Modified activated carbon, preparation method thereof, catalyst and application of catalyst

Abstract

The invention provides modified activated carbon and a preparation method thereof, a catalyst and application thereof, the modified activated carbon comprises an activated carbon matrix, the activated carbon matrix comprises a plurality of micropores and a plurality of mesopores, and at least part of the micropores are combined with a modifier through chemical bonds; and the following conditions are satisfied: T1lt; t2, 0.4 < = S1 / S2 < = 0.6, 0.8 < = S3 / S4 < = 1; wherein T1 is the decomposition temperature of the modifier, T2 is the initial decomposition temperature of the activated carbon matrix, S1 is the micropore specific surface area of the modified activated carbon, S2 is the micropore specific surface area of the modified activated carbon roasted at the temperature larger than T1 and smaller than T2, and S3 is the mesoporous specific surface area of the modified activated carbon. S4 is the mesoporous specific surface area of the modified activated carbon after roasting at the temperature greater than T1 and less than T2. According to the invention, the modifier is combined in the micropore channels of the activated carbon matrix, so that the occupation of the micropore channels is realized, and the pore channel property of the activated carbon is accurately controlled.

Description

Technical Field

[0001] The present invention relates to the field of activated carbon modification, and in particular to modified activated carbon, a preparation method thereof, a catalyst and applications thereof. Background Art

[0002] Activated carbon is a common adsorbent and a common catalyst carrier material. Activated carbon is rich in microporous, mesoporous and macroporous pore structures. In order to meet different application scenarios, it is generally necessary to modify the pore structure of activated carbon. The current modification technologies for the pore structure of activated carbon mainly include acid-base modification, redox modification and adsorption modification. Among them, the acid-base modification process usually involves hazardous chemicals with corrosive properties; redox modification is usually achieved by treating redox substances under strong acid and alkali conditions at a certain temperature. The process is not green and environmentally friendly and is not conducive to industrial scale-up production; whether the adsorption modification process is environmentally friendly mainly depends on the chemical characteristics of the adsorbed substance. Although the current modification technology has successfully modified the surface properties of activated carbon, it cannot accurately control the changes in pore properties.

[0003] Achieving precise control over the pore properties of activated carbon will help improve the utilization rate of the loaded catalyst. Taking the hydrogenation reaction process of bisphenol A with a larger molecular size as an example, bisphenol A molecules and hydrogen molecules need to diffuse to the vicinity of the active center of the catalyst during the reaction, and then hydrogenation reaction occurs within a certain area to generate the target product of hydrogenated bisphenol A. However, the width of bisphenol A molecules is large and it is difficult for them to enter the micropore channels. The micropore specific surface area of ​​conventional activated carbon accounts for about 60% of the total specific surface area. If conventional activated carbon is used as a carrier and the catalyst is loaded by the impregnation method, a large amount of active phase will adhere to the micropore channels, and bisphenol A molecules will find it difficult to diffuse into the micropore channels. Ultimately, the active phase in the micropore channels cannot be fully utilized, and the total utilization rate of the active phase is low, thereby reducing the catalytic activity of the catalyst. Summary of the Invention

[0004] The present invention provides a modified activated carbon. The modified activated carbon is prepared by combining a modifier in micropore channels so that the modifier blocks the micropore channels in the activated carbon, thereby achieving the goal of regulating the ratio of the micropore specific surface area of ​​the activated carbon matrix to the total specific surface area.

[0005] The present invention also provides a method for preparing the modified activated carbon. The method can prepare the modified activated carbon and has a simple process.

[0006] The present invention also provides a catalyst. Since the catalyst uses the above-mentioned modified activated carbon as a carrier, the active phase can be mainly loaded in the mesoporous pores, thereby increasing the contact probability between raw materials with larger molecular sizes and the active phase, thereby improving the catalytic performance of the catalyst.

[0007] The present invention also provides another catalyst. Since this catalyst is prepared using the above-mentioned modified activated carbon, this catalyst not only helps to increase the probability of contact between raw materials with larger molecular sizes and the active phase, but also reopens the micropore channels of the modified activated carbon through calcination, improving the total pore volume and specific surface area of the modified activated carbon, thereby further enhancing the catalytic activity of the catalyst.

[0008] The present invention also provides a method for catalytic hydrogenation of bisphenol A to prepare hydrogenated bisphenol A. Since this method uses any of the above-mentioned catalysts for catalysis, this method helps to improve the conversion rate of bisphenol A.

