) mL; The CuCoZn nanometer alloy catalyst in the fifth step is specifically prepared by the steps of mixing Cu (acac) 2 、Co(acac) 2 、Zn(acac) 2 , ascorbic acid and oleylamine in an ultrasonic manner, heating in an oil bath, and finally centrifugally collecting to obtain the CuCoZn nanometer alloy catalyst, wherein the molar ratio of Cu (acac) 2 to Co (acac) 2 is 1 (1-2), the molar ratio of Cu (acac) 2 to Zn (acac) 2 is 1 (1-2), the molar ratio of Cu (acac) 2 to ascorbic acid is 1 (3-4), and the volume ratio of Cu (acac) 2 to oleylamine is 1mol (0.25-0.5) mL.
7. The preparation method of the copper-based nano catalyst modified nano pore canal electro-catalytic functional ceramic membrane is characterized in that ultrasonic mixing is carried out for 30-60 min under the condition that the power is 100-200W, oil bath heating is carried out for 4-6 h under the condition that the temperature is 150-250 ℃, and centrifugal collection is carried out at the rotating speed of 10000rpm~15000 rpm.
8. The preparation method of the copper-based nano catalyst modified nano pore canal electro-catalytic functional ceramic membrane is characterized in that the mass ratio of phenolic resin prepolymer to PEO-PPO-PEO template agent in the step five is 1 (2-3), the mass ratio of phenolic resin prepolymer to tetrahydrofuran solution in the step five is 1 (4-6), and the mass ratio of phenolic resin prepolymer to copper-based nano catalyst in the step five is 1 (1-2).
9. The preparation method of the copper-based nano catalyst modified nano pore electro-catalytic functional ceramic membrane according to claim 1 is characterized in that in the sixth step, under the condition that the rotating speed is 3000-4000 rpm, the copper-based nano catalyst modified conductive pore membrane precursor solution is spin-coated on the upper surface of a conductive ceramic substrate for 2-3 times, firstly, under the condition that the temperature is 50-60 ℃, the copper-based nano catalyst modified conductive pore membrane precursor solution is dried for 10-20 hours, then under the condition that the temperature is 100-120 ℃, the copper-based nano catalyst modified conductive pore membrane precursor solution is dried for 10-20 hours, and then the copper-based nano catalyst modified nano pore electro-catalytic functional ceramic membrane is obtained by calcining for 2-4 hours under the condition that the mixed atmosphere of Ar/H 2 and the temperature is 450-600 ℃, wherein the volume ratio of Ar to H 2 in the mixed atmosphere of Ar/H 2 is (8-9): 1, and the single coating volume of the copper-based nano catalyst modified conductive pore membrane precursor solution to the conductive ceramic substrate is coated with the volume of 370.35-6 mL.
10. The application of the copper-based nano-catalyst modified nano-pore electro-catalytic ceramic membrane is characterized in that the Cu-based nano-catalyst modified pore electro-catalytic ceramic membrane is used for synthesizing a C 2+ product from CO 2 RR, the CuCo nano-alloy catalyst modified pore electro-catalytic ceramic membrane is used for synthesizing NH 3 from NO 3 RR, and the CuCoZn nano-alloy catalyst modified pore electro-catalytic ceramic membrane is used for synthesizing urea from C-N coupling.

Description

Preparation method and application of copper-based nano-catalyst modified nano-pore electro-catalytic ceramic membrane Technical Field The invention belongs to the technical field of electrocatalytic membrane synthesis. Background Along with the transformation of energy structures and the aggravation of environmental problems, the utilization of electrocatalytic technology to realize the recycling transformation of carbon-containing and nitrogen-containing substances becomes a research hot spot. Carbon dioxide (CO 2) and bicarbonate (HCO 3-) are used as important inorganic carbon sources, and the electrocatalytic reaction of the carbon dioxide can generate carbon-containing compounds such as carbon monoxide, formic acid, ethylene, ethanol and the like, so that the carbon dioxide has important significance in the aspect of carbon recycling. Meanwhile, the electrocatalytic reduction of nitrogen-containing pollutants such as nitrate can generate ammonia or further be coupled with an activated carbon intermediate to generate urea, so that the high-value utilization of nitrogen is realized. Therefore, the construction of the electrocatalytic system with both carbon source and nitrogen source conversion capability is of great significance for realizing high-nitrogen and high-carbon wastewater treatment and sustainable synthesis of multi-carbon compounds, ammonia and urea. The existing electrocatalytic research mostly adopts planar metal or carbon-based electrodes, has limited reaction interface and low mass transfer efficiency, is difficult to simultaneously meet the requirements of multiple electron transfer reactions on reactant supply, electron transfer and intermediate stability, and particularly has severely limited reaction efficiency and product selectivity in the electrosynthesis process using KHCO 3、CO2 and a mixed system thereof as reactants. In addition, the traditional electrode is easy to corrode, inactivate or be unstable in structure under the conditions of high current density and complex electrolysis, and the universality and long-term operation capability of the traditional electrode in the multi-system electrocatalytic synthesis reaction are restricted. The electrocatalytic ceramic membrane is used as a novel electrode material with a nano pore structure and excellent chemical stability, and can enhance the flowing process of electrolyte in the filtering process and improve the mass transfer efficiency and the electron utilization rate. By introducing a conductive intermediate layer into the ceramic pore canal framework and loading different types of metal nano alloy catalysts on the surface of the ceramic pore canal framework, multi-path electrocatalytic conversion of CO 2、HCO3- and nitrate nitrogen (NO 3-) can be realized. However, the existing electrocatalytic membrane has the problems of uneven pore size distribution and random mass transfer paths, which seriously results in low reactant diffusion efficiency and insufficient active site utilization rate. This greatly limits its use in electrocatalytic synthesis of multi-carbon (C 2+) products, ammonia (NH 3) and urea. Disclosure of Invention The invention solves the problems of low reactant diffusion efficiency and low active site utilization caused by uneven pore size distribution and random mass transfer paths of a catalytic membrane layer in the traditional electrocatalytic membrane, and further provides a preparation method and application of a copper-based nano-catalyst modified nano-pore electrocatalytic functional ceramic membrane. The preparation method of the copper-based nano catalyst modified nano pore canal electro-catalytic functional ceramic membrane comprises the following steps: 1. dissolving polyvinyl alcohol in ultrapure water, adding Al 2O3 and TiO 2 into the polyvinyl alcohol solution, ball-milling, and finally vacuum defoaming to obtain a casting solution; 2. Spin-coating the casting solution on the upper surface of the ceramic membrane and drying, and then repeating spin-coating and drying for a plurality of times to obtain a spin-coated ceramic membrane substrate, and calcining the spin-coated ceramic membrane substrate at a high temperature to obtain a pore channel ceramic substrate; 3. dispersing Ti 4O7 and carbon powder in a polyvinyl butyral solution, spin-coating the solution on the upper surface of a porous ceramic substrate, drying, repeating spin-coating and drying for a plurality of times, and finally reducing at a high temperature to obtain a conductive ceramic substrate; 4. Dissolving phenol in a sodium hydroxide solution, adding formaldehyde solution, reacting under heating and stirring conditions, adjusting pH to be neutral after the reaction, and finally drying under vacuum conditions to remove water to obtain a phenolic resin prepolymer; 5. dissolving a phenolic resin prepolymer and PEO-PPO-PEO template agent in tetrahydrofuran solution to obtain a conductive pore canal layer precursor solution, and the