阅读说明：本技术 一种含氯VOCs氧化降解用Pt/Ce-USY催化剂及其制备方法 (Pt/Ce-USY catalyst for oxidative degradation of chlorine-containing VOCs and preparation method thereof ) 是由 周仁贤 李志明 石壹军 王佳露 于 2020-04-07 设计创作，主要内容包括：本发明公开了一种含氯VOCs氧化降解用Pt/Ce-USY催化剂及其制备方法,提供的含氯VOCs氧化降解用Pt/Ce-USY催化剂的制备方法,以二氯四氨合铂Ⅱ、氯化亚铈、超稳Y分子筛为原料,采用沉淀-沉积法负载CeO<Sub>2</Sub>和离子交换法负载Pt制得Pt/Ce-USY催化剂,催化剂中CeO<Sub>2</Sub>和Pt的含量分别为3～20％和0.1～0.45％。催化剂制备工艺简单、成本低,对含氯及非含氯VOCs均具有良好的低温催化氧化活性和稳定性,有良好的应用前景。(The invention discloses a Pt/Ce-USY catalyst for oxidative degradation of chlorine-containing VOCs and a preparation method thereof, and provides a preparation method of the Pt/Ce-USY catalyst for oxidative degradation of chlorine-containing VOCs, which takes platinum II tetramine dichloride, cerous chloride and an ultrastable Y molecular sieve as raw materials and adopts a precipitation-deposition method to load CeO 2 Pt is loaded by an ion exchange method to prepare a Pt/Ce-USY catalyst, and CeO in the catalyst 2 And the content of Pt is 3-20% and 0.1-0.45% respectively. The catalyst has the advantages of simple preparation process, low cost, good low-temperature catalytic oxidation activity and stability for chlorine-containing and non-chlorine-containing VOCs, and good application prospect.)

1. A Pt/Ce-USY catalyst for the oxidative degradation of chlorine-containing VOCs is characterized in that platinum II (Pt (NH) tetraammine chloride is used₃)₄Cl₂·H₂O), cerous chloride (CeCl)₃·7H₂O), ammonium ultrastable Y molecular sieve (NH)₄-USY) as main raw material, and carrying CeO by precipitation-deposition method₂And loading Pt by an ion exchange method to prepare a Pt/Ce-USY catalyst, wherein CeO in the catalyst₂The content is 3-20%, and the content of Pt is 0.1-0.45%.

2. A preparation method of a Pt/Ce-USY catalyst for oxidative degradation of chlorine-containing VOCs comprises the following specific preparation steps:

1) as described in CeO₂CeCl with a content of 0.012-0.12 mol/L₃Adding a set amount of powdered NH to the aqueous solution₄-USY, adding ammonia (NH) with concentration of 1.0 mol/L dropwise under vigorous stirring after stirring uniformly₃·H₂O), dropwise adding the mixture until the pH value of the mixed solution reaches 9-11, standing at room temperature for aging for 12 hours, then filtering, washing with deionized water for multiple times until the filtrate is neutral, drying at 60 ℃ for 12 hours, and roasting at 550 ℃ for 2 hours to obtain Ce-USY;

2) pt (NH) at a set concentration according to the Pt content₃)₄Cl₂Dissolving in waterAdding a certain amount of powder Ce-USY into the solution, refluxing at 100 deg.C for 3 hr, cooling to room temperature, adding excessive formaldehyde solution (CH)₂O) is placed for 4 hours, then filtered and washed by deionized water for a plurality of times until no Cl is detected in the filtrate^-Drying at 60 ℃ for 12 hours, and roasting at 500 ℃ for 2 hours to prepare the Pt/Ce-USY catalyst.

3. The method for preparing Pt/Ce-USY catalyst for oxidative degradation of VOCs containing chlorine as claimed in claim 2, wherein said CeO₂The optimum content of the Pt is 6-12%, and the optimum content of the Pt is 0.3-0.45%.

4. The method for preparing the Pt/Ce-USY catalyst for oxidative degradation of VOCs containing chlorine according to claim 3, wherein in the step 2), CH is added₂The molar ratio of O to Pt is greater than 5.0.

Technical Field

The invention relates to a preparation method of a catalyst for low-temperature oxidative degradation of chlorine-containing VOCs, in particular to a Pt/Ce-USY catalyst for oxidative degradation of chlorine-containing VOCs and a preparation method thereof.

Background

chlorine-Containing Volatile Organic Compounds (CVOCs) are compounds which are extremely harmful to the environment and human health, and common compounds include Dichloromethane (DCM), trichloromethane (CF), Dichloroethane (DCE), Trichloroethylene (TCE), Carbon Tetrachloride (CT), chlorobenzene (PhCl), and the like, and because of their good chemical stability, they are generally widely used as organic solvents and semi-finished products in chemical production processes. The catalytic combustion technology is one of important and effective means for purifying CVOCs pollutants, and the development of a low-cost and high-performance catalyst is the key for realizing the application of the technology. Solid acid (such as molecular sieve) is compounded with cerium-based oxide, so that the catalyst has good acidity and oxidizability, and can promote deep oxidation of intermediate products while maintaining the environment beneficial to adsorption and bond breaking of CVOCs, thereby attracting much attention in recent years. However, the chlorine-containing organic waste gas discharged from the actual industry often contains non-chlorine-containing hydrocarbon organic compounds (such as benzene, alkane, etc.), but the non-noble metal catalyst has low oxidation activity on such VOCs, and in addition, due to competitive adsorption, the catalyst is not favorable for adsorbing and activating CVOCs, and is easy to be deactivated by carbon deposition. Therefore, the development of the high-efficiency, broad-spectrum and stable chlorine-containing organic waste gas combustion catalyst has important significance for the wide application of the catalytic combustion technology.

