1. Removing sulfur-containing volatile organic compoundsThe Ag + loaded hierarchical porous molecular sieve is characterized in that: to be loaded with Ag⁺The Ag + loaded hierarchical porous molecular sieve has both a mesoporous structure and a microporous structure.

2. The Ag + loaded hierarchical porous molecular sieve for removing sulfur-containing volatile organic compounds according to claim 1, which is characterized in that: ag + in the Ag + loaded hierarchical porous molecular sieve and sulfur-containing volatile organic compounds form Ag-S bonds.

3. The Ag + loaded hierarchical porous molecular sieve for removing sulfur-containing volatile organic compounds according to claim 1, which is characterized in that: the Ag + loaded hierarchical porous molecular sieve has both mesoporous structure and microporous structure and is loaded with Ag⁺The framework of the USY molecular sieve is the USY molecular sieve.

4. The Ag + loaded hierarchical porous molecular sieve for removing sulfur-containing volatile organic compounds according to claim 3, which is characterized in that: simultaneously has a mesoporous structure and a microporous structure and is loaded with Ag⁺In the USY molecular sieve, the molar ratio of silicon to aluminum is 10-30, and the specific surface area is 500-1000 m²·g^-1The ratio of the pore volume of the mesoporous structure to the pore volume of the microporous structure is 0.5-2.5; if the mass of the Ag + loaded hierarchical porous molecular sieve is recorded as 100 wt.%, then Ag in the Ag + loaded hierarchical porous molecular sieve⁺The mass percent is 2-10 wt.%.

5. The preparation method of the Ag < + > loaded hierarchical porous molecular sieve for removing sulfur-containing volatile organic compounds according to claim 1, which is characterized by comprising the following steps:

step 1, carrying out multistage pore channel modification on the USY molecular sieve by adopting an alkali treatment method: adding a commercial USY molecular sieve into a mixed alkali solution of sodium hydroxide and tetrapropylammonium hydroxide, heating at 50-80 ℃ and stirring for 0.2-1 h; then washing, filtering and drying the heated mixed solution; roasting the obtained solid at 400-600 ℃ for 2-12 h to obtain a multistage pore channel USY molecular sieve;

step 2, adopting an ion exchange method to carry out multi-stage hole alignmentAg by USY molecular sieve⁺Loading: adding 0.1-1.0 mol.L of multi-stage pore channel USY molecular sieve^-1AgNO of₃In the solution, after the solution is heated and stirred for 12-48 hours at the room temperature to 90 ℃, the obtained mixed solution is adsorbed, filtered and dried by adopting a solid powdery molecular sieve adsorbent, and then is roasted for 2-12 hours at the temperature of 400-600 ℃ to obtain Ag⁺And loading the multistage pore canal molecular sieve.

6. The method for preparing the Ag < + > loaded hierarchical porous molecular sieve for removing the sulfur-containing volatile organic compounds according to claim 5, is characterized in that: in the step 1, the molar ratio of sodium hydroxide to tetrapropylammonium hydroxide in the mixed alkali solution is 0.5-2; the total concentration of the mixed alkali solution is 0.1-0.5 mol/L.

7. The method for preparing the Ag < + > loaded hierarchical porous molecular sieve for removing the sulfur-containing volatile organic compounds according to claim 6, which is characterized in that: in the step 1, the molar ratio of sodium hydroxide to tetrapropylammonium hydroxide in the mixed alkali solution is 1; the total concentration of the mixed alkali solution is 0.2 mol/L; the heating temperature is 65 ℃, and the heating time is 0.5 h; the roasting temperature is 500 ℃, and the roasting time is 4 hours.

8. The method for preparing the Ag < + > loaded hierarchical porous molecular sieve for removing the sulfur-containing volatile organic compounds according to claim 5, is characterized in that: AgNO in step 2₃Ag of solution⁺The number is larger than the maximum ion exchange capacity of the multistage pore channel USY molecular sieve; AgNO in step 2₃The solution concentration is 0.5 mol.L^-1The temperature while heating and stirring is 80 ℃, the time period while heating and stirring is 24 hours, the roasting temperature is 500 ℃, and the roasting time period is 4 hours.

9. The method for preparing the Ag < + > loaded hierarchical porous molecular sieve for removing the sulfur-containing volatile organic compounds according to claim 5, is characterized in that: and replacing the solid powdery molecular sieve adsorbent in the step 2 with a spherical, granular or honeycomb molecular sieve adsorbent.