[0009] First aspect, the present invention provides a modified activated carbon, including an activated carbon matrix, the activated carbon matrix includes a number of micropores and a number of mesopores, wherein at least part of the micropores are chemically bonded with a modifier; and the modified activated carbon satisfies the following formulas 1 to 3:

[0010] T1 < T2 Formula 1,

[0011] 0.4 ≤ S1 / S2 ≤ 0.6 Formula 2,

[0012] 0.8 ≤ S3 / S4 ≤ 1 Formula 3;

[0013] Wherein, T1 is the decomposition temperature of the modifier, T2 is the initial decomposition temperature of the activated carbon matrix, S1 is the micropore specific surface area of the modified activated carbon, S2 is the micropore specific surface area of the modified activated carbon after calcination at a temperature greater than T1 and less than T2, S3 is the mesopore specific surface area of the modified activated carbon, and S4 is the mesopore specific surface area of the modified activated carbon after calcination at a temperature greater than T1 and less than T2.

[0014] Preferably, the modifier is an amino acid;

[0015] And / or, the modifier contains one or more of amidino, benzyl, and mercapto functional groups.

[0016] Preferably, the modifier is one or more of arginine, phenylalanine, and methionine.

[0017] Preferably, the mesopore specific surface area of the modified activated carbon accounts for more than 50% of the total specific surface area;

[0018] And / or, the micropore specific surface area of the modified activated carbon accounts for less than 50% of the total specific surface area.

[0019] Preferably, T2 - T1 ≥ 50°C.

[0020] Second aspect, the present invention provides a preparation method of the above-mentioned modified activated carbon, including the following steps:

[0021] A mixed system comprising an activated carbon matrix, a modifier and a solvent is stirred at 20-80° C. for 0.5-3 hours, filtered and dried to obtain the product; wherein the pH of the mixed system is 6-10.

[0022] In a third aspect, the present invention provides a catalyst comprising a carrier and an active ingredient supported on the carrier, wherein the carrier is the modified activated carbon described above; the active ingredient is at least partially supported in the mesopores of the modified activated carbon;

[0023] And / or, the active ingredient includes ruthenium trichloride.

[0024] In a fourth aspect, the present invention provides a catalyst prepared by a method comprising the following steps:

[0025] The active ingredient is loaded into the mesopores of the modified activated carbon through an impregnation treatment to obtain an intermediate; the intermediate is calcined at a temperature greater than T1 and less than T2 to remove the modifier to obtain the catalyst.

[0026] In a fifth aspect, the present invention provides a method for catalytic hydrogenation of chemical monomers containing benzene rings, wherein the catalyst comprises the catalyst of any of the above aspects.

[0027] Preferably, the benzene ring-containing chemical monomer is bisphenol A.

[0028] The modified activated carbon provided by the present invention achieves microporous pore occupancy by incorporating a modifier into the micropores of the activated carbon matrix, thereby regulating the ratio of the micropore specific surface area of ​​the activated carbon matrix to the total specific surface area. Therefore, during the preparation of a catalyst using the modified activated carbon as a support, the active phase adheres less to the micropore surfaces of the activated carbon support and more to the mesopore surfaces of the support. This increases the probability of contact between larger raw material molecules and the active phase, thereby enhancing the catalytic activity of the catalyst.

[0029] Furthermore, the modifier used in the modified activated carbon of the present invention has a relatively low decomposition temperature. Optionally, the microporous channel structure of the activated carbon matrix is ​​restored in the subsequent catalyst treatment process, thereby increasing the total pore volume and specific surface area of ​​the modified activated carbon. Taking the hydrogenation reaction process of bisphenol A as an example, the increase in total pore volume and specific surface area is conducive to creating a state of excess hydrogen molecules around the active phase during the reaction process, which can further enhance the catalytic activity of the catalyst. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention.

[0031] Figure 1The UV spectra of the aqueous solution of the activated carbon substrate A0 before and after modification and the filtrate of the modified activated carbon A1 after washing are shown in FIG.

[0032] Figure 2 These are the thermogravimetric characterization diagrams of activated carbon matrix A0 and modified activated carbon A1 in air atmosphere. DETAILED DESCRIPTION

[0033] In order to enable those skilled in the art to better understand the scheme of the present invention, the present invention is further described in detail below. The specific embodiments listed below are only for describing the principles and features of the present invention. The examples are only used to explain the present invention and are not intended to limit the scope of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts are within the scope of protection of the present invention.

[0034] In this application, the term "and / or" describes the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone, where A and B can be singular or plural. The character " / " generally indicates that the previous and subsequent associated objects are in an "or" relationship.

[0035] In this application, the term "at least one" means one or more, and "plurality" means two or more. "At least one of the following" or similar expressions refers to any combination of these items, including any combination of single items or plural items. For example, "at least one of a, b, or c" or "at least one of a, b, and c" can all mean: a, b, c, ab (i.e., a and b), ac, bc, or abc, where a, b, and c can be single or multiple.

