CN117619379A - A kind of catalyst RuO2-SnTiOx and its preparation method and application - Google Patents

Abstract

The invention provides a catalyst RuO ₂ ‑SnTiO _x And a preparation method and application thereof, wherein the preparation method comprises the steps of S1, preparing a carrier SnTiO _x The method comprises the steps of carrying out a first treatment on the surface of the Step S2, preparing a catalyst RuO ₂ ‑SnTiO _x Adding ruthenium source into water, and adding carrier SnTiO _x And surfactant, stirring for 1-2h, filtering, washing, and drying to obtain RuO ₂ ‑SnTiO _x A precursor; ruO is to be made into ₂ ‑SnTiO _x Calcining the precursor at 450-550 deg.c for 4-6 hr to obtain RuO catalyst ₂ ‑SnTiO _x . The catalyst RuO ₂ ‑SnTiO _x The preparation method is used for preparing the product. The application is to make the catalyst RuO ₂ ‑SnTiO _x The method is applied to catalytic conversion of chlorinated volatile organic compounds. Prepared by the inventionThe catalyst has low cost and stable catalytic performance, and can effectively catalyze the reaction of chlorine-containing components and purify CVOCs.

Description

A kind of catalyst RuO2-SnTiOx and its preparation method and application

Technical field

The invention relates to the technical field of exhaust gas pollution control, and specifically relates to a catalyst RuO ₂ -SnTiO _x and its preparation method and application.

Background technique

Volatile organic compounds (abbreviated as VOCs) mainly originate from processes such as coal chemical industry, petrochemical industry, fuel coating manufacturing, and solvent manufacturing and use. They are important precursors for the formation of ozone and haze, and can harm human health. How to reduce VOCs emissions is a major challenge. Among various VOCs pollutants, chlorinated volatile organic compounds (CVOCs) are a major type, which are mainly derived from intermediates and final products of certain industrial processes. CVOCs can contaminate water, air and soil during the production, use and post-use disposal of containers, and can enter the human body through inhalation or skin contact, posing potential health risks. Since CVOCs are volatile, non-degradable and highly toxic, the development of efficient, economical and environmentally friendly CVOCs degradation technology is one of the current focuses of the environmental protection field.

Among exhaust gas pollution control technologies, catalytic conversion of CVOCs is considered an effective method with low energy consumption and the ability to completely eliminate CVOCs. At present, CVOCs catalysts mainly include the following types: non-noble metal-based (such as Mn, Ce, Fe and Cu) and precious metal-based (such as Ru, Pt and Pd). Transition metal oxide catalysts have received widespread attention due to their relatively cheap properties and good thermal stability. For example, MnO _x , CeO ₂ , FeO _x , Cr ₂ O ₃ and V ₂ O ₅ have high degradation activity for CVOCs, but Active sites are lost due to the formation of chlorinated metal oxides until they gradually lose activity.

Although noble metals (such as Pt and Pd) have high catalytic activity, they are often not suitable for industrial production due to their high price. Although Ru is a precious metal, it is cheaper than Pt and Pd. Therefore, Ru is a promising alternative that can reduce the cost of industrial applications. Furthermore, the supported Ru catalyst shows high dechlorination efficiency during the catalytic conversion of CVOCs, and the supported Ru is not easily combined with chlorine, ensuring stable catalyst activity.

Therefore, the development of a low-cost and stable catalytic performance catalyst RuO ₂ -SnTiO _x and its preparation method and application has great development needs and significant application prospects.

Contents of the invention

The purpose of the present invention is to provide a catalyst RuO _{2 -SnTiO} Loss and rapid deactivation of the catalyst. The specific technical solutions are as follows:

In a first aspect, the present invention provides a preparation method of catalyst RuO ₂ -SnTiO _x , including:

Step S1, prepare the carrier SnTiO _x ;

Add the tin source and the titanium source into the water and stir for 1-2 hours to obtain a first mixed solution; wherein, the molar ratio of the tin element in the tin source to the titanium element in the titanium source is 1-3:2-4;

Add the precipitant to the water and stir until dissolved, then add the first mixed solution, stir for 1-2 hours, filter, wash, and dry to obtain the SnTiO _x precursor;

The SnTiO _x precursor is calcined at 450 to 550°C for 4 to 6 hours to obtain the carrier SnTiO _x ; where the value of x is 4-6;

Step S2, prepare catalyst RuO ₂ -SnTiO _x

Add the ruthenium source to _water , add the carrier SnTiO _x and surfactant, stir for 1-2 hours, filter, wash, and dry to obtain the RuO _{2 -SnTiO} The ratio is 0.5-3:100:16.5;

The RuO ₂ -SnTiO _x precursor is calcined at 450 to 550°C for 4 to 6 hours to obtain the catalyst RuO ₂ -SnTiO _x .