10. The application method of the Ag < + > loaded hierarchical porous molecular sieve for removing sulfur-containing volatile organic compounds according to claim 1, which is characterized in that: used for adsorbing sulfur-containing volatile organic compounds.

Background

VOCs widely exist in pharmaceutical, chemical and other industries, and in the industries, malodorous sulfur-containing VOCs, such as thioether, mercaptan and the like, are usually generated in the biochemical treatment process of a sewage station, and are important sources of PM2.5 and near-surface ozone. Meanwhile, the odor threshold of sulfur-containing VOCs is extremely low, for example, the odor threshold of dimethyl sulfide is 0.003ppm, which causes the environmental deterioration of production and living areas.

The VOCs control technology mainly includes recovery technologies represented by adsorption, absorption, membrane separation, condensation and the like, and destruction technologies represented by combustion (heat storage, catalysis), plasma, photocatalysis and the like. In practice, it is common to combine technologies to meet stringent emission standards. Wherein, it is one of the most common combination technique to combine the aftertreatment combination technique with the absorption, through the adsorption concentration, can be with the enrichment of low concentration VOCs for high concentration VOCs, the high-efficient economic improvement of VOCs waste gas is realized to technical means such as the follow-up adoption condensation of being convenient for, burning.

The currently commonly used adsorbents comprise activated carbon, molecular sieves and the like, wherein the activated carbon and the molecular sieves have the advantages of low cost, rich micropores and high VOCs adsorption capacity due to large specific surface area, but have the problems of difficult regeneration after adsorption, flammability and the like; the molecular sieve gradually replaces the activated carbon by the VOCs adsorption capacity close to that of the activated carbon and higher thermal stability, and becomes a research hotspot of VOCs adsorption concentration technology. The molecular sieve is a series of aluminosilicate materials capable of screening molecules, and the basic framework of the molecular sieve is made of SiO₄、AlO₄Tetrahedron and pore system with different dimensions are formed, and crystals with a net structure are formed by combining oxygen atoms, so that a large cavity is formed inside the molecular sieve, and a large number of molecules can be adsorbed and stored. Meanwhile, the molecular sieve structure also has molecular-level pore channels with uniform pore size distribution and regularly arranged pores, and different types of molecular sieves have different pore size ranges, so that the molecular sieves can effectively identify and sieve molecules with different sizes and shapes for adsorbates. Compared with activated carbon, the molecular sieve has slightly smaller adsorption capacity, higher thermal stability, capability of desorption and regeneration at higher temperature (for example, the mordenite molecular sieve can be destroyed at 900 ℃), and relatively lower energy consumption for molecular sieve desorption. The existing molecular sieve for adsorbing VOCs is a microporous molecular sieve, and a mesoporous molecular sieve has large pore channel size and extremely low adsorption capacity.

Since the sulfur-containing VOCs are usually only C₂Or C₃Molecules and smaller molecular sizes are not easy to be captured by the adsorbent, and the problems of low adsorption capacity, easy occupation of adsorption sites by other VOCs and the like exist no matter the activated carbon or the molecular sieve is used for adsorbing the sulfur-containing VOCs. Thus, the prepared volatile organic compounds have higher adsorption capacity of sulfur-containing VOCsThe adsorbent has important application value.

Disclosure of Invention

The invention aims to overcome the defects in the prior art and provides an Ag < + > loaded multistage pore molecular sieve for removing sulfur-containing volatile organic compounds, a preparation method and application thereof.

The Ag + loaded multi-stage pore canal molecular sieve for removing sulfur-containing volatile organic compounds is loaded with Ag⁺The Ag + loaded hierarchical porous molecular sieve has both a mesoporous structure and a microporous structure.

Preferably, Ag + in the Ag + loaded hierarchical porous molecular sieve and sulfur-containing volatile organic compounds form Ag-S bonds, so that the original physical adsorption is changed into chemical adsorption, sulfur-containing VOCs are prevented from being squeezed by other adsorbates to occupy adsorption sites, and the adsorption capacity of the molecular sieve on the sulfur-containing VOCs is greatly enhanced.

Preferably, the Ag + loaded hierarchical porous molecular sieve has both a mesoporous structure and a microporous structure and is loaded with Ag⁺The framework of the USY molecular sieve is the USY molecular sieve.