[0036] In this application, the term "micropores" refers to pores with a pore diameter of less than 2 nm; the term "mesopores" refers to pores with a pore diameter in the range of 2-50 nm; and the term "macropores" refers to pores with a pore diameter of >50 nm.

[0037] In this application, the term "bisphenol A", also known as BPA, diphenol propane, p,p'-isopropylidene bisphenol, 2,2-bis-p-phenol propane or 2,2-bis(4-hydroxyphenyl)propane, is an organic compound with the molecular formula C 15 H 16 O2.

[0038] In this application, the micro / mesoporous specific surface area or the total specific surface area of ​​the modified activated carbon can be obtained by a specific surface and porosity analyzer (BET) test.

[0039] In order to precisely control the pore properties of activated carbon, specifically, in order to precisely control the proportion of the micropore specific surface area of activated carbon in the total specific surface area, the present invention adopts the following technical solutions:

[0040] In a first aspect, the present invention provides a modified activated carbon, comprising an activated carbon matrix, wherein the activated carbon matrix comprises a plurality of micropores and a plurality of mesopores, and at least part of the micropores are chemically bonded with a modifier; and the modified activated carbon satisfies the following formulas 1 and 2:

[0041] T1 < T2 Formula 1,

[0042] 0.4 ≤ S1 / S2 ≤ 0.6 Formula 2;

[0043] 0.8 ≤ S3 / S4 ≤ 1 Formula 3;

[0044] Wherein, T1 is the decomposition temperature of the modifier, T2 is the initial decomposition temperature of the activated carbon matrix, S1 is the micropore specific surface area of the modified activated carbon, S2 is the micropore specific surface area of the modified activated carbon after calcination at a temperature greater than T1 and less than T2, S3 is the mesopore specific surface area of the modified activated carbon, and S4 is the mesopore specific surface area of the modified activated carbon after calcination at a temperature greater than T1 and less than T2.

[0045] It should be noted that the comparisons of T1, T2, S2, and S4 are all required to be carried out in an oxygen-containing atmosphere. Exemplarily, the above T1 and T2 can be obtained through thermogravimetric analysis (TG) tests. In the TG curve of the modifier corresponding to T1, it is not less than the temperature value corresponding to the maximum weight loss rate. Further, to ensure the complete decomposition of the modifier, T1 is preferably not greater than the temperature value corresponding to the maximum reduction point (the maximum reduction point: when the substance loses weight, at a certain temperature, the weight data begins to level off and hardly shows weight loss). For example, in actual tests, 20 mg of the modifier is taken, and the temperature is increased at a rate of 20 °C / min in an air atmosphere. The temperature range corresponding to the weight reduction of the modifier is observed, and the temperature at which the weight decreases fastest in the range is recorded as the temperature value corresponding to the maximum weight loss rate, denoted as Q1, and the highest temperature in the range is the temperature at which the thermal weight loss decreases significantly, denoted as Q2; T1 is taken as any value between Q1 and Q2. As for T2, it can be understood as the temperature at which the structure of the activated carbon matrix just begins to collapse, corresponding to the temperature value corresponding to the maximum weight loss rate in the TG curve; the purpose of calcining the modified activated carbon at a temperature greater than T1 and less than T2 is to ensure that the structure of the activated carbon matrix does not collapse, and through calcination, the combined modifier is decomposed to restore the micropore channels of the activated carbon matrix occupied by the modifier. Therefore, the micropore specific surface area S2 of the modified activated carbon after calcination at a temperature greater than T1 and less than T2 can also be understood as: the micropore specific surface area of the activated carbon matrix without the combined modifier. Similarly, S4 can be understood as: the mesopore specific surface area of the activated carbon matrix without the combined modifier.

[0046] Furthermore, in the TG curve of the activated carbon matrix, the temperature range of 2-5 wt% thermal weight loss is denoted as Q3, Q3 < T2. The temperature greater than T1 and less than T2 is denoted as Q4, and Q4 takes any value greater than Q1 and less than or equal to Q3.

[0047] The activated carbon matrix includes a number of micropores and a number of mesopores, and may also include macropores. Since the specific surface area of macropores is relatively low and the supported catalyst can also be ignored, therefore, the macropores of the activated carbon matrix are not specifically limited in the present invention.