Optionally, the loading amount of RuO ₂ in the catalyst RuO ₂ -SnTiO _x is 0.5-3wt%.

Optionally, the tin source includes at least one of stannous chloride and tin acetate; the titanium source includes at least one of tetrabutyl titanate and metatitanic acid; the ruthenium source includes ruthenium acetate and At least one kind of ruthenium chloride.

Optionally, the precipitating agent includes at least one of ammonium bicarbonate, ammonia water and sodium hydroxide.

Optionally, the surfactant includes at least one of cyclodextrin, polyvinylpyrrolidone and fullerene.

Optionally, the drying condition parameters used in steps S1-S2 are drying temperature 80-100°C and drying time 8-12h.

Optionally, in steps S1-S2, the calcination condition parameter is used to raise the temperature at a heating rate of 3 to 5°C/min.

In a second aspect, the present invention provides a catalyst RuO ₂ -SnTiO _x , which is prepared according to the preparation method of the catalyst RuO ₂ -SnTiO _x .

In a third aspect, the present invention provides _an application of _a catalyst RuO ₂ -SnTiO _x , which is used to catalytically convert chlorinated volatile organic compounds.

Optionally, when the catalyst RuO ₂ -SnTiO _x catalytically converts chlorinated volatile organic compounds, the reaction temperature used is 330 to 550°C.

Applying the technical solution of the present invention has at least the following beneficial effects:

(1) A method for preparing a catalyst RuO ₂ -SnTiO _x provided by the invention uses a carrier SnTiO _x to load RuO ₂ so that the active sites of the catalyst RuO ₂ -SnTiO _x have an anti-chlorine effect and will not cause the loss of active sites. This ensures that the catalyst RuO ₂ -SnTiO _x has stable activity when catalytically converting CVOCs.

^{Specifically ,} _{in the} carrier _SnTiO The Lewis acidity and thermal stability of the catalyst are enhanced; while Ru grows on the top of the _SnTiO Sn structure; among them, the Ru-O-Ti structure provides strong alkaline surface lattice oxygen, and the Ru-O-Sn structure increases the catalyst surface oxygen, which enhances the oxidation rate of RuO ₂ and improves the chlorine resistance of the catalyst;

At the same time, the addition of surfactants during the preparation process also enhances the high dispersion between the active component RuO ₂ and the carrier, reduces the possibility of catalyst deactivation due to sintering of the active component, and thereby maintains the activity of the catalyst.

The preparation method of the invention has simple process, low cost and is easy to promote industrial production. It can be well used in catalytic oxidation reactions of CVOCs.

(2) In the method of preparing the catalyst RuO ₂ -SnTiO _x in the present invention, in order to improve the catalytic activity, the loading amount of RuO ₂ needs to be controlled to 0.5-3wt%. Specifically, if the RuO ₂ loading is too low, the sparse distribution of Ru particles will not be able to dissociate the chlorine-containing components in CVOCs; if the RuO ₂ loading is too high, the Ru particles will easily aggregate and the active sites will be covered, thus Limit the conversion rate.

(3) The catalyst RuO ₂ -SnTiO _x prepared by the invention has low cost and stable catalytic performance.

(4) The present invention uses the catalyst RuO ₂ -SnTiO _x to catalytically convert CVOCs, which can effectively catalyze the reaction of chlorine-containing components and purify CVOCs.

In addition to the objects, features and advantages described above, the present invention has other objects, features and advantages. The present invention will be described in further detail below with reference to the drawings.

Description of drawings

The drawings forming a part of this application are used to provide a further understanding of the present invention. The illustrative embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the attached picture:

Figure 1 is a conversion rate diagram of the catalytic conversion of CVOCs at different temperatures by the catalyst RuO ₂ -SnTiO _x prepared in Examples 1-4 of the present invention;

Figure 2 is a conversion rate relationship diagram of the catalyst RuO 2 -SnTiO _x prepared in Example 3 of the present invention when the catalyst RuO ₂ -SnTiO x is operated for 100 hours of catalytic conversion of CVOCs;

Figure 3 is the XRD pattern of the catalyst RuO ₂ -SnTiO _x prepared in Examples 1-4 of the present invention and the reference material;

Figure 4 is a conversion rate diagram of the catalysts prepared in Comparative Examples 1-4 of the present invention catalytically converting CVOCs at different temperatures;

Among them, the main chlorine-containing substance of the CVOCs used in Figures 1, 2 and 4 is chlorobenzene, its concentration is 500ppm, and the space velocity is 150000ml·g ^-1 ·h ^-1 .