Preferably, the Ag-supported mesoporous material has both a mesoporous structure and a microporous structure⁺The USY molecular sieve has a Si/Al molar ratio of 10-30 (e.g., 10, 12, 14, 16, 18, 20, 22, 24, 26, 28 or 30) and a specific surface area of 500-1000 m²·g^-1The ratio of the mesoporous volume to the microporous volume is 0.5-2.5 (e.g., 0.5, 1, 1.5, 2 or 2.5); if the mass of the Ag + loaded hierarchical porous molecular sieve is recorded as 100 wt.%, then Ag in the Ag + loaded hierarchical porous molecular sieve⁺The mass percent is 2-10 wt.%.

The preparation method of the Ag + loaded hierarchical porous molecular sieve for removing the sulfur-containing volatile organic compounds comprises the following steps:

step 1, carrying out multistage pore channel modification on the USY molecular sieve by adopting an alkali treatment method: adding a commercial USY molecular sieve into a mixed alkali solution of sodium hydroxide (NaOH) and tetrapropylammonium hydroxide (TPAOH), heating and stirring for 0.2-1 h, such as 0.2h, 0.3h, 0.4h, 0.5h, 0.6h, 0.7h, 0.8h, 0.9h or 1h, at 50-80 ℃ (such as 50 ℃, 55 ℃, 65 ℃, 70 ℃, 75 ℃ or 80 ℃); then washing, filtering and drying the heated mixed solution; roasting the obtained solid for 2-12 h (for example, 2h, 4h, 6h, 8h, 10h or 12h) at 400-600 ℃ (for example, 400 ℃, 450 ℃, 500 ℃, 550 ℃ and 600 ℃) to obtain the hierarchical pore USY molecular sieve, and removing organic groups attached to the surface of the molecular sieve through high-temperature roasting; the heating temperature and the heating time are reasonably controlled, and the proportion of the mesoporous structure in the molecular sieve can be effectively regulated and controlled;

step 2, carrying out Ag on the multi-stage pore channel USY molecular sieve by adopting an ion exchange method⁺Loading: adding 0.1-1.0 mol.L of multi-stage pore channel USY molecular sieve^-1(e.g., 0.1 mol. L)^-1、0.2mol·L^-1、0.3mol·L^-1、0.4mol·L^-1、0.5mol·L^-1、0.6mol·L^-1、0.7mol·L^-1、0.8mol·L^-1、0.9mol·L^-1Or 0.1 mol. L^-1) AgNO of₃Heating the solution at room temperature to 90 deg.C (such as 30 deg.C, 40 deg.C, 50 deg.C, 60 deg.C, 70 deg.C, 80 deg.C or 90 deg.C) while stirring for 12-48 h (such as 12h, 24h, 36h or 48h), adsorbing the obtained mixed solution with solid powdery molecular sieve adsorbent, filtering, drying, and calcining at 400-600 deg.C (such as 400 deg.C, 450 deg.C, 500 deg.C, 550 deg.C, 600 deg.C) for 2-12 h (such as 2h, 4h, 6h, 8h, 10h or 12h) to obtain Ag⁺And loading the multistage pore canal molecular sieve.

Preferably, the molar ratio of sodium hydroxide (NaOH) to tetrapropylammonium hydroxide (TPAOH) in the mixed alkaline solution in step 1 is 0.5 to 2 (e.g. 0.5, 1, 1.5 or 2); the total concentration of the mixed alkali solution is 0.1 to 0.5mol/L (for example, 0.1, 0.2, 0.3, 0.4 or 0.5 mol/L).

Preferably, the molar ratio of sodium hydroxide (NaOH) to tetrapropylammonium hydroxide (TPAOH) in the mixed alkali solution in step 1 is 1; the total concentration of the mixed alkali solution is 0.2 mol/L; the heating temperature is 65 ℃, and the heating time is 0.5 h; the roasting temperature is 500 ℃, and the roasting time is 4 hours.

Preferably, AgNO in step 2₃Ag of solution⁺The quantity is larger than the theoretical maximum ion exchange quantity of the multistage pore channel USY molecular sieve; AgNO in step 2₃The solution concentration is 0.5 mol.L^-1Stirring while heatingThe temperature of the furnace is 80 ℃, the time for stirring while heating is 24 hours, the roasting temperature is 500 ℃, and the roasting time is 4 hours.

Preferably, the solid powdery molecular sieve adsorbent in step 2 is replaced by spherical, granular or honeycomb molecular sieve adsorbent with different sizes.