[0048] In the present invention, the microporous binding modifier includes a microporous inner surface and / or outer surface binding modifier. The ratio of the microporous specific surface area of ​​the activated carbon to the total specific surface area can be controlled by binding the modifier. In detail, the modified activated carbon is combined with the modifier in the microporous channels of the activated carbon matrix to achieve the occupation of the microporous channels (there may be a small amount of modifier occupying the mesoporous channels). At this time, the microporous specific surface area of ​​the modified activated carbon is S1, and the mesoporous specific surface area is S3. Since the modifier has little effect on the mesoporous channels, when the modified activated carbon is used as a carrier to prepare the catalyst, the active phase will be more attached to the mesoporous channels of the carrier, which is conducive to increasing The probability of larger raw material molecules contacting the active phase is increased, thereby improving the catalytic activity of the catalyst; secondly, since the decomposition temperature T1 of the above-mentioned modifier is lower than the decomposition temperature T2 of the activated carbon, the modified activated carbon can be calcined at a temperature greater than T1 and less than T2 as needed after loading the active group, so that the pore volume of the micropore channels and the small amount of mesopore channels that may be occupied is restored. At this time, the micropore specific surface area of ​​the modified activated carbon is restored to S2, and the mesopore specific surface area is restored to S4. Since S2 and S4 satisfy Equations 2 and 3, the total pore volume and specific surface area of ​​the activated carbon after calcination increase accordingly, thereby realizing precise control of the pore properties of the activated carbon.

[0049] In a preferred embodiment, the modifier is an amino acid. Amino acid modifiers are non-hazardous chemicals, so the modification process has the advantages of being safe and environmentally friendly.

[0050] The above chemical bonds can be understood as being bonded through the interaction between chemical functional groups. As for the type of chemical bonds, the present invention does not impose any particular limitation.

[0051] In a preferred embodiment, the modifier comprises one or more of amidine, benzyl, and thiol functional groups.

[0052] The amidine, benzyl and thiol functional groups can react chemically with the activated carbon matrix to form tightly bound chemical bonds. Water washing will not cause changes in the content of adsorbed organic matter, and can prevent the organic matter from falling off when the modified activated carbon encounters an aqueous solution.

[0053] In a specific embodiment, the modifier is one or more of arginine, phenylalanine, and methionine.

[0054] In a preferred embodiment, the mesoporous specific surface area of ​​the modified activated carbon accounts for more than 50% of the total specific surface area;

[0055] And / or, the micropore specific surface area of ​​the modified activated carbon accounts for less than 50% of the total specific surface area.

[0056] Among them, the mesopore specific surface area accounts for more than 50% of the total specific surface area, which can ensure that the active phase is more attached to the mesoporous channel surface of the carrier, thereby increasing the probability of larger raw material molecules contacting the active phase, and thus improving the catalytic activity of the catalyst; and the micropore specific surface area accounts for less than 50% of the total specific surface area, which can make the active phase less attached to the microporous channel surface of the activated carbon carrier.

[0057] In a preferred embodiment, T2-T1≥50° C. The more significant the difference between T2 and T1 is, the more likely it is that the basic pore structure of the activated carbon matrix will not be destroyed while removing the modifier.

[0058] In a specific embodiment, T1 is selected from any value between 200°C and 400°C.

[0059] In a second aspect, the present invention provides a preparation method as described above, comprising the following steps:

[0060] A mixed system comprising an activated carbon matrix, a modifier and a solvent is stirred at 20-80° C. for 0.5-3 hours, filtered and dried to obtain the product; wherein the pH of the mixed system is 6-10.

[0061] The above method limits the pH of the mixed system to ensure that there is no adverse effect on the basic structure of the activated carbon matrix. If the pH is too high or too low, it may etch the basic skeleton of the micropores and mesopores of the activated carbon matrix, thereby affecting the total specific surface area of ​​the activated carbon matrix.

[0062] In the preparation method provided by the present invention, the present invention does not impose any specific limitation on the solvent of the mixed system, as long as it can play a dispersing role and does not react with the modifier and the activated carbon matrix, for example, deionized water can be used.

[0063] In a third aspect, the present invention provides a catalyst comprising a carrier and an active ingredient supported on the carrier, wherein the carrier is the modified activated carbon described above; the active ingredient is at least partially supported in the mesopores of the modified activated carbon;

[0064] And / or, the active ingredient includes ruthenium trichloride.

[0065] It can be understood that since the micropores of the modified activated carbon are occupied by the modifier, the active ingredients can only be mainly loaded in the mesopores or macropores of the modified activated carbon.

[0066] In a fourth aspect, the present invention provides a catalyst prepared by a method comprising the following steps:

[0067] The active ingredient is loaded into the mesopores of the modified activated carbon through an impregnation treatment to obtain an intermediate; the intermediate is calcined at a temperature greater than T1 and less than T2 to remove the modifier to obtain the catalyst.