Detailed ways

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only some of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art fall within the scope of protection of the present invention.

A preparation method of catalyst RuO ₂ -SnTiO _x , including:

Step S1: Prepare carrier SnTiO _x .

Add the tin source (specifically stannous chloride SnCl ₂ ) and titanium source (specifically tetrabutyl titanate Ti(OC ₄ H ₉ ) ₄ ) into deionized water and stir for 0.5h at room temperature and normal pressure to obtain the first Mixed solution; wherein, the molar ratio of the tin element in the tin source to the titanium element in the titanium source is 2:3;

Add the precipitant (specifically ammonium bicarbonate) to deionized water and stir at room temperature until dissolved, then gradually add the first mixed solution dropwise, and stir for 1-2 hours until the yellow precipitation is complete; then filter, wash, and dry to obtain SnTiO _x precursor;

The SnTiO _x precursor is calcined in a muffle furnace at 550°C for 4 hours under an air atmosphere to obtain the carrier SnTiO _x ; where, the value of x is 4-6, specifically 6;

Step S2, prepare catalyst RuO ₂ -SnTiO _x

Add the ruthenium source (specifically ruthenium chloride) to deionized water, and add the carrier _{SnTiO 2} -SnTiO _x precursor; wherein the mass ratio of the ruthenium source, carrier SnTiO _x and surfactant is 0.5-3:100:16.5;

The RuO ₂ -SnTiO _x precursor was calcined in a muffle furnace at 550°C for 4 hours under an air atmosphere, and then cooled to room temperature. The obtained solid catalyst was ground into powder to obtain the catalyst RuO ₂ -SnTiO _x .

The drying condition parameters used in steps S1-S2 are drying temperature 80°C and drying time 12h.

In steps S1-S2, the calcination condition parameter is used to raise the temperature at a heating rate of 5°C/min.

According to the preparation method of _the catalyst _{RuO 2 -SnTiO} -The specific loading amount in SnTiO _x , the specific dosage and loading amount are shown in Table 1.

Table 1

The specific amounts of tin source and titanium source in Examples 1-4 and the specific loading of RuO ₂ in the catalyst RuO ₂ -SnTiO _x

When the catalyst RuO ₂ -SnTiO _x prepared in Example 1-4 catalytically converts CVOCs, the reaction temperature used is 330 to 550°C. The catalytic results are shown in Figure 1.

It can be seen from Table 1 and Figure 1 that the catalyst RuO ₂ -SnTiO _x prepared in Examples 1-4 of the present invention all showed good catalytic performance. Among them, the catalyst RuO ₂ -SnTiO _x prepared in Example 3 showed good catalytic performance. Best catalytic performance.

It can be seen from Figure 2 that the catalyst RuO ₂ -SnTiO _x prepared in Example 3 shows stable catalytic activity even if it is used continuously for 100 hours.

Referring to Figure 3, the XRD patterns of the catalyst RuO ₂ -SnTiO _x prepared in Example 1-4 and the reference substance were completed under the same experimental conditions. It can be seen that the catalyst RuO ₂ -SnTiO _x prepared in Example 1-4 is the same as The diffraction peaks of SnO ₂ and TiO ₂ are significantly shifted, showing the diffraction peaks of SnTi rutile.

On the basis of Examples 1-4, the present invention also makes the following comparative examples:

Comparative example 1:

Different from Example 3, the amount of ruthenium source added is reduced. Specifically, the mass ratio of the ruthenium source, carrier SnTiOx and surfactant is controlled to 0.3:100:16.5, so that the RuO ₂ in the catalyst RuO ₂ -SnTiO _x The loading capacity is 0.3wt%.

Comparative example 2:

Different from Example 3, the amount of ruthenium source added is increased. Specifically, the mass ratio of the ruthenium source, carrier SnTiO _x and surfactant is controlled to 3.2:100:16.5, so that the RuO ₂ in the catalyst RuO ₂ -SnTiO _x The loading capacity is 3.2wt%.

Comparative example 3:

The difference from Example 3 is that the carrier used is TiO ₂ .

Comparative example 4:

The difference from Example 3 is that the carrier used is SnO ₂ .

Referring to Figure 4, compared to Example 3, in Comparative Example 1, too low a RuO ₂ loading was used, and the effect on the dissociation of chlorine-containing components in CVOCs was significantly reduced; compared to Example 3, too high a RuO loading was used ₂ loading capacity cannot significantly improve the catalytic effect on CVOCs; compared to Example 3, using a single carrier TiO ₂ or carrier SnO ₂ , in order to achieve the catalytic conversion rate of CVOCs in Example 3, the catalytic reaction needs to be significantly increased. temperature, increasing energy consumption.