The application method of the Ag & lt + & gt-loaded hierarchical porous molecular sieve for removing sulfur-containing volatile organic compounds comprises the following steps: the adsorbent is used for adsorbing various VOCs (volatile organic compounds) including sulfur-containing volatile organic compounds such as thioether and mercaptan.

The invention has the beneficial effects that:

the Ag for removing the sulfur-containing VOCs provided by the invention⁺In the molecular sieve loaded with multilevel pore channels, Ag⁺Can form Ag-S bonds with sulfur-containing VOCs, so that the original physical adsorption is changed into chemical adsorption, the sulfur-containing VOCs are prevented from being extruded by other adsorbates to occupy adsorption sites, and the adsorption capacity of the molecular sieve on the sulfur-containing VOCs is greatly enhanced;

secondly, the molecular sieve uses a high-silicon USY (ultra-stable Y) molecular sieve as a framework, and a mesoporous structure is formed in the microporous molecular sieve through alkali treatment modification; the invention adopts the multilevel pore canal molecular sieve which simultaneously has a mesoporous structure and a microporous structure, and can strengthen the mass transfer in the molecular sieve; and loading Ag by ion exchange⁺Enhancing the adsorption of the molecular sieve to the sulfur-containing VOCs;

compared with the prior art, the invention avoids the problems of pore channel blockage and molecular sieve adsorption capacity reduction caused by that small molecular sulfur-containing VOCs rapidly enter the molecular sieve and are combined with adsorption sites, and greatly improves the adsorption capacity of the traditional high-silicon molecular sieve for sulfur-containing VOCs; the problems that desorption of sulfur-containing VOCs is caused by competitive adsorption of multi-component VOCs on a traditional high-silicon molecular sieve, and the common ion exchange molecular sieve is difficult to adsorb the common VOCs due to selective adsorption of the sulfur-containing VOCs are solved, so that the multi-component VOCs including the sulfur-containing VOCs can be efficiently adsorbed at the same time.

Drawings

FIG. 1 is a schematic diagram of the structures of molecular sieves of examples and comparative examples of the present invention;

FIG. 2 is a comparison diagram of the penetration adsorption amount when DMS and PX are simultaneously adsorbed on NaY, USY, AgY, AgUSY and AgUSY-M molecular sieves under the moisture condition.

Detailed Description

The present invention will be further described with reference to the following examples. The following examples are set forth merely to aid in the understanding of the invention. It should be noted that, for a person skilled in the art, several modifications can be made to the invention without departing from the principle of the invention, and these modifications and modifications also fall within the protection scope of the claims of the present invention.

Example one

The first embodiment of the present application provides an Ag + loaded hierarchical porous molecular sieve (AgUSY-H) for removing sulfur-containing volatile organic compounds as shown in fig. 1 (e).

Ag is loaded on the multistage pore canal molecular sieve in an ion exchange mode⁺The adsorption of sulfur-containing volatile organic compounds is realized; the Ag + loaded multistage pore molecular sieve has a mesoporous structure and a microporous structure simultaneously, so that the transfer of adsorbates in the molecular sieve can be enhanced, and the problems that small molecular sulfur-containing VOCs rapidly enter the molecular sieve and are combined with adsorption sites to cause pore blockage, the adsorption capacity of the molecular sieve is reduced, and the molecular sieve cannot realize the simultaneous high-efficiency adsorption of multi-component VOCs due to the fact that small molecular sulfur-containing VOCs occupy the adsorption sites of other VOCs and the like are solved; there is usually a certain amount of H in the actual VOCs exhaust₂O, hydrophobic molecular sieve with high silica-alumina molar ratio, such as USY, ZSM-5, Silicalite-1 (all-silica molecular sieve), etc., is adopted to avoid H₂The problem that VOCs cannot be adsorbed due to O competitive adsorption; the basic skeleton of the molecular sieve is made of SiO₄、AlO₄The molecular sieve is composed of a tetrahedron and a pore system with different dimensions, and compensation ions are needed outside a framework of the molecular sieve because of lower aluminum valence state to maintain the electric neutrality of the molecular sieve; the compensation ions outside the framework are easily exchanged by other ions in an ion exchange mode, so that the uniform load of the modified ions is realized; the above properties of molecular sieves determine that the molecular sieves need to have both an increased silica to alumina molar ratio and a certain ion exchange capacity.