[0068] It can be understood that the above method can decompose the modifier of the modified activated carbon, that is, restore the microporous channels occupied by the modifier. Therefore, the characteristics of the above catalyst include: the active ingredients are mainly loaded in the mesoporous channels of the non-microporous channels of the activated carbon matrix.

[0069] In a fifth aspect, the present invention provides a method for catalytic hydrogenation of chemical monomers containing benzene rings, wherein the catalyst comprises any one of the catalysts provided in the third aspect or the fourth aspect.

[0070] In a specific embodiment, the benzene ring-containing chemical monomer is bisphenol A. That is, the present invention also provides a method for preparing hydrogenated bisphenol A by catalytic hydrogenation of bisphenol A, using any one of the catalysts provided in the third aspect or the fourth aspect.

[0071] It can be understood that if the catalyst of the third aspect is used, the method includes: calcining the catalyst at a temperature greater than T1 and less than T2, removing the modifier, and then using it for the catalytic hydrogenation reaction of bisphenol A.

[0072] The present invention will be further described below with reference to specific embodiments:

[0073] There are two types of activated carbon matrices used in the following experiments, both of which are activated carbons provided by Fushun Catalyst Factory. One type of activated carbon has a thermal weight loss temperature of 2.5 wt% at 400°C and is recorded as activated carbon A0; the other type of activated carbon has a thermal weight loss temperature of 2.5 wt% at 450°C and is recorded as activated carbon A01.

[0074] The decomposition temperature of arginine is 250-350°C, the decomposition temperature of methionine is 258-269°C, and the decomposition temperature of phenylalanine is 326-365°C.

[0075] Example 1

[0076] This example provides a modified activated carbon, including an activated carbon matrix, wherein the activated carbon matrix includes a plurality of micropores and a plurality of mesopores, and at least part of the micropores are bound to arginine.

[0077] The preparation method of the modified activated carbon comprises the following steps:

[0078] 10 g of activated carbon matrix A0 was weighed and added to 100 g of deionized water. After stirring evenly, 0.8 g of arginine was added. The pH of the mixed system was 10. After stirring at 45°C for 3 hours, the system was filtered and the solid component was dried at 80-120°C to obtain modified activated carbon A1.

[0079] Example 1-1

[0080] This example provides a catalyst, the preparation method of which comprises the following steps:

[0081] Activated carbon impregnated with ruthenium trichloride was obtained by impregnation and drying using modified activated carbon A1 as the carrier and ruthenium trichloride aqueous solution as the impregnation solution. The activated carbon impregnated with ruthenium trichloride was calcined at 350°C in air for 6 hours to obtain catalyst B1 (ruthenium trichloride content 0.3 wt%).

[0082] Example 2

[0083] This example provides a modified activated carbon, comprising an activated carbon matrix, wherein the activated carbon matrix comprises a plurality of micropores and a plurality of mesopores, and at least a portion of the micropores are bound with arginine and phenylalanine.

[0084] The preparation method of the modified activated carbon comprises the following steps:

[0085] Weigh 10g of activated carbon matrix A0 and add it to 250g of deionized water. Stir thoroughly, then add 0.4g of arginine and 0.2g of phenylalanine. The mixture is kept at a pH of 8. Stir at 20°C for 0.5h, then filter. The solid component is dried to obtain modified activated carbon A2.

[0086] Example 2-1

[0087] This example provides a catalyst, the preparation method of which comprises the following steps:

[0088] Activated carbon impregnated with ruthenium trichloride was obtained by impregnation and drying using a 1.2-fold volume impregnation method with modified activated carbon A2 as the carrier and a ruthenium trichloride aqueous solution as the impregnation solution. The activated carbon impregnated with ruthenium trichloride was calcined at 340°C for 3 hours in an air atmosphere to obtain catalyst B2 (ruthenium trichloride content 0.3 wt%).

[0089] Example 3

[0090] This example provides a modified activated carbon, comprising an activated carbon matrix, wherein the activated carbon matrix comprises a plurality of micropores and a plurality of mesopores, and at least a portion of the micropores are bound with methionine.

[0091] The preparation method of the modified activated carbon comprises the following steps:

[0092] 10g of activated carbon matrix A0 was weighed and added to 100g of deionized water. After stirring, 50g of methionine aqueous solution (containing 0.6g of methionine) was added to the mixture. The pH of the mixture was adjusted to 6. After stirring at 80°C for 2 hours, the mixture was filtered. The solid component was dried to obtain modified activated carbon A3.

