CN-121553979-B - Low-crystalline tin dioxide catalyst for electrocatalysis and preparation method thereof

Abstract

The invention belongs to the technical field of electrocatalysis, and particularly relates to a low-crystalline tin dioxide catalyst for electrocatalysis and a preparation method thereof. The preparation of the low-crystalline tin dioxide is realized by regulating and controlling factors such as solute types, solvent proportions and the like and adopting a simple one-step precipitation method. The low-crystalline catalyst contains abundant crystalline-amorphous heterogeneous interfaces and defects (such as oxygen vacancies), enhances carbon dioxide adsorption and activation, improves formic acid selectivity and catalytic reaction activity, maintains high Faraday efficiency under industrial-grade current density, and overcomes the problems of poor stability, aggravation of hydrogen evolution side reaction and the like of the traditional SnO 2 catalyst under high current. In addition, the method does not need high-temperature calcination, has low energy consumption, uses common reagents, and is suitable for industrial large-scale preparation. The low crystalline tin dioxide exhibits excellent activity and selectivity in the electrocatalytic reduction of CO 2 to formic acid.

Inventors

• XIE WENFU
• LI BINGKUN
• WANG QIANG

Assignees

• 北京林业大学

Dates

Publication Date

20260512

Application Date

20260123

Claims (1)

1. 1. The use of a low crystalline tin dioxide catalyst in electrocatalysis characterized in that the method for preparing the low crystalline tin dioxide catalyst comprises the following steps: S1, mixing tin salt with a solvent A according to a proportion of 1mmol (0-10) mL and with an endpoint value not being 0, and stirring 300-500 rpm until the tin salt is completely dissolved to obtain a substance 1, wherein the tin salt is any one of stannic chloride and a hydrate thereof; s2, adding a solvent B into the substance 1, and continuing to stir for 20-40min at 300-500 rpm to obtain a substance 2, wherein the ratio of the tin salt to the solvent B is 1mmol (0-10) mL and the endpoint value is not 0; the ratio of the total addition amount of the solvent A and the solvent B to the tin salt is (3-10) mL, namely 1 mmol, and the volume ratio of the solvent A to the solvent B is 1:1 respectively; S3, adding an alkaline solution into the substance 2, and keeping stirring for 0.5-1.5h after observing that white precipitate is generated, so as to obtain a substance 3, wherein the alkaline solution is ammonia water or potassium hydroxide solution, the ratio of tin salt to ammonia water is 1mmol (0-4) mL and the endpoint value is not 0, the ratio of the amount of the substances of potassium hydroxide in the tin salt to the amount of the substances of potassium hydroxide in the potassium hydroxide solution is 1mmol (0-4) mmol and the endpoint value is not 0; S4, sequentially washing the substance 3 with absolute ethyl alcohol and deionized water, centrifuging for 5-6 times or vacuum filtering, and vacuum drying for 5-12 hours under the conditions that the vacuum degree is 0.08-0.1 MPa and the temperature is 50-80 ℃.

Description

Low-crystalline tin dioxide catalyst for electrocatalysis and preparation method thereof Technical Field The invention belongs to the technical field of electrocatalysis, and particularly relates to a low-crystalline tin dioxide catalyst for electrocatalysis and a preparation method thereof. Background With the large-scale use of fossil energy sources such as coal, oil, and natural gas, the human society starts to enter a high-speed development period. However, fossil energy generates a large amount of carbon dioxide (CO 2) to be discharged into the atmosphere in the process of being utilized, so that environmental problems such as global warming and seawater acidification are increasingly serious, and the sustainable development of human society is seriously threatened. Currently, carbon dioxide capture utilization and sequestration (CCUS) is receiving widespread attention as an effective way to reduce CO 2 emissions. The electrocatalytic CO 2 reduction technology which is one of the CO 2 utilization technologies can be used for electrochemically converting CO 2 into high-added-value fuels and chemicals by taking renewable electric energy as an energy source, has the advantages of mild reaction conditions, controllable process and the like, and has great development potential. Electrocatalytic CO 2 reduction products are numerous, such as carbon monoxide, formic acid, ethylene, ethanol, and the like. The formic acid can be used as chemical raw materials, fuel cell raw materials and the like, has wide market prospect, and has higher added value compared with other products. Tin dioxide (SnO 2) is a common catalyst for producing formic acid by CO 2 reduction by electrocatalysis, and the catalyst has the advantages of high selectivity of producing formic acid, low price, environmental friendliness and the like, but also has the problems of poor stability, aggravation of hydrogen evolution reaction and the like under large current (more than or equal to 300 and mA cm -2) of industrial grade. Several studies have shown that compared with catalysts with high crystallinity, low-crystalline catalysts possess more abundant active sites due to high density of defects and unsaturated coordination environments, and have stronger adsorption and activation capacities for CO 2. Thus, the low crystalline catalyst has a higher electrocatalytic CO 2 reduction potential. The development of a low-crystalline tin dioxide catalyst which is efficient and suitable for industrial large-scale preparation is beneficial to the industrial application of the technology of producing formic acid by pushing the electrocatalytic CO 2 to reduce. Disclosure of Invention The invention aims to provide a low-crystalline tin dioxide catalyst for electrocatalysis and a preparation method thereof, which show excellent activity and selectivity in the reduction of electrocatalytic CO 2 to produce formic acid. A method for preparing a low crystalline tin dioxide catalyst for electrocatalysis, comprising the steps of: s1, mixing tin salt with a solvent A, and stirring 300-500 rpm until the tin salt is completely dissolved to obtain a substance I; S2, adding a solvent B into the first substance, and continuing to stir 300-500 rpm for 20-40min to obtain a second substance; S3, adding an alkaline solution into the substance II, observing that white precipitate is generated, and then keeping stirring for 0.5-1.5h at 300-500 rpm to obtain a substance III; s4, sequentially washing the three-purpose absolute ethyl alcohol and deionized water, centrifuging for 5-6 times (or vacuum suction filtration), and vacuum drying to obtain the three-purpose absolute ethyl alcohol. Preferably, in the step S1, the tin salt is any one of tin chloride and a hydrate thereof. Preferably, in the step S1, the solvent a is absolute ethanol or deionized water. Preferably, the ratio of the tin salt to the solvent A is 1mmol (0-10) mL. Preferably, in the step S2, the solvent B is absolute ethanol or deionized water. Preferably, the ratio of the tin salt to the solvent B is 1mmol (0-10) mL. Preferably, the ratio of the total addition amount of the solvent A and the solvent B to the tin salt is (3-10) mL, 1 mmol. In some preferred embodiments, solvent A and solvent B are ethanol and deionized water, respectively, in a 1:1 volume ratio. Preferably, in the step S3, the alkaline solution is one or more of ammonia water, sodium hydroxide solution and potassium hydroxide solution. Preferably, the mass fraction of the ammonia water is 28-30%, and the molar concentration of the sodium hydroxide solution and the potassium hydroxide solution can be 0.1-10 mol/L. Preferably, the ratio of the tin salt to the ammonia water is 1mmol (0-4) mL. Preferably, the ratio of the amount of the tin salt to the amount of sodium hydroxide in the sodium hydroxide solution is 1 mmol (0-4) mmol, and the ratio of the amount of the tin salt to the amount of potassium hydroxide in the potassium hydroxide solution