In practical application, a plurality of VOCs exist, and competitive adsorption may exist among different VOCs. For example, Paraxylene (PX) has a larger molecular weight and is easier to adsorb, and can occupy the dimethyl sulfide (DMS) adsorption sites by extrusion, so that the adsorption capacity of the molecular sieve for DMS is reduced; after the molecular sieve is subjected to Ag + load modification, DMS has a higher diffusion rate in micropores and forms stable chemical adsorption with Ag +, a large number of adsorption sites are occupied, pore channels of the molecular sieve are blocked, the total adsorption capacity is reduced, and PX cannot be adsorbed simultaneously. Therefore, when Ag + is loaded, a mesoporous structure is introduced into the molecular sieve, the adsorption of sulfur-containing VOCs can be enhanced, the mass transfer of VOCs can be enhanced, and the simultaneous high-efficiency adsorption of multi-component VOCs is realized. Generally, commercial USY molecular sieves are prepared by dealuminating a Y-type molecular sieve, which has a mesoporous structure (usually less than 50%) but still has a low proportion, and needs to be further promoted.

The framework of the molecular sieve in the example is USY molecular sieve, the mole ratio of silicon to aluminum is 17.3, and the specific surface area is 734.7m²·g^-1The ratio of the mesoporous volume to the microporous volume is 2.18, Ag⁺The mass percentage was 7.1 wt.%. The molecular sieve is in H₂Simultaneously adsorbing dimethyl sulfide (DMS) and Paraxylene (PX) under the condition that the O content volume fraction is 1.5%, wherein the penetrating adsorption capacity of DMS and PX is 57mg g^-1And 114mg g^-1。

Example two

The second embodiment of the present application provides Ag in the first embodiment⁺The preparation method of the loaded USY molecular sieve (AgUSY-H) comprises the following steps:

1. the USY-3 molecular sieve is subjected to multistage pore channel modification by adopting an alkali treatment method:

adding a commercial USY-3 molecular sieve into a mixed alkali solution, heating and stirring, washing, filtering, drying and roasting to obtain a multi-stage pore channel USY molecular sieve; the USY molecular sieve dissolves Si in a molecular sieve framework through alkali treatment, so that a large number of mesoporous structures are formed in the molecular sieve, the dissolution rate needs to be controlled, the molecular sieve framework can be completely damaged due to excessive dissolution, TPAOH contains organic groups, and the TPAOH can be attached to the surface of the molecular sieve, so that the molecular sieve is protected in the dissolution process.

2. Carrying out Ag on commercial USY molecular sieve by adopting ion exchange method⁺Loading:

adding the multi-level pore channel modified USY-3 molecular sieve into 0.5 mol.L-1 AgNO3 solution (the quantity of Ag + ions is more than the theoretical maximum ion exchange quantity of the USY molecular sieve), heating and stirring for 24 hours at 80 ℃, adsorbing, filtering and drying the obtained mixed solution by using a solid powdery molecular sieve adsorbent, and finally roasting for 4 hours at 500 ℃ to obtain the AgUSY molecular sieve. The excess Ag + ions in the AgNO3 solution increases the ion exchange temperature, ensures the ion exchange time and ensures the complete ion exchange of the molecular sieve. The reasonable selection of the roasting parameters ensures that the combination of Ag + and the molecular sieve is more firm.

The solid powdery molecular sieve adsorbent can be made into various structural shapes according to actual requirements, for example, the molecular sieve adsorbent can be made into spheres, granules, honeycombs and the like with different sizes.

The silicon-aluminum molar ratio of the AgUSY-H molecular sieve is 17.3, and the specific surface area is 734.7m²·g^-1The ratio of the mesoporous volume to the microporous volume is 2.18, Ag⁺The mass percent is 7.1 wt.%, and the structural diagram is shown in fig. 1 (e).

As shown in FIG. 2, in the process of adsorbing DMS and PX simultaneously by AgUSY-H molecular sieve, the penetrating adsorption amounts of DMS and PX are 57mg g^-1And 114mg g^-1This shows that AgUSY-H molecular sieve can realize the simultaneous high-efficiency adsorption of multi-component VOCs, and the main reason is Ag⁺The adsorption of DMS can be obviously enhanced, the AgUSY-H molecular sieve has more mesoporous structures, and the utilization efficiency of the adsorption sites in the molecular sieve is higher (AgUSY-H molecular sieve Ag)⁺The loading capacity is lower than that of the AgUSY-1 molecular sieve, but the adsorption capacity for DMS is larger, see comparative examples 4-6), and PX can also diffuse into the AgUSY-H molecular sieve to realize adsorption.