[0093] Example 3-1

[0094] This example provides a catalyst, the preparation method of which comprises the following steps:

[0095] Activated carbon impregnated with ruthenium trichloride was obtained by impregnation and drying using a 1.5-fold volume impregnation method, using modified activated carbon A3 as the carrier and a ruthenium trichloride aqueous solution as the impregnation solution. The activated carbon impregnated with ruthenium trichloride was calcined at 280°C in an air atmosphere for 4 hours to obtain catalyst B3 (ruthenium trichloride content 0.3 wt%).

[0096] Example 4

[0097] This example provides a modified activated carbon, comprising an activated carbon matrix, wherein the activated carbon matrix comprises a plurality of micropores and a plurality of mesopores, and at least a portion of the micropores are bound with arginine and methionine.

[0098] The preparation method of the modified activated carbon comprises the following steps:

[0099] 10g of activated carbon matrix A0 was weighed and added to 150g of deionized water. After stirring, 80g of an organic aqueous solution (containing 0.5g of arginine and 0.2g of methionine) was added. The pH of the mixture was adjusted to 8. The mixture was incubated at 30°C with stirring for 2.5 hours and then filtered. The solid component was dried to obtain modified activated carbon A4.

[0100] Example 4-1

[0101] This example provides a catalyst, the preparation method of which comprises the following steps:

[0102] Activated carbon impregnated with ruthenium trichloride was obtained by impregnation and drying using a double-volume impregnation method with modified activated carbon A4 as the carrier and a ruthenium trichloride aqueous solution as the impregnation solution. The activated carbon impregnated with ruthenium trichloride was calcined at 330°C in an air atmosphere for 5 hours to obtain catalyst B4 (ruthenium trichloride content 0.3 wt%).

[0103] Example 5

[0104] This example provides a modified activated carbon, comprising an activated carbon matrix, wherein the activated carbon matrix comprises a plurality of micropores and a plurality of mesopores, and at least a portion of the micropores are bound with arginine and methionine.

[0105] Weigh 10g of activated carbon matrix A01 and add it to 150g of deionized water. Stir thoroughly, then add 80g of an organic aqueous solution (containing 0.5g of arginine and 0.2g of methionine). The mixture is kept at a pH of 8. After stirring at 30°C for 2.5 hours, the mixture is filtered. The solid component is dried to obtain modified activated carbon A5.

[0106] Comparative Example 1

[0107] This example provides a modified activated carbon and a catalyst, the preparation method of which comprises the following steps:

[0108] Weigh 10g of activated carbon matrix into 100g of deionized water, stir thoroughly, and then add 0.6g of arginine. The mixture is kept at a pH of 10. Stir at 45°C for 3 hours, then filter. The solid component is dried to obtain modified activated carbon C1.

[0109] Activated carbon impregnated with ruthenium trichloride was obtained by impregnation and drying using modified activated carbon C1 as the carrier and a ruthenium trichloride aqueous solution as the impregnation solution. The activated carbon impregnated with ruthenium trichloride was calcined at 300°C in air for 6 hours to obtain catalyst D1 (ruthenium trichloride content 0.3 wt%).

[0110] Comparative Example 2

[0111] This example provides a modified activated carbon and a catalyst, the preparation method of which comprises the following steps:

[0112] 10g of activated carbon substrate was mixed with 120mL of water and sonicated for 30 minutes. 30mL of a 1% aqueous glucose solution was added, and the mixture was stirred for 6 hours, filtered, and dried at 110°C for 8 hours. The dried activated carbon was calcined at 800°C for 60 minutes under nitrogen to obtain modified activated carbon C2.

[0113] Activated carbon impregnated with ruthenium trichloride was obtained by impregnation and drying using modified activated carbon C2 as the carrier and ruthenium trichloride aqueous solution as the impregnation solution. The activated carbon impregnated with ruthenium trichloride was calcined at 300°C in air for 6 hours to obtain catalyst D2 (ruthenium trichloride content 0.3 wt%).

[0114] Comparative Example 3

[0115] This example provides a modified activated carbon and a catalyst, the preparation method of which comprises the following steps:

[0116] 6g of glycine was added to 300g of distilled water. After dissolution, 9g of activated carbon matrix was added and mixed evenly. The pH of the mixed system was 6. At a constant temperature of 80°C, high-speed stirring at 100 r / min was performed for 8 hours. The mixture was removed and allowed to stand for 4 hours. After filtering, it was repeatedly washed with distilled water several times until neutral. The modified activated carbon C3 was obtained by drying at 105°C for 12 hours.

[0117] Activated carbon impregnated with ruthenium trichloride was obtained by impregnation and drying using modified activated carbon C3 as a carrier and a ruthenium trichloride aqueous solution as an impregnation solution. The activated carbon impregnated with ruthenium trichloride was calcined at 300°C in an air atmosphere for 6 hours to obtain catalyst D3 (ruthenium trichloride content 0.3 wt%).

