阅读说明：本技术 一种含锰氧化物负载分子筛催化剂的制备及其应用 (Preparation and application of manganese-containing oxide supported molecular sieve catalyst ) 是由 刘庆岭 郑善滨 刘彩霞 张子印 于 2019-10-22 设计创作，主要内容包括：本发明公开了一种含锰氧化物负载的分子筛催化剂的制备方法及其应用。本发明方法在将含锰氧化物负载到分子筛上的同时,利用高锰酸钾的强氧化性可以同时除去分子筛制备过程中所使用的模板剂。其中负载的锰氧化物包括MnO<Sub>2</Sub>、Mn<Sub>2</Sub>O<Sub>3</Sub>、Mn<Sub>3</Sub>O<Sub>4</Sub>以及其它含有锰元素的混合金属氧化物。本发明制备的负载型含锰催化剂,可广泛应用于环境催化领域在节约能源降低成本的同时,提高催化剂效率。具有很好的应用前景,值得大力推广应用。(The invention discloses a preparation method and application of a manganese oxide-containing loaded molecular sieve catalyst. The method can simultaneously remove the template agent used in the preparation process of the molecular sieve by utilizing the strong oxidizing property of potassium permanganate while loading the manganese-containing oxide on the molecular sieve. Wherein the supported manganese oxide comprises MnO 2 、Mn 2 O 3 、Mn 3 O 4 And other mixed metal oxides containing manganese. The supported manganese-containing catalyst prepared by the invention can be widely applied to the field of environmental catalysis, saves energy, reduces cost and improves the efficiency of the catalyst. Has good application prospect and is worth of being widely popularized and applied.)

1. The preparation method of the manganese-containing oxide supported molecular sieve catalyst is characterized by comprising the following steps:

step (1): respectively dissolving a first preset amount of potassium permanganate, a second preset amount of second metal salt and a third preset amount of molecular sieve without the template agent in an acid solution with certain concentration;

step (2): adding the molecular sieve into a potassium permanganate solution to obtain a mixed solution;

and (3): adding the obtained mixed solution into a hydrothermal reaction kettle, and preserving at a preset temperature for a first preset time period to obtain a corresponding mixture;

and (4): washing the mixture preserved at constant temperature with deionized water for a plurality of times, drying, and drying for a second preset time period;

and (5): and calcining the dried product for a third preset time period to obtain the manganese oxide-loaded molecular sieve catalyst.

2. The method of claim 1, wherein the step of preparing the supported manganese oxide molecular sieve catalyst,

the weight ratio of the adopted potassium permanganate to the molecular sieve without the template agent is 1:1 to 1: 5.

3. The method of claim 1, wherein the molecular sieve comprises a molecular sieve prepared using p123, CTAB as a template, including sba-15 and mcm-41.

4. The method of claim 1, wherein the acid used in step (1) comprises nitric acid, hydrochloric acid, and/or sulfuric acid.

5. The method of preparing a manganese-containing oxide-supported molecular sieve catalyst according to claim 1 step (1), wherein the concentration of the acid in step (1) is 0-10 mol/L.

6. The method of preparing the manganese oxide-supported molecular sieve catalyst according to claim 1, step (1), wherein the metal salt in step (1) comprises an iron salt or a copper salt.

7. The method of preparing a manganese-containing oxide-supported molecular sieve catalyst according to claim 1 step (1), wherein the molar amount of said metal salt in step (1) is 0.1 to 0.5 mol.

8. The method for preparing the manganese oxide-supported molecular sieve catalyst according to the step (1) of claim 1, wherein the predetermined temperature in the step (3) is 80-120 ℃ and the constant temperature time is 10-14 h.

9. The method for preparing the manganese oxide-supported molecular sieve catalyst according to the step (1) of claim 1, wherein the calcination temperature in the step (4) is normal temperature-550 ℃ and the calcination time is 1h-12 h.

10. Use of a molecular sieve catalyst prepared by the process of any one of claims 1 to 9 for the oxidation of acetone.

Technical Field

The invention relates to the field of catalysis, in particular to preparation and application of a supported catalyst.

Background

Pollution of volatile pollutants in the atmosphere seriously threatens the physical health of people, so that the technology for removing the volatile organic pollutants by catalysis is widely discussed and researched. The key to the catalytic removal of volatile organic pollutants is to find a catalyst with high catalytic activity.

The manganese element is a metal element with better oxidation-reduction property, and researches show that the manganese oxide has better catalytic activity on volatile organic pollutants.

The molecular sieve has large specific surface area, uniform and narrow pore size distribution, high hydrothermal stability and wide application prospect in the fields of catalysis, adsorption, separation and the like. However, molecular sieves are generally not active for volatile organic contaminants, e.g., pure silicon having an SBA-15 framework composed primarily of amorphous SiO2, and having no or low catalytic activity. The applications in the field of catalysis are therefore greatly restricted. In order to realize the potential application value of the molecular sieve, the functional design of the molecular sieve is needed, and active components are introduced into the framework, the pore walls or the pore channels of the molecular sieve through various ways to improve the catalytic activity of the molecular sieve. The conventional method is to load the active component on the surface of the molecular sieve by adopting an impregnation method. However, the supported catalyst prepared by the traditional impregnation method is easy to cause the condition that the active components are unevenly supported on the surface of the carrier, and the catalytic oxidation efficiency of the catalyst prepared by the traditional impregnation method on volatile organic pollutants such as acetone and the like is lower under the low-temperature condition.