Comparative example 1

On the basis of the second example, the comparative example specifically provides a modified Ag alloy which is not subjected to alkali treatment⁺A loaded commercial NaY molecular sieve (NaY) with a silica to alumina molar ratio of 2.7 and a specific surface area of 931.2m²·g^-1The ratio of the mesopore volume to the micropore volume is 0.11, and the structural schematic diagram is shown in fig. 1 (a).

As shown in FIG. 2, the NaY molecular sieve adsorbs simultaneouslyDMS and PX almost instantaneously penetrate in the process of adsorbing DMS and PX, because the NaY molecular sieve has lower regular molar ratio and is subjected to H in the process of adsorbing VOCs₂The O effect is large, resulting in almost no adsorption of VOCs.

Comparative example No. two

On the basis of example two, this comparative example specifically provides an Ag that has not been modified by alkali treatment⁺The preparation process of the loaded NaY molecular sieve (AgY) comprises the following steps:

carrying out Ag on commercial NaY molecular sieve by adopting ion exchange method⁺Loading, adding commercial NaY molecular sieve into 0.5 mol.L^-1AgNO of₃In solution (Ag)⁺The ion quantity is larger than the theoretical maximum ion exchange quantity of the NaY molecular sieve), heating and stirring for 24 hours at 80 ℃, washing, filtering, drying, and finally roasting for 4 hours at 500 ℃ to obtain the AgY molecular sieve.

The silicon-aluminum molar ratio of the AgY molecular sieve is 2.7, and the specific surface area is 603.4m²·g^-1The ratio of the mesoporous volume to the microporous volume is 0.55, Ag⁺The mass percent is 29.1 wt.%, and the structural diagram is shown in fig. 1 (b).

As shown in FIG. 2, in the process of adsorbing DMS and PX simultaneously by the AgY molecular sieve, the penetrating adsorption amounts of DMS and PX are 81mg g^-1And 15mg g^-1This indicates that Ag is on the AgY molecular sieve⁺There is a significant enhancement of DMS adsorption, but it is too low for PX adsorption.

Comparative example No. three

On the basis of the second example, the comparative example specifically provides a modified Ag alloy without alkali treatment⁺Loaded commercial USY molecular sieve (USY-3).

The USY-3 molecular sieve has the silica-alumina molar ratio of 20.5 and the specific surface area of 879.3m²·g^-1The ratio of the mesoporous volume to the microporous volume is 0.79, and the structural schematic diagram is shown in fig. 1 (c).

As shown in FIG. 2, in the process of simultaneously adsorbing DMS and PX by using the commercial USY molecular sieve, the penetrating adsorption amounts of DMS and PX are respectively 0mg g^-1And 127mg g^-1PX severely occupies DMS adsorption sites, resulting in inability of DMS adsorption.

Comparative example No. four

On the basis of example two, this comparative example specifically provides an Ag that has not been modified by alkali treatment⁺The preparation process of the loaded USY molecular sieve (AgUSY-1) comprises the following steps: carrying out Ag on commercial USY-1 molecular sieve by adopting an ion exchange method⁺Loading, adding commercial USY-1 molecular sieve into 0.5 mol.L^-1AgNO of₃In solution (Ag)⁺The ion quantity is larger than the theoretical maximum ion exchange quantity of the USY-1 molecular sieve), heating and stirring for 24 hours at 80 ℃, washing, filtering, drying, and finally roasting for 4 hours at 500 ℃ to obtain the AgUSY-1 molecular sieve.

The silicon-aluminum molar ratio of the AgUSY-1 molecular sieve is 7.0, and the specific surface area is 821.3m²·g^-1The ratio of the mesoporous volume to the microporous volume is 0.75, Ag⁺The mass percent is 9.9 wt.%, and the structural diagram is shown in fig. 1 (d).

As shown in FIG. 2, in the process of adsorbing DMS and PX simultaneously by AgUSY-1 molecular sieve, the penetrating adsorption amounts of DMS and PX are respectively 55mg g^-1And 83mg g^-1This indicates that the molecular sieve of AgUSY-1 is due to Ag⁺The USY molecular sieve has a certain mesoporous structure compared with the NaY molecular sieve, and the mass transfer capacity in the molecular sieve is superior to that of the NaY or AgY molecular sieve, so that the AgUSY-1 molecular sieve can realize simultaneous adsorption of PX.