[0118] Comparative Example 4

[0119] This example provides a catalyst, the preparation method of which comprises the following steps:

[0120] Activated carbon impregnated with ruthenium trichloride was prepared by impregnation and drying using activated carbon A0 as the carrier and a ruthenium trichloride aqueous solution as the impregnation solution. The activated carbon impregnated with ruthenium trichloride was calcined at 300°C in air for 6 hours to obtain catalyst D4 (ruthenium trichloride content 0.3 wt%).

[0121] Test Example 1

[0122] UV-visible spectroscopy was used to characterize the success of activated carbon modification and the ability of the modified activated carbon to maintain its organic matter content after washing. Figure 1 As shown, in the initial stage of preparation, 0.8 g of arginine was dissolved in 100 g of water and there was an obvious UV-visible absorption spectrum; 10 g of activated carbon matrix was added under stirring, and after constant stirring at 45 ° C for 3 h, the absorbance of the UV-visible absorption spectrum of the aqueous solution decreased significantly, indicating that the arginine in the solution had been combined with the activated carbon matrix to form a modified activated carbon A1 successfully modified with arginine, and then the modified activated carbon A1 was added to 100 g of water, stirred and washed, and the washed solution was filtered. The UV-visible absorption spectrum showed that it did not have a significant absorption spectrum, further indicating that arginine had reacted chemically with the activated carbon to form a stable arginine-activated carbon structure. Thus, the modified activated carbon A1 can be used for subsequent load modification treatment in an aqueous solution environment; the modified activated carbons of other embodiments were subjected to the same test, and the washed solution did not show a significant absorption spectrum in the UV-visible absorption spectrum. The results show that the agent of each embodiment can be stably combined with the activated carbon through chemical bonds and can be used for subsequent load modification treatment in an aqueous solution environment.

[0123] Thermogravimetric characterization was performed under air atmosphere at a temperature higher than the decomposition temperature of the modified organic matter and lower than the temperature at which the activated carbon loses significant weight. It was proved that the modifier can be removed by calcination: Activated carbon A0 and modified activated carbon A1 were subjected to thermogravimetric characterization under air atmosphere. The characterization conditions were air atmosphere, heat treatment temperature was 120℃~500℃, and the Figure 2 Activated carbon A0 exhibited a 2.5% weight loss at 400°C, while modified activated carbon A1 exhibited significant weight loss compared to A0 starting at 200°C, indicating that the modifier, arginine, can gradually decompose in air at temperatures between 200°C and 400°C. This demonstrates that calcining in air at a temperature above the decomposition temperature of the modified organic matter but below the temperature at which the activated carbon experiences significant weight loss can remove organic components from organic-modified activated carbon, thereby restoring the activated carbon's micropores that were clogged during the modification process.

[0124] Test Example 2

[0125] Modified activated carbons A1-A5, C1, and C3 were calcined at 350°C for 6 h in air to obtain activated carbons A1'-A5', C1', and C3'. Activated carbons A0, A1-A5, A1'-A5', C1, C2, C3, C1', and C3' were characterized by nitrogen physical adsorption. The characterization results are shown in Table 1. The total specific surface area was calculated using the BET method. To ensure the validity of the BET equation, the BET specific surface area was calculated by selecting at least three points within the p / p0 range of 0.01 to 0.30, satisfying the condition that the C value of the BET equation was greater than 0. The mesoporous and microporous specific surface areas were calculated using the t-Plot method.

[0126] Table 1 Physical adsorption characterization results of activated carbon

[0127]

[0128] From the data in Table 1, we can see that the micropore specific surface area of ​​A1, A2, A3, and A4 is significantly reduced compared with A0. Specifically, the micropore specific surface area of ​​A0 accounts for 60% of the total specific surface area, and the micropore specific surface area of ​​A1, A2, A3, and A4 accounts for 45% to 48% of the total specific surface area. The micropore specific surface area of ​​A5 is also significantly reduced compared with A01. Specifically, the micropore specific surface area of ​​A01 accounts for 92% of the total specific surface area, and the micropore specific surface area of ​​A5 accounts for 45% of the total specific surface area. Although the micropore specific surface area of ​​C1 is reduced due to insufficient addition of the modifier, the micropore specific surface area of ​​C1 accounts for 58% of the total specific surface area, which is not much different from A0. C2 uses sugar as a modifier. Sugar substances have the characteristic of volume expansion when heat-treated in an inert atmosphere. Therefore, C2 has a significant reduction in both micropore and mesopore specific surface areas. C3 is an activated carbon treated with glycine. Since glycine cannot chemically bond with activated carbon, it is carried away by water during washing and does not successfully occupy the micropores of the activated carbon. Its total specific surface area and micropore specific surface area do not change much. The above results show that the modified activated carbons of each embodiment of the present invention can better occupy the micropores of the activated carbon, significantly reduce the micropore specific surface area, and have no significant effect on the mesopore specific surface area, which is more conducive to the attachment of active metals to the mesopores of the activated carbon during the impregnation process. Moreover, by comparing modified activated carbons A1-A4 with A1'-A4', A5 and A5', it can be seen that the micropore specific surface area of ​​the modified activated carbons of each embodiment of the present invention can be well restored by heat treatment, indicating that the modified activated carbon of the present invention can be used as a carrier to allow the active phase to attach to the mesopore channels and then restore its original micropore channels by heat treatment.

