CN113426474B

CN113426474B - Boric acid modified iron-zirconium shape-selective catalyst and preparation method and application thereof

Info

Publication number: CN113426474B
Application number: CN202110586814.8A
Authority: CN
Inventors: 戴立言; 蔡梦露; 王晓钟; 陈英奇
Original assignee: Quzhou Research Institute of Zhejiang University
Current assignee: Quzhou Research Institute of Zhejiang University
Priority date: 2021-05-27
Filing date: 2021-05-27
Publication date: 2022-05-03
Anticipated expiration: 2041-05-27
Also published as: CN113426474A

Abstract

The invention relates to the field of alkyl anthracene compounds, in particular to a boric acid modified iron-zirconium shape-selective catalyst and a preparation method and application thereof. The catalyst comprises a carrier and metal/nonmetal elements loaded on the carrier, wherein the metal elements comprise iron and zirconium which are pre-selected and treated by citric acid, and the weight ratio of the iron to the zirconium is 0.05-0.4: 1 in terms of oxides; the non-metal element is boric acid, and the modification concentration of the boric acid is 0.5-1.5 mol/L. According to the invention, boric acid is used as a boron oxide precursor, and boron oxide is uniformly loaded on the surface of the high-dispersion iron-zirconium loaded catalyst obtained by citric acid treatment in a backflow and calcination mode. The catalyst obtained by the invention has good shape-selective catalytic effect on 2-tert-amyl anthracene generated by alkylation of anthracene, is simple in preparation method, stable in catalytic performance under mild conditions, and recyclable, and therefore, has significant industrial application value.

Description

Boric acid modified iron-zirconium shape-selective catalyst and preparation method and application thereof

Technical Field

The invention relates to the field of alkyl anthracene compounds, in particular to a boric acid modified iron-zirconium shape-selective catalyst, a preparation method thereof and application thereof in high-selectivity synthesis of 2-alkyl anthracene in anthryl.

Background

2-alkyl anthracene is an important organic chemical intermediate, and the oxidation product 2-alkyl anthraquinone of the 2-alkyl anthracene can obviously influence the quality and the yield of the green basic chemical hydrogen peroxide as a carrier of the production process. The phthalic anhydride method is the main method for producing the pentanthraquinone at present, but a large amount of aluminum trichloride and fuming sulfuric acid are used, and the environment is seriously polluted. The method is characterized in that anthracene and a corresponding alkylating reagent are alkylated and then oxidized to obtain 2-alkyl anthracene, which is an economical production line of 2-alkyl anthraquinone at present, and the research on a catalyst in an alkylation process and an oxidation process is necessary aiming at the green production process, but the process has the problems of low alkylation conversion rate and selectivity at present, and the subsequent oxidation process is seriously influenced so as to influence the quality of the 2-alkyl anthraquinone.

In particular, in the case of heterogeneous catalytic alkylation, the conversion/selectivity is closely related to the number of acid sites on the surface of the catalyst and the type of acid (Korean Journal of Chemical Engineering,2009,26,1563-1567), and in particular, in the case of heterogeneous catalytic alkylation, the catalyst activity and stability are poor, the conversion rate of the reaction is low due to difficult activation of the substrate, and the selectivity of the target reaction is low due to easy formation of multi-substituted alkylation products. Armengol E group has conducted extensive studies on tert-butanol alkylation of naphthalene, anthracene, thiophene and the like, and has proposed a corresponding alkylation mechanism. Zeolite molecular sieves were used as catalysts in the study, and finally Y zeolite was found to be the most active catalyst in this type of reaction. HY molecular sieve has much higher catalytic efficiency as catalyst than toluene sulfonic acid in the same reaction of anthracene and tert-butyl alcohol to prepare alkyl anthracene (Applied Catalysis A General,1997,149, 411-423). In addition, the metal modification can improve the overall activity of the catalyst, and can adjust the conversion rate and selectivity according to the reaction requirement, and studies on the reaction of benzene and isoamylene catalyzed by the lanthanum-modified H beta molecular sieve in 2015 and the like, wherein the conversion rate reaches 98.9 percent, and the content of tert-amylbenzene is 78.6 percent (chemical and biological engineering, 2015, 39-42). In addition, the oxide modification can cover the acid sites on the surface of the molecular sieve, and oxide precursors can be dispersed on the outer surface of the catalyst during the impregnation process, so that the shape-selective catalyst can be prepared by improving the preparation mode although the phenomenon of partially blocking the pore channels exists. Patents on boron oxide preparation of shape-selective catalysts have been reported (CN103394365A, CN104084233A), and in addition, in 2017 schroe et al prepared boric acid modified MCM-22 molecular sieve by impregnation method, the catalysts also have excellent para-selectivity and higher catalytic activity in the alkylation reaction of toluene and dimethyl carbonate (chemical development, 2017,36,2177-. The alkylation reaction of anthracene is often accompanied by the generation of disubstituted and other position substitution products, so that it is necessary to develop a shape-selective catalyst for synthesizing 2-alkyl anthracene and having high selectivity to 2-alkyl anthracene.