Comparative example five

On the basis of example two, this comparative example specifically provides an Ag that has not been modified by alkali treatment⁺The preparation process of the loaded USY molecular sieve (AgUSY-2) comprises the following steps: carrying out Ag on commercial USY-2 molecular sieve by adopting ion exchange method⁺Loading, adding commercial USY-2 molecular sieve into 0.5 mol.L^-1AgNO of₃In solution (Ag)⁺The ion quantity is larger than the theoretical maximum ion exchange quantity of the USY-2 molecular sieve), heating and stirring for 24 hours at 80 ℃, washing, filtering, drying, and finally roasting for 4 hours at 500 ℃ to obtain the AgUSY-2 molecular sieve.

The silicon-aluminum molar ratio of the AgUSY-2 molecular sieve is 17.4, and the specific surface area is 850.5m²·g^-1The ratio of the mesoporous volume to the microporous volume is 0.81, Ag⁺Mass hundredThe percentage is 5.5 wt.%, and the structure diagram is shown in fig. 1 (d).

As shown in FIG. 2, in the process of adsorbing DMS and PX simultaneously by AgUSY-2 molecular sieve, the penetrating adsorption amounts of DMS and PX are 45mg g^-1And 96mg g^-1. As the USY-2 molecular sieve has a higher Si/Al molar ratio than the USY-1 molecular sieve and has a lower Ag + ion exchange amount, the AgUSY-2 molecular sieve has reduced adsorption of DMS, but the PX adsorption amount is increased, and the total adsorption capacity of the AgUSY-2 molecular sieve and the PX adsorption amount is increased.

Comparative example six

On the basis of example two, this comparative example specifically provides an Ag that has not been modified by alkali treatment⁺The preparation process of the loaded USY molecular sieve (AgUSY-3) comprises the following steps: carrying out Ag on commercial USY-3 molecular sieve by adopting ion exchange method⁺Loading, adding commercial USY-3 molecular sieve into 0.5 mol.L^-1AgNO of₃In solution (Ag)⁺The ion quantity is larger than the theoretical maximum ion exchange quantity of the USY-3 molecular sieve), heating and stirring for 24 hours at 80 ℃, washing, filtering, drying, and finally roasting for 4 hours at 500 ℃ to obtain the AgUSY-3 molecular sieve.

The silicon-aluminum molar ratio of the AgUSY-3 molecular sieve is 20.8, and the specific surface area is 767.4m²·g^-1The ratio of the mesoporous volume to the microporous volume is 1.13, Ag⁺The mass percent is 5.2 wt.%, and the structural diagram is shown in fig. 1 (d).

As shown in FIG. 2, in the process of adsorbing DMS and PX simultaneously by AgUSY-3 molecular sieve, the penetrating adsorption amounts of DMS and PX are 40mg g^-1And 110mg g^-1. As the Si/Al molar ratio of the USY-3 molecular sieve is further improved compared with that of the USY-2 molecular sieve, Ag of the USY-3 molecular sieve⁺The ion exchange number is further reduced and thus AgUSY-3 molecular sieve adsorbs less DMS, higher PX, and has a greater overall adsorption capacity for both, but lower than AgUSY-M molecular sieve for both DMS and overall adsorption capacities.

As can be seen from the results of table 1 below in combination with the above examples and comparative examples, the present invention greatly increases the adsorption capacity of the conventional high-silicon molecular sieve for sulfur-containing VOCs, and can simultaneously and efficiently adsorb multi-component VOCs, thereby avoiding the desorption of adsorbed components due to competitive adsorption.

TABLE 1 basic parameter tables of NaY, USY, AgY, AgUSY-H molecular sieves

Adsorbent and process for producing the same	Total specific surface area m2·g-1	Meso pore volume/micro pore volume	Silicon to aluminum ratio	Ag+Loading amount wt. -%)
					NaY	931.2	0.11	2.7	/
USY-1	910.3	0.65	6.1	/
					USY-2	885.4	0.61	15.6	/
USY-3	879.3	0.79	20.5	/
					AgY	603.4	0.55	2.7	29.1
AgUSY-1	821.3	0.75	7.0	9.9
					AgUSY-2	850.5	0.81	17.4	5.5
AgUSY-3	767.4	1.13	20.8	5.2
					AgUSY-H	734.7	2.18	17.3	7.1