阅读说明：本技术 一种二氧化钛修饰的活性炭负载银单原子催化剂及其在氧化甲醛中的应用 (Titanium dioxide modified activated carbon supported silver monatomic catalyst and application thereof in formaldehyde oxidation ) 是由 高秀姣 其他发明人请求不公开姓名 于 2019-09-26 设计创作，主要内容包括：本发明涉及一种二氧化钛修饰的活性炭负载银单原子催化剂及其在氧化甲醛中的应用,包括活性炭的预处理、二氧化钛修饰的活性炭载体的制备和二氧化钛修饰的活性炭负载银单原子的制备三个步骤,得到一种二氧化钛修饰的活性炭负载银单原子催化剂。与现有技术相比,本发明以二氧化钛修饰的活性炭为载体,银单原子形貌特征呈均匀规则,并且在室温下对甲醛具有良好的催化性能和稳定性,并且制备工艺简单,适于产业化生产,具有较高的经济价值。(The invention relates to a titanium dioxide modified activated carbon silver-loaded monatomic catalyst and application thereof in formaldehyde oxidation. Compared with the prior art, the invention takes the titanium dioxide modified active carbon as the carrier, the shape and the feature of the silver monoatomic atom are uniform and regular, the catalyst has good catalytic performance and stability to formaldehyde at room temperature, and the preparation process is simple, suitable for industrial production and has higher economic value.)

1. A titanium dioxide modified activated carbon supported silver monatomic catalyst and application thereof in formaldehyde oxidation, the method comprises the following steps:

(1) pretreatment of activated carbon

The active carbon is stirred in strong oxidant solution at a controlled temperature for reaction, cooled to room temperature, filtered, washed, dried in vacuum, sealed and stored;

(2) Preparation of titanium dioxide modified activated carbon carrier

weighing pretreated active carbon, adding the active carbon into a titanium dioxide solution, and carrying out constant-temperature ultrasonic oscillation to obtain a suspension of the titanium dioxide modified active carbon carrier;

(3) Preparation of titanium dioxide modified activated carbon loaded with silver monoatomic atom

dissolving a titanium dioxide modified activated carbon carrier, a stabilizing agent and a silver precursor in deionized water, slowly adding a reducing agent solution at a low temperature, reacting, washing for multiple times, and drying in vacuum to obtain the titanium dioxide modified activated carbon loaded silver monoatomic atom.

2. the method for preparing the titanium dioxide modified activated carbon loaded with silver monatomic according to claim 1, wherein the strong oxidant in step (1) is any one or a combination of more of ammonium persulfate, concentrated nitric acid, potassium permanganate and concentrated sulfuric acid.

3. The method for preparing the titanium dioxide modified activated carbon loaded with silver monoatomic atoms according to claim 1, wherein the temperature in the step (1) is 40 ℃ to 190 ℃, and the mass ratio of the oxidizing agent to the activated carbon is 0.1% to 5000%.

4. the method for preparing the titanium dioxide modified activated carbon loaded with silver monoatomic atoms according to claim 1, wherein the mass ratio of the activated carbon to the titanium dioxide in the step (2) is 0.9% -900%, the constant temperature is 20 ℃ to 90 ℃, and the ultrasonic oscillation time is 1 minute to 300 minutes.

5. the method for preparing the titanium dioxide modified activated carbon loaded with silver monoatomic ions according to claim 1, wherein the stabilizer in the step (3) is any one or more of ascorbic acid, sodium citrate, aqueous vinyl acetate, acrylic ester, ethylenediaminetetraacetic acid, tributyl citrate, disodium ethylenediaminetetraacetate, tetrasodium ethylenediaminetetraacetate, and sodium iron ethylenediaminetetraacetate.

6. The method for preparing a titanium dioxide-modified activated carbon-supported silver monoatomic salt according to claim 1, wherein the silver precursor in the step (3) is any one or more of silver nitrate, silver thiocyanate, silver iodide, silver carbonate, silver tetrafluoroborate, silver hexafluoroantimonate, silver phosphate, silver bis (trifluoromethanesulfonyl) imide, silver acetylacetonate, silver lactate, silver sulfadiazine, silver trifluoroacetate, silver sulfide, silver acetate, silver trifluoromethanesulfonate, silver metavanadate, silver pentafluoropropionate, silver methanesulfonate, and silver p-toluenesulfonate.

7. The method for preparing the titanium dioxide modified activated carbon loaded with silver monatomic according to claim 1, wherein the mass ratio of the silver precursor to the stabilizer in the step (3) is 0.1% -1000%.

8. The method for preparing the titanium dioxide modified activated carbon carrying silver single atom according to claim 1, wherein the low temperature in the step (3) is-200 to 0 ℃; the reaction time is from 1 minute to 10 hours.

9. the method for preparing the titanium dioxide modified activated carbon loaded with silver monoatomic atoms according to claim 1, wherein the reducing agent in the step (3) is any one or more of hydrazine hydrate, oxalic acid, sodium borohydride, ethanol, potassium borohydride, stannous chloride, sodium thiosulfate, ferrous ammonium sulfate, sodium sulfite, and potassium sulfite.

10. The method for preparing the titanium dioxide modified activated carbon loaded with silver monoatomic atoms according to claim 1, wherein the prepared titanium dioxide modified activated carbon loaded with silver monoatomic atoms has a content of metallic silver of 0.0001-99.99wt% and has good catalytic performance and stability to formaldehyde at room temperature.

Technical Field

the invention belongs to the field of catalysts, and particularly relates to a titanium dioxide modified activated carbon supported silver monatomic catalyst and application thereof in formaldehyde oxidation.

background

the formaldehyde released by the interior decoration material is one of important indoor pollutants threatening human health, has carcinogenic effect, and has larger toxic effect on newborns, infants and old people. And is therefore extremely important for the removal of formaldehyde. Currently, activated carbon adsorption is a common method for purifying formaldehyde, but activated carbon is easy to adsorb non-polar compounds, has poor adsorption effect on polar molecules such as formaldehyde and the like, and pores of activated carbon can be blocked by impurities to seriously affect the adsorption effect. The photocatalyst is a generic name of photo-semiconductor materials with photocatalytic function represented by nano-scale titanium dioxide, and is one of the safest materials for treating indoor environmental pollution internationally. The photocatalyst can generate a photocatalytic reaction similar to photosynthesis under the irradiation of ultraviolet light to generate free hydroxyl and active oxygen with extremely strong oxidizing power, has a very strong photooxidation-reduction function, can oxidize and decompose various organic compounds and partial inorganic substances, can destroy cell membranes of bacteria and protein of solidified viruses, can kill bacteria and decompose organic pollutants, and decomposes the organic pollutants into pollution-free water and carbon dioxide, so that the photocatalyst has extremely strong functions of sterilization, deodorization, mildew prevention, pollution prevention, self cleaning and air purification.

In recent years, silver has been designed as a monatomic catalyst, and has good catalytic performance because of its own monatomic size effect and good adsorption/desorption energy. In order to ensure the use effect of the noble metal catalyst and reduce the use amount and save the cost, the silver metal catalyst particles prepared by a plurality of methods reported at present have a nanometer size, low utilization rate of silver metal atoms and poor room temperature degradation effect.

Disclosure of Invention

The invention aims to overcome the defects of the prior art and provide a titanium dioxide modified activated carbon silver-loaded monatomic preparation method which has good catalytic performance and simple preparation process.

the purpose of the invention can be realized by the following technical scheme:

The preparation method of the titanium dioxide modified activated carbon loaded silver monoatomic atom comprises the following steps:

Pretreatment of activated carbon

The active carbon is stirred in strong oxidant solution at a controlled temperature for reaction, cooled to room temperature, filtered, washed, dried in vacuum, sealed and stored;

preparation of titanium dioxide modified activated carbon carrier

Weighing pretreated active carbon, adding the active carbon into a titanium dioxide solution, and carrying out constant-temperature ultrasonic oscillation to obtain a suspension of the titanium dioxide modified active carbon carrier;

Preparation of titanium dioxide modified activated carbon loaded with silver monoatomic atom

Dissolving the titanium dioxide modified activated carbon carrier, the stabilizing agent and the silver precursor in deionized water, and slowly adding the reducing agent solution at low temperature for reaction. Washing for many times, and drying in vacuum to obtain the titanium dioxide modified activated carbon loaded silver monoatomic atom.

The strong oxidant in the step (1) is any one or combination of more of ammonium persulfate, concentrated nitric acid, potassium permanganate and concentrated sulfuric acid.

the temperature in step (1) is 40 ℃ to 190 ℃.

The mass ratio of the strong oxidant to the active carbon in the step (1) is 0.1-5000%.

In the step (2), the mass ratio of the active carbon to the titanium dioxide is 0.9-900%.

the constant temperature in the step (2) is 20 ℃ to 90 ℃.

The ultrasonic oscillation time in the step (2) is 1 minute to 300 minutes.

The stabilizer in the step (3) is any one or more of ascorbic acid, sodium citrate, aqueous vinyl acetate, acrylic ester, ethylene diamine tetraacetic acid, tributyl citrate, disodium ethylene diamine tetraacetic acid, tetrasodium ethylene diamine tetraacetic acid and sodium iron ethylene diamine tetraacetic acid.

The silver precursor in the step (3) is any one or more of silver nitrate, silver thiocyanate, silver iodide, silver carbonate, silver tetrafluoroborate, silver hexafluoroantimonate, silver phosphate, silver bis (trifluoromethanesulfonyl) imide, silver acetylacetonate, silver lactate, silver sulfadiazine, silver trifluoroacetate, silver sulfide, silver acetate, silver trifluoromethanesulfonate, silver metavanadate, silver pentafluoropropionate, silver methanesulfonate and silver p-toluenesulfonate.

The mass ratio of the silver precursor to the stabilizer in the step (3) is 0.1-1000%.

The low temperature in step (3) is-200 to 0 ℃.

The reaction time in the step (3) is 1 minute to 10 hours.

In the step (3), the reducing agent is any one or more of hydrazine hydrate, oxalic acid, sodium borohydride, ethanol, potassium borohydride, stannous chloride, sodium thiosulfate, ammonium ferrous sulfate, sodium sulfite and potassium sulfite.

The content of the prepared titanium dioxide modified activated carbon supported silver monatomic supported metallic silver is 0.0001-99.99wt%, and the prepared titanium dioxide modified activated carbon supported silver monatomic supported metallic silver has good catalytic performance and stability to formaldehyde at room temperature.

Compared with the prior art, the method has the advantages that the titanium dioxide modified active carbon is used as the carrier, the method is simple and environment-friendly, the shape characteristics of the silver monoatomic atom are uniform and regular, the removal rate of formaldehyde at room temperature is up to more than 95%, the stability of the silver monoatomic atom is good for two months, the preparation process is simple, the method is suitable for industrial scale, and the economic value is high.

Drawings

FIG. 1 is a TEM image (b) and EDS image of a titania-modified activated carbon-supported silver monatomic catalyst (a) of example 1.

FIG. 2 is a graph showing a formaldehyde adsorption rate curve of a titanium dioxide modified activated carbon supported silver monatomic catalyst;

FIG. 3 is a stability curve of a titanium dioxide modified activated carbon supported silver monatomic catalyst.

Detailed Description

The invention is described in detail below with reference to the figures and specific embodiments.