Disclosure of Invention

The invention aims to solve the problems of low selectivity of 2-alkyl anthracene, high specific gravity of disubstituted alkyl anthracene, serious equipment corrosion and the like in the process of anthrylation in the prior art, and provides a preparation method and application of a boric acid modified iron-zirconium shape-selective catalyst.

The invention provides a boric acid modified iron-zirconium shape-selective catalyst, which comprises a carrier and metal/nonmetal elements loaded on the carrier, wherein the metal elements comprise iron and zirconium which are pre-selected and treated by citric acid, and the weight ratio of the iron to the zirconium is 0.05-0.4: 1 in terms of oxides; the non-metal element is boric acid, and the modification concentration of the boric acid is 0.5-1.5 mol/L.

According to a preferred embodiment of the invention, the weight ratio of iron, zirconium and boron, calculated as oxides, is (0.17-0.67): (1-2): (2.1-7). Under the preferential implementation, the catalyst has better catalytic performance, various oxides are uniformly distributed, and the uniform dispersion of the boron oxide has a promoting effect on the alkylation reaction catalyzed by acid. The inventor of the invention finds that under the preferred embodiment, the dispersion of the iron-zirconium metal element in the boric acid modified catalyst is not obviously influenced, the surface of the boric acid modified catalyst has defects, the shape-selective effect of the alkylation reaction is ensured, the catalytic activity of the catalyst is improved, and the synergistic effect of bimetal enables the whole catalyst to have stronger acidity, so that the catalyst has a promoting effect on the acid-catalyzed alkylation reaction.

The content of each component in the boric acid modified iron-zirconium shape-selective catalyst is selected widely, and preferably, relative to 100 parts by weight of the carrier, the total content of iron and zirconium is 11-44 parts by weight, preferably 11-21 parts by weight, calculated by oxide, and the content of boric acid is 21-130 parts by weight, preferably 21-54 parts by weight, calculated by oxide.

In the present invention, when the catalyst contains only the carrier and the metal element in the active component contains only iron and zirconium, the sum of the content of the carrier in the catalyst, the content of iron in terms of oxide, the content of zirconium in terms of oxide and the content of boron in terms of oxide is 100% by weight based on the total amount of the catalyst.

The composition of the carrier in the catalyst can be conventional in the field, the carrier is preferably a molecular sieve, and the molecular sieve is at least one of MOR molecular sieve, MCM-22, MCM-41, total silicon beta molecular sieve and SBA-15, and can be selected from commercial products or prepared by the existing method.

According to a preferred embodiment of the invention, the catalyst consists of FeZr-MOR obtained by a previous treatment with boric acid and citric acid.

The second aspect of the invention provides a preparation method of a boric acid modified iron-zirconium shape-selective catalyst, which comprises the following steps:

(1) adding boric acid into deionized water, stirring until the boric acid is completely dissolved, then adding an iron-zirconium supported catalyst, and carrying out reflux exchange for 4 hours at 80 ℃;

(2) and (2) filtering and washing the substance obtained in the step (1), drying at 100 ℃, grinding, calcining at 500 ℃ in an air atmosphere, and annealing to obtain the boric acid modified iron-zirconium shape-selective catalyst.

The using amounts of the zirconium salt and the precursor of the iron are used in the iron-zirconium supported catalyst, and the weight ratio of the iron to the zirconium is 0.05-0.4: 1 in terms of oxide; the calcination time is 4-10 h.

In the boric acid modified iron-zirconium shape selective catalyst, relative to 100 parts by weight of the carrier, the total content of iron and zirconium is 11-44 parts by weight, preferably 11-21 parts by weight in terms of oxide, and the content of boric acid in terms of oxide is 21-130 parts by weight, preferably 21-54 parts by weight.

The preparation process of the iron-zirconium supported catalyst is carried out by treating with citric acid, adding citric acid to improve the whole acidity of the catalyst, forming metal compound with metal salt, in-situ decomposing during drying, and calcining to obtain the final product. And the subsequent surface dispersion of boric acid is facilitated, so that the boric oxide uniformly covers the surface acid sites and protects the internal pore acid sites. By the preparation method, the agglomeration of oxides can be reduced, so that the activity and selectivity of the catalyst are ensured, and meanwhile, the overall acidity of the catalyst is stronger due to the synergistic effect of the Fe-Zr double metals, so that the catalyst has a promotion effect on the acid-catalyzed alkylation reaction.

The selection range of the zirconium salt is wide, and preferably, the zirconium salt is at least one of zirconium nitrate pentahydrate, zirconium oxychloride and zirconium acetate.

The selection range of the precursor of the iron is wide, and preferably, the precursor of the iron is at least one of ferric nitrate nonahydrate and ferric chloride hexahydrate.

According to the third aspect of the invention, the boric acid modified iron-zirconium shape-selective catalyst prepared by the method is stable in catalytic performance and higher in selectivity on alkylation reaction products. Meanwhile, the overall acidity of the catalyst is enhanced due to the synergistic effect of bimetal, so that the catalyst has a promotion effect on the acid-catalyzed alkylation reaction, the reaction condition is mild in the process of catalyzing the alkylation anthracene to generate the 2-tert-amyl anthracene, the selectivity of the product 2-tert-amyl anthracene is relatively high, and the catalyst has a remarkable industrial application value.

Through the technical scheme, the boric acid modified iron-zirconium shape-selective catalyst is a heterogeneous catalyst, is simple and convenient in preparation method and easy to recover and recycle, and the overall acidity is improved due to citric acid treatment and boric acid modification. The high-dispersion active component obtained by pretreating citric acid ensures that the alkylation catalytic activity and selectivity are high, the catalytic performance is more stable, the subsequent surface dispersion of boric acid reflux modification is facilitated, the surface acid sites are uniformly covered after calcination, and the internal pore acid sites are protected. Compared with the modification mode by a boric acid dipping method, the mode of uniformly dispersing the metal active sites and then carrying out boric acid reflux modification reduces the agglomeration of metal oxides and the defects on the surface of the prepared catalyst, thereby ensuring the activity and the selectivity of the catalyst. Under the preferable condition, the boric acid modified iron-zirconium shape selective catalyst provided by the invention adopts an MOR molecular sieve as a carrier, has higher selectivity on 2-tert-amyl anthracene, and is particularly suitable for the reaction for preparing 2-alkyl anthracene by taking anthracene as a raw material.

The invention relates to the field of preparation of 2-alkyl anthracene, and discloses a boric acid modified iron-zirconium shape-selective catalyst, and a preparation method and application thereof. Wherein the weight ratio of iron, zirconium and boron (0.17-0.67) calculated by oxide: (1-2): (2.1-13). The catalyst obtained by the invention has good shape-selective catalytic effect on 2-tert-amyl anthracene generated by alkylation of anthracene, is simple in preparation method, stable in catalytic performance under mild conditions, and recyclable, and therefore, has significant industrial application value.

Drawings

Fig. 1 is SEM images of the boric acid-modified iron zirconium shape-selective catalyst (a), the partial magnification (b) and the non-boric acid-modified iron zirconium catalyst (c) in comparative example 1 obtained in specific example 1 of the present invention.

Detailed Description

The present invention will be described in detail below by way of examples. However, the present invention is not limited to these embodiments, and various simple modifications and other combinations of the features of the present invention should be considered as the disclosure of the present invention, and all the combinations fall within the scope of the present invention.

Unless otherwise stated, room temperature is indicated as 25 ℃.

Example 1

First step catalyst preparation: 4.12g of zirconium nitrate pentahydrate, 2.22g of citric acid were added to 60mL of deionized water at room temperature, stirred, and then 4g of MOR molecular sieve was added. Stirring for 2h, evaporating water at 80 ℃, drying for 24h at 100 ℃, grinding, and calcining for 10h at 500 ℃ to prepare the citric acid modified 22 wt% Zr-MOR (S1-0) molecular sieve catalyst. 202mg of ferric nitrate nonahydrate and 115mg of citric acid were added to 30mL of deionized water at room temperature, stirred, and then 2g was added (S1-0), and stirring was continued for 2 hours, and then water was evaporated at 80 ℃, dried at 100 ℃ for 24 hours, ground, and calcined at 500 ℃ for 10 hours, to prepare a citric acid-treated iron-zirconium supported catalyst (S1). Adding 1.85g of boric acid into 30mL of deionized water at room temperature to prepare a 1.0mol/L boric acid solution, stirring until the boric acid solution is completely dissolved, then adding 1.2g of the iron-zirconium supported catalyst S1 obtained in the first step, heating to 80 ℃, carrying out reflux exchange for 4h, cooling to room temperature, filtering, washing, drying at 100 ℃, grinding, calcining at 500 ℃ for 4h in an air atmosphere, and annealing to obtain the boric acid modified iron-zirconium shape selective catalyst, which is recorded as Cat 1.

The second step of catalytic alkylation reaction: taking the Cat1 catalyst (39 wt%, 0.39g) and anthracene (1.0g) obtained in the first step, adding 8mL mesitylene as a solvent, adding tert-amyl alcohol (1.1eq,0.55g) as an alkylating reagent, stirring at room temperature, fully mixing and activating, starting pressurizing to 3.0MPa, then carrying out temperature programming to 180 ℃ for reaction, wherein the total reaction time is 4 h. The selectivity of 2-tert-amylanthracene was 91.4% by gas phase analysis, and the yield was 43.7%.

Comparative example 1

Taking an iron-zirconium supported catalyst S1(39 wt%, 0.39g) which is not modified by boric acid and anthracene (1.0g), adding 8mL of mesitylene as a solvent, adding tert-amyl alcohol (1.1eq,0.55g) as an alkylating reagent, stirring at room temperature, fully mixing and activating, starting pressurizing to 3.0MPa, and then carrying out temperature programming to 180 ℃ for reaction, wherein the total reaction time is 4 h. The selectivity of 2-tert-amylanthracene was 92.7