[0129] Test Example 2

[0130] Catalysts B1, B2, B3, B4, D1, D2, D3, and D4 were pre-reduced in a tube furnace at 120°C for 2 hours. The catalytic activity of each catalyst in the catalytic hydrogenation of bisphenol A to produce hydrogenated bisphenol A was then evaluated in a tank reactor. The specific evaluation conditions were: a 20% bisphenol A solution prepared in isopropyl alcohol, a 2% catalyst dosage, a reaction temperature of 170°C, a pressure of 4.0 MPa, and a reaction time of 4 hours. The conversion of bisphenol A under these conditions was evaluated, and the evaluation results are shown in Table 2.

[0131] Table 2 Evaluation results

[0132]

[0133]

[0134] As can be seen from the data in Table 2, the catalyst prepared by the present invention can be used for the catalytic hydrogenation of bisphenol A to prepare hydrogenated bisphenol A, which can further improve the conversion rate of bisphenol A. This means that the use of the catalyst of the present invention is more conducive to the hydrogenation saturation process of molecules such as bisphenol A, which are difficult to enter the microporous structure due to their relatively large molecular size.

[0135] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A modified activated carbon, characterized in that It includes an activated carbon matrix, and the activated carbon matrix includes a number of micropores and a number of mesopores. Among them, at least part of the micropores are chemically bonded with a modifier; and the modified activated carbon satisfies the following formulas 1 to 3: T1 < T2 Formula 1, 0.4 ≤ S1 / S2 ≤ 0.6 Formula 2, 0.8 ≤ S3 / S4 ≤ 1 Formula 3; Where, T1 is the decomposition temperature of the modifier, T2 is the initial decomposition temperature of the activated carbon matrix, S1 is the micropore specific surface area of the modified activated carbon, S2 is the micropore specific surface area of the modified activated carbon after calcination at a temperature greater than T1 and less than T2, S3 is the mesopore specific surface area of the modified activated carbon, and S4 is the mesopore specific surface area of the modified activated carbon after calcination at a temperature greater than T1 and less than T2.

2. The modified activated carbon according to claim 1, characterized in that The modifier is an amino acid; and / or, the modifier contains one or more of amidino, benzyl, and mercapto functional groups.

3. The modified activated carbon according to claim 2, characterized in that The modifier is one or more of arginine, phenylalanine, and methionine.

4. The modified activated carbon according to any one of claims 1 to 3, characterized in that The mesopore specific surface area of the modified activated carbon accounts for more than 50% of the total specific surface area; and / or, the micropore specific surface area of the modified activated carbon accounts for less than 50% of the total specific surface area.

5. The modified activated carbon according to any one of claims 1 to 3, characterized in that T2 - T1 ≥ 50°C.

6. A method for preparing modified activated carbon according to any one of claims 1 to 5, characterized in that: It includes the following steps: A mixed system containing an activated carbon matrix, a modifier, and a solvent is stirred at 20 - 80°C for 0.5 - 3 h, and then obtained by filtration and drying; where the pH of the mixed system is 6 - 10.

7. A catalyst comprising a carrier and an active ingredient supported on the carrier, characterized in that: The carrier is the modified activated carbon according to any one of claims 1 - 5; at least part of the active ingredient is loaded in the mesopores of the modified activated carbon; and / or, the active ingredient includes ruthenium trichloride.

8. A catalyst, characterized in that It is prepared by a method including the following process: Through impregnation treatment, the active ingredient is loaded in the mesopores of the modified activated carbon according to any one of claims 1 - 5 to obtain an intermediate; the intermediate is calcined at a temperature greater than T1 and less than T2 to remove the modifier, and the catalyst is obtained.

9. A method for catalytic hydrogenation of chemical monomers containing benzene rings, characterized in that: The catalyst includes the catalyst according to any one of claims 7 - 8.

10. The catalytic hydrogenation method according to claim 9, characterized in that: The chemical monomer containing a benzene ring is bisphenol A.

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