In general, molecular sieves such as sba-15 and MCM-41 are prepared by a template method using a template such as P123 or ctab. However, before the active component is loaded on the molecular sieve, the template for preparing the molecular sieve needs to be removed by a method such as calcination. The template is removed by the roasting method, but the shrinkage of the pore channels is inevitably caused, and the template is removed by the roasting method, so that the surface properties of the molecular sieve are influenced to a certain extent, and the modification and treatment of the pore walls are not facilitated. Therefore, the invention provides a method for simultaneously removing the template agent used in the preparation process of the molecular sieve and loading the active component on the surface of the molecular sieve by utilizing the strong oxidizing property of the potassium permanganate, which is beneficial to improving the catalytic activity, improving the preparation efficiency and reducing the preparation cost.

Disclosure of Invention

Aiming at the problems in the prior art, the invention provides a preparation method of a catalyst which does not need to remove a template by roasting.

Specifically, in one aspect, the present invention provides a preparation method of a manganese-containing oxide-supported molecular sieve catalyst, which is characterized by comprising the following steps:

step (1): respectively dissolving a first preset amount of potassium permanganate, a second preset amount of second metal salt and a third preset amount of molecular sieve without the template agent in an acid solution with certain concentration;

step (2): adding the molecular sieve into a potassium permanganate solution to obtain a mixed solution;

and (3): adding the obtained mixed solution into a hydrothermal reaction kettle, and preserving at a preset temperature for a first preset time period to obtain a corresponding mixture;

and (4): washing the mixture preserved at constant temperature with deionized water for a plurality of times, drying, and drying for a second preset time period;

and (5): and calcining the dried product for a third preset time period to obtain the manganese oxide-loaded molecular sieve catalyst.

In a preferred implementation, the weight ratio of potassium permanganate employed to the molecular sieve without the template removal is from 1:1 to 1: 5.

In another preferred embodiment, the molecular sieves include molecular sieves prepared using p123, CTAB as a template, including but not limited to sba-15, mcm-41.

In another preferred embodiment, the acid used in step (1) comprises nitric acid, hydrochloric acid and/or sulfuric acid.

In another preferred embodiment, the concentration of the acid in the step (1) is 0 to 10 mol/L.

In another preferred implementation, the metal salt in the step (1) comprises iron salt and copper salt.

In another preferred embodiment, the molar amount of the metal salt in the step (1) is 0.1 to 0.5 mol.

In another preferred implementation mode, the preset temperature in the step (3) is 80-120 ℃, and the constant temperature time is 10-14 h.

In another preferred implementation mode, the roasting temperature in the step (4) is normal temperature to 550 ℃, and the roasting time is 1h to 12 h.

In another aspect, the present invention provides a use of the molecular sieve catalyst prepared by the above method, wherein the molecular sieve catalyst is used for oxidizing acetone.

As mentioned above, the invention can remove the template agent of the molecular sieve while loading the active component, thereby saving the step of roasting the template agent, being convenient and fast and saving energy.

The invention can remove the template agent and load the manganese-containing oxide as an active component on the molecular sieve, thereby obtaining good effect, and particularly obtaining good catalytic activity in the field of catalytic oxidation of volatile organic pollutants. The catalyst has high catalytic activity and stability when being used for oxidizing volatile organic pollutants in the atmosphere, and has wide market prospect. In addition, the preparation method of the manganese oxide-containing supported catalyst is simple and controllable, the preparation can be completed within 30 hours through a plurality of procedures of mixing, crystallization, drying, calcination and the like, and the preparation period is short and the repeatability is good.

The supported catalyst prepared by the invention has good application in the aspect of environmental catalytic materials, and lays a good foundation for the research and development of the supported catalyst.

Drawings

FIG. 1 is an infrared transmission plot of a catalyst of the present invention and other comparative materials, wherein a is sba15 without removal of the templating agent; b is a pattern of removing the template by a roasting method; is c is the supported manganese containing catalyst of example one. As shown in the figure, SBA-15 which is newly prepared, namely, without removing the template agent has obvious absorption peaks in the areas of 2850-3000 and 1350-1500 cm < -1 >, and can be respectively classified as C-H stretching vibration and bending vibration of the template agent P123.

As shown in figure c, the length of the groove is 2850-3000 cm and 1350-1500 cm^-1There is no obvious absorption peak to show that the template agent P123 is removed more completely in the first example, and the invention is proved that the template agent P123 can be removed at the same time when the active component is loaded on sba15 carrier.

Fig. 2 is a graph of the conversion rate of acetone oxidation versus temperature using the supported manganese-containing catalysts prepared in example one (1), example seven (2), and example eight (3) of the present invention as catalysts. Wherein the test conditions are as follows: 1000ppm acetone, 20 vol.% oxygen, N2 equilibrium, space velocity 45000mL/(g h)

Detailed Description

The present invention is further described with reference to the following examples, but the scope of the present invention is not limited by the following examples.