阅读说明：本技术 稀土修饰的吸附富集-催化氧化双功能催化剂及其制备方法和应用 (Rare earth modified adsorption enrichment-catalytic oxidation bifunctional catalyst and preparation method and application thereof ) 是由 崔大祥 蔡婷 袁静 赵昆峰 金彩虹 于 2019-11-09 设计创作，主要内容包括：本发明涉及一种稀土修饰的吸附富集-催化氧化双功能催化剂及其制备方法和应用,该催化剂主要包括载体和活性组分,活性组分负载在载体上,所述载体为稀土元素(Ce,Zr,La)修饰的活性炭；所述活性组分为氧化锰。其中,以元素摩尔量计,稀土元素的负载量为0.5%-1%,锰的负载量为2%-5%。该制备方法本发明制得的催化剂催化效率高,制备方法简单,生产和应用成本低。(The invention relates to a rare earth modified adsorption enrichment-catalytic oxidation bifunctional catalyst and a preparation method and application thereof, wherein the catalyst mainly comprises a carrier and an active component, the active component is loaded on the carrier, and the carrier is rare earth element (Ce, Zr, La) modified active carbon; the active component is manganese oxide. Wherein, the loading capacity of the rare earth element is 0.5 to 1 percent and the loading capacity of the manganese is 2 to 5 percent based on the element mol. The catalyst prepared by the preparation method has high catalytic efficiency, simple preparation method and low production and application cost.)

1. The rare earth modified adsorption enrichment-catalytic oxidation dual-function catalyst is characterized by comprising a carrier and an active component, wherein the carrier is activated carbon modified by rare earth elements Ce, Zr and/or La, the active component is manganese oxide, and the loading capacity of the rare earth elements is 0.5% -1% and the loading capacity of the manganese is 2% -5% in terms of element molar weight.

2. The preparation method of the rare earth modified adsorption enrichment-catalytic oxidation dual-function catalyst according to claim 1, which is characterized by comprising the steps of preparing a rare earth element impregnation solution, impregnating activated carbon into the prepared impregnation solution to prepare a rare earth element modified carrier, adding a potassium permanganate solution into the rare earth element impregnated activated carbon carrier, synthesizing an activated carbon supported manganese oxide catalyst in situ by using the redox reaction of the activated carbon and potassium permanganate, and further modifying the surface of the prepared catalyst by using ammonia water, wherein the preparation method comprises the following steps:

(1) dissolving cerium nitrate, zirconium nitrate or lanthanum nitrate in water to prepare a rare earth element precursor solution, wherein the molar concentration of the rare earth element is 0.01 mol/L;

(2) taking the rare earth element precursor solution prepared in the step (1), soaking activated carbon in the obtained rare earth element precursor solution, and standing overnight;

(3) preparing 0.1mol/L potassium permanganate solution, adding the potassium permanganate solution into the carriers impregnated with different rare earth elements in the step (2) respectively, and stirring for 4-6h to obtain precipitates;

(4) filtering and washing the obtained precipitate, and drying at 40-60 ℃ to obtain an active carbon catalyst loaded with an active component manganese;

(5) and (4) measuring the water absorption rate of the manganese oxide activated carbon catalyst obtained in the step (4), soaking 10% diluted ammonia water in an equal volume, and drying at 40-60 ℃ to obtain the ammonia modified activated carbon supported manganese oxide catalyst.

3. A method for preparing the rare earth modified adsorptive enrichment-catalytic oxidation dual-function catalyst according to claim 2, wherein the method comprises the following steps:

(1) weighing 0.87g of cerous nitrate hexahydrate to be dissolved in 200ml of water to prepare a cerous nitrate solution with the concentration of 0.01 mol/L;

(2) weighing 20g of active carbon, soaking the active carbon in 71ml of cerium nitrate solution, and standing overnight;

(3) preparing 0.1mol/L potassium permanganate solution, adding 73ml of the potassium permanganate solution into the activated carbon impregnated with different rare earth elements Ce, and stirring for 4 hours to obtain a precipitate;

(4) filtering and washing the obtained precipitate, and drying at 60 ℃ to obtain an active carbon catalyst loaded with an active component manganese;

(5) and (3) measuring the water absorption rate of the manganese oxide activated carbon catalyst obtained in the step (4) to be 1.2g of water/g of activated carbon, soaking 10% diluted ammonia water in an equal volume, and drying at 60 ℃ to obtain the ammonia modified activated carbon loaded manganese oxide catalyst, which is recorded as 2Mn-Ac-0.5 Ce.

4. A method for preparing the rare earth modified adsorptive enrichment-catalytic oxidation dual-function catalyst according to claim 2, wherein the method comprises the following steps:

(1) weighing 0.87g of lanthanum nitrate hexahydrate, dissolving in 200ml of water, and preparing lanthanum nitrate with the concentration of 0.01 mol/L;

(2) weighing 20g of activated carbon, soaking the activated carbon in 142ml of lanthanum nitrate solution, and standing overnight;

(3) preparing 0.1mol/L potassium permanganate solution, adding 73ml of the potassium permanganate solution into the activated carbon impregnated with the rare earth elements in the step (2), and stirring for 4 to obtain a precipitate;

(4) filtering and washing the obtained precipitate, and drying at 40 ℃ to obtain an active carbon catalyst loaded with an active component manganese;

(5) and (3) measuring the water absorption rate of the manganese oxide activated carbon catalyst obtained in the step (4) to be 1.2g of water/g of activated carbon, soaking 10% diluted ammonia water in an equal volume, and drying at 40 ℃ to obtain the ammonia modified activated carbon loaded manganese oxide catalyst, which is recorded as 2Mn-Ac-1 La.

5. A method for preparing the rare earth modified adsorptive enrichment-catalytic oxidation dual-function catalyst according to claim 2, wherein the method comprises the following steps:

(1) weighing 0.87g of lanthanum nitrate hexahydrate, dissolving in 200ml of water, and preparing a lanthanum nitrate solution with the concentration of 0.01 mol/L;

(2) weighing 20g of activated carbon, soaking the activated carbon in 71ml of lanthanum nitrate solution, and standing overnight;

(3) preparing 0.1mol/L potassium permanganate solution, adding 182ml of 0.1mol/L potassium permanganate solution into the carrier soaked with the rare earth elements in the step (2), and stirring for 4 hours to obtain a precipitate;

(4) filtering and washing the obtained precipitate, and drying at 60 ℃ to obtain an active carbon catalyst loaded with an active component manganese;

(5) and (3) measuring the water absorption rate of the manganese oxide activated carbon catalyst obtained in the step (4) to be 1.2g of water/g of activated carbon, soaking 10% diluted ammonia water in an equal volume, and drying at 60 ℃ to obtain the ammonia modified activated carbon loaded manganese oxide catalyst which is recorded as 5Mn-Ac-0.5 La.

6. A method for preparing the rare earth modified adsorptive enrichment-catalytic oxidation dual-function catalyst according to claim 2, wherein the method comprises the following steps:

(1) weighing 0.86g of zirconium nitrate hexahydrate, dissolving in 200ml of water, and preparing a zirconium nitrate solution with the concentration of 0.01 mol/L;

(2) weighing 20g of active carbon, soaking the active carbon in 71ml of zirconium nitrate solution, and standing overnight;

(3) preparing 0.1mol/L potassium permanganate solution, adding 73ml of 0.1mol/L potassium permanganate solution into the carrier soaked with different rare earth elements in the step (2), and stirring for 4 hours to obtain a precipitate;

(4) filtering and washing the obtained precipitate, and drying at 40 ℃ to obtain an active carbon catalyst loaded with an active component manganese;

(5) and (3) measuring the water absorption rate of the manganese oxide activated carbon catalyst obtained in the step (4) to be 1.2g of water/g of activated carbon, soaking 10% diluted ammonia water in an equal volume, and drying at 40 ℃ to obtain the ammonia modified activated carbon loaded manganese oxide catalyst, which is recorded as 2Mn-Ac-0.5 Zr.

7. A method for preparing the rare earth modified adsorptive enrichment-catalytic oxidation dual-function catalyst according to claim 2, wherein the method comprises the following steps:

(1) weighing 0.86g of zirconium nitrate hexahydrate, dissolving in 200ml of water, and preparing a zirconium nitrate solution with the concentration of 0.01 mol/L;

(2) weighing 20g of activated carbon, soaking the activated carbon in 142ml of zirconium nitrate solution, and standing overnight;

(3) preparing 0.1mol/L potassium permanganate solution, adding 182ml of 0.1mol/L potassium permanganate solution into the carriers soaked with different rare earth elements in the step (2), and stirring for 4 hours to obtain precipitates;

(4) filtering and washing the obtained precipitate, and drying at 40 ℃ to obtain an active carbon catalyst loaded with an active component manganese;

(5) and (3) measuring the water absorption rate of the manganese oxide activated carbon catalyst obtained in the step (4) to be 1.2g of water/g of activated carbon, soaking 10% diluted ammonia water in an equal volume, and drying at 40 ℃ to obtain the ammonia modified activated carbon loaded manganese oxide catalyst, which is recorded as 5Mn-Ac-1 Zr.

8. Use of the rare earth modified adsorptive enrichment-catalytic oxidation dual-function catalyst according to claim 1 for formaldehyde purification with a total gas flow of 500ml/min, a reaction pressure of 1atm at normal pressure, an initial formaldehyde concentration of 2ppm (V/V) and a sample amount of 2 g.

Technical Field

The invention belongs to the technical field of catalytic environment protection, and particularly relates to a rare earth modified adsorption enrichment-catalytic oxidation bifunctional catalyst, and a preparation method and application thereof.

Background

Along with the increasingly prominent environmental problems, indoor environmental problems have led to the attention of more people. Formaldehyde is one of the most common and most toxic pollutants in interior decoration. Formaldehyde has been identified by the world health organization as a carcinogenic and teratogenic substance, is a well-recognized source of allergy, is also one of the potential strong mutagens, causes various diseases, and has strong carcinogenic and carcinogenic effects. According to the survey of the international organization, nearly 300 million people worldwide die directly or indirectly from formaldehyde pollution caused by decoration every year. Therefore, the problem of formaldehyde pollution in indoor air needs to be solved.

Since formaldehyde has high toxicity and dynamically changes in the air, the detection difficulty is huge, and the research work for removing low-concentration formaldehyde is difficult. At present, the formaldehyde is removed mainly by adopting an adsorption method, and although a single adsorption method has relatively good formaldehyde removal effect, the single adsorption method is easy to inactivate due to adsorption saturation and easily causes secondary pollution. The catalytic oxidation method can convert formaldehyde into carbon dioxide, but the effect of removing low-concentration pollution is not good, and the currently researched catalyst is mainly a noble metal catalyst, so that the cost of the catalyst is high, and the application effect is poor. Aiming at the problems of the existing formaldehyde purification material, the invention provides a purification material integrating adsorption enrichment and catalytic oxidation, active components grow in situ, the purification effect of the material on formaldehyde is greatly improved, and the catalyst is low in cost.

Disclosure of Invention

Aiming at the problems that formaldehyde treated by a single adsorption technology is easily saturated and easily causes secondary pollution, and formaldehyde with extremely low concentration is difficult to treat by single catalytic oxidation, the invention aims to provide a rare earth modified adsorption enrichment-catalytic oxidation dual-function catalyst.

Yet another object of the present invention is to: provides a preparation method of the rare earth modified adsorption enrichment-catalytic oxidation dual-function catalyst product.

Yet another object of the present invention is to: provides an application of the product.

The purpose of the invention is realized by the following scheme: the rare earth modified adsorption enrichment-catalytic oxidation dual-function catalyst comprises a carrier and an active component, wherein the carrier is activated carbon modified by rare earth elements Ce, Zr and/or La, and the active component is manganese oxide, wherein the loading capacity of the rare earth elements is 0.5% -1% and the loading capacity of the manganese is 2% -5% in terms of element molar weight.

The invention also provides a preparation method of the rare earth modified adsorption enrichment-catalytic oxidation dual-function catalyst, which comprises the steps of preparing a rare earth element impregnation liquid, impregnating activated carbon into the prepared impregnation liquid to prepare a rare earth element modified carrier, adding a potassium permanganate solution into the rare earth element impregnated activated carbon carrier, synthesizing an activated carbon-supported manganese oxide catalyst in situ by using the redox reaction of the activated carbon and potassium permanganate, and further modifying the surface of the prepared catalyst by using ammonia water, and comprises the following steps:

(1) dissolving cerium nitrate, zirconium nitrate or lanthanum nitrate in water with a certain volume to prepare a rare earth element precursor solution, wherein the molar concentration of the rare earth element is 0.01 mol/L;

(2) taking a certain volume of the rare earth element precursor solution prepared in the step (1), soaking a certain mass of activated carbon in the obtained rare earth element precursor solution, and standing overnight;

(3) preparing a potassium permanganate solution with a certain volume of 0.1mol/L, adding the potassium permanganate solution with a certain volume into the carriers impregnated with different rare earth elements in the step 2 respectively, and stirring for 4-6h to obtain a precipitate;

(4) filtering and washing the obtained precipitate, and drying at 40-60 ℃ to obtain an active carbon catalyst loaded with an active component manganese;

(5) and (4) measuring the water absorption rate of the manganese oxide activated carbon catalyst obtained in the step (4), soaking 10% diluted ammonia water in an equal volume, and drying at 40-60 ℃ to obtain the ammonia modified activated carbon supported manganese oxide catalyst.

The invention also provides application of the rare earth modified adsorption enrichment-catalytic oxidation dual-function catalyst, in order to be used for formaldehyde purification, the total flow of gas is 500ml/min, the reaction pressure is normal pressure and 1atm, the initial concentration of formaldehyde is 2ppm (V/V), and the sample dosage is 2 g.

The formaldehyde purification catalyst prepared by the method has a good effect on removing formaldehyde in air, the conversion rate can reach 80% -100% at room temperature, and the preparation method disclosed by the invention is simple, low in cost, and high in practical value due to one-step forming of the catalyst.

Compared with the existing formaldehyde purification material and the preparation method thereof, the formaldehyde purification material has the following characteristics: the purification efficiency of low-concentration formaldehyde pollutants is greatly improved by utilizing the synergistic action of adsorption and catalysis, and the removal efficiency of formaldehyde at normal temperature can reach 100%; the catalyst utilizes the in-situ oxidation-reduction reaction of the activated carbon and the potassium permanganate in the surface and the pore channel structure, and simultaneously generates active components in situ on the surface and the pore channel structure, thereby greatly improving the dispersion degree of the active components and further improving the catalytic activity. The catalyst prepared by the preparation method has high catalytic efficiency, simple preparation method and low production and application cost.

DETAILED DESCRIPTION OF EMBODIMENT (S) OF INVENTION