The present invention compares the T90 data of the catalyst RuO ₂ -SnTiO _x prepared in Example 3 and the commercially available Pd catalyst, Pt catalyst and Rh catalyst using TiO ₂ as a carrier under the same catalytic conversion test conditions for CVOCs (specifically chlorobenzene). See Table 2 for test results. Among them, the test conditions for catalytic conversion of CVOCs are specifically when the catalyst powder loading is 1g, the evaluation conditions are chlorobenzene concentration of 500ppm, and space velocity of 150000ml·g ^-1 ·h ^-1 .

Table 2

T90 data of the catalyst RuO ₂ -SnTiO _x prepared in Example 3 and the commercially available Pd catalyst, Pt catalyst and Rh catalyst using TiO ₂ as a support under the same catalytic conversion of chlorobenzene test conditions

It can be seen from the data in Table 2 that the catalyst RuO ₂ -SnTiO _x prepared in Example 3 of the present invention has the lowest T90 and has good application prospects.

The above descriptions are only preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and changes. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention shall be included in the protection scope of the present invention.

Claims (10)

1. Catalyst RuO ₂ -SnTiO _x Is characterized by comprising the following steps:

step S1, preparing a carrier SnTiO _x ；

Adding a tin source and a titanium source into water and stirring for 1-2h to obtain a first mixed solution; wherein the mol ratio of tin element in the tin source to titanium element in the titanium source is 1-3:2-4;

adding the precipitant into water, stirring to dissolve, adding the first mixed solution, stirring for 1-2 hr, filtering, washing, and drying to obtain SnTiO _x A precursor;

SnTiO _x Calcining the precursor at 450-550 ℃ for 4-6 h to obtain the carrier SnTiO _x The method comprises the steps of carrying out a first treatment on the surface of the Wherein, the value of x is 4-6;

step S2, preparing a catalyst RuO ₂ -SnTiO _x

Adding ruthenium source into water, and adding carrier SnTiO _x And surfactant, stirring for 1-2h, filtering, washing, and drying to obtain RuO ₂ -SnTiO _x A precursor; wherein, the ruthenium source and the carrier SnTiO _x And surfactant in a mass ratio of 0.5-3:100:16.5;

RuO is to be made into ₂ -SnTiO _x Calcining the precursor at 450-550 deg.c for 4-6 hr to obtain RuO catalyst ₂ -SnTiO _x 。

2. The catalyst RuO according to claim 1 ₂ -SnTiO _x Is characterized in that it is carried out in the presence of RuO as a catalyst ₂ -SnTiO _x RuO of (C) ₂ The loading of (2) is 0.5-3wt%.

3. The catalyst RuO according to claim 1 ₂ -SnTiO _x Characterized in that the tin source comprises at least one of stannous chloride and tin acetate; the titanium source comprises at least one of tetrabutyl titanate and metatitanic acid; the ruthenium source includes at least one of ruthenium acetate and ruthenium chloride.

4. The catalyst RuO according to claim 1 ₂ -SnTiO _x The preparation method is characterized in that the precipitant comprises at least one of ammonium bicarbonate, ammonia water and sodium hydroxide.

5. The catalyst RuO according to claim 1 ₂ -SnTiO _x Is characterized in that the surfactant comprises at least one of cyclodextrin, polyvinylpyrrolidone and fullerene.

6. The catalyst RuO according to claim 1 ₂ -SnTiO _x The preparation method is characterized in that the drying condition parameters adopted in the steps S1-S2 are that the drying temperature is 80-100 ℃ and the drying time is 8-12h.

7. The catalyst RuO according to claim 1 ₂ -SnTiO _x The preparation method is characterized in that in the step S1-S2, the temperature is raised by adopting the temperature raising rate of 3-5 ℃/min of calcining condition parameters.

8. Catalyst RuO ₂ -SnTiO _x Characterized in that the catalyst RuO according to any of claims 1 to 7 ₂ -SnTiO _x Is prepared by the preparation method of (2).

9. Catalyst RuO ₂ -SnTiO _x Is characterized in that the catalyst RuO according to claim 8 is used ₂ -SnTiO _x The method is applied to catalytic conversion of chlorinated volatile organic compounds.

10. The catalyst RuO of claim 9 ₂ -SnTiO _x Is characterized in that the catalyst RuO ₂ -SnTiO _x In the catalytic conversion of chlorinated volatile organic compounds, a reaction temperature of 330-550 ℃ is used.