Disclosure of Invention

The invention aims to provide a high-efficiency broad-spectrum chlorine-containing organic waste gas combustion catalyst, in particular to a Pt/Ce-USY catalyst for the oxidative degradation of chlorine-containing VOCs and a preparation method thereof, and the invention is realized by the following technical scheme:

the invention discloses a Pt/Ce-USY catalyst for oxidative degradation of chlorine-containing VOCs (volatile organic compounds), which is prepared by taking platinum (II) (Pt (NH) tetraammine chloride₃)₄Cl₂·H₂O), cerous chloride (CeCl)₃·7H₂O), ammonium ultrastable Y molecular sieve (NH)₄-USY) as main raw material, and carrying CeO by precipitation-deposition method₂Pt is loaded by an ion exchange method to prepare a Pt/Ce-USY catalyst, and CeO in the catalyst₂The content is 3-20%, and the content of Pt is 0.1-0.45%.

The invention also discloses a preparation method of the Pt/Ce-USY catalyst for oxidative degradation of the chlorine-containing VOCs, which comprises the following specific preparation steps:

1) as described in CeO₂CeCl with a content of 0.012-0.12 mol/L₃Adding a set amount of powdered NH to the aqueous solution₄-USY, adding ammonia (NH) with concentration of 1.0 mol/L dropwise under vigorous stirring after stirring uniformly₃·H₂O), dropwise adding the mixture until the pH value of the mixed solution reaches 9-11, standing at room temperature for aging for 12 hours, then filtering, washing with deionized water for multiple times until the filtrate is neutral, drying at 60 ℃ for 12 hours, and roasting at 550 ℃ for 2 hours to obtain Ce-USY;

2) pt (NH) at a set concentration according to the Pt content₃)₄Cl₂Adding a certain amount of powder Ce-USY into the aqueous solution, refluxing at 100 deg.C for 3 hr, cooling to room temperature, adding excessive formaldehyde solution (CH)₂O) is placed for 4 hours, then filtered and washed by deionized water for a plurality of times until no Cl is detected in the filtrate^-Drying at 60 ℃ for 12 hours, and roasting at 500 ℃ for 2 hours to prepare the Pt/Ce-USY catalyst.

As a further improvement, the CeO of the present invention₂The optimum content of the Pt is 6-12%, and the optimum content of the Pt is 0.3-0.45%.

As a further improvement, in the step 2) of the invention, CH₂The molar ratio of O to Pt is greater than 5.0.

The preparation method of the Pt/Ce-USY catalyst provided by the invention has the advantages that: the Pt/Ce-USY catalyst is prepared by adopting cheap cerous chloride, an industrially produced USY molecular sieve and a small amount of Pt (platinum II dichlorotetramine) as raw materials and adopting a precipitation-deposition combined ion exchange method, has simple preparation process, low cost and high low-temperature oxidation activity, and is a high-efficiency broad-spectrum chlorine-containing organic waste gas combustion catalyst. The catalyst has good low-temperature catalytic degradation activity and stability for chlorine-containing VOCs such as dichloroethane and the like and non-chlorine-containing VOCs such as benzene and the like, and has important significance for wide application of catalytic combustion technology.

The specific implementation mode is as follows:

the invention discloses a Pt/Ce-USY catalyst for oxidative degradation of chlorine-containing VOCs and a preparation method thereof, wherein the catalyst is prepared by taking platinum-IV-diammine-dichloride II (Pt (NH)₃)₄Cl₂·H₂O), cerous chloride (CeCl)₃·7H₂O), ammonium ultrastable Y molecular sieve (NH)₄-USY) as main raw material and adopting precipitation-deposition method to prepare negativeCarried CeO₂Pt is loaded by an ion exchange method to prepare a Pt/Ce-USY catalyst, and CeO in the catalyst₂The content of the Pt is 3-20%, the content of the Pt is 0.1-0.45%, and the specific preparation steps are as follows:

1) as described in CeO₂CeCl with a content of 0.012-0.12 mol/L₃Adding a set amount of powdered NH to the aqueous solution₄-USY, adding ammonia (NH) with concentration of 1.0 mol/L dropwise under vigorous stirring after stirring uniformly₃·H₂O), dropwise adding the mixture until the pH value of the mixed solution reaches 9-11, standing at room temperature for aging for 12 hours, then filtering, washing with deionized water for multiple times until the filtrate is neutral, drying at 60 ℃ for 12 hours, and roasting at 550 ℃ for 2 hours to obtain Ce-USY;

2) pt (NH) at a set concentration according to the Pt content₃)₄Cl₂Adding a certain amount of powder Ce-USY into the aqueous solution, refluxing at 100 deg.C for 3 hr, cooling to room temperature, adding excessive formaldehyde solution (CH)₂O) is placed for 4 hours, then filtered and washed by deionized water for a plurality of times until no Cl is detected in the filtrate^-Drying at 60 ℃ for 12 hours, and roasting at 500 ℃ for 2 hours to prepare the Pt/Ce-USY catalyst.

CeO₂The optimal content of (2) is 6-12%, the optimal content of Pt is 0.3-0.45%, and in the step 2), CH₂The molar ratio of O to Pt is greater than 5.0.

The technical solution of the present invention is further illustrated by the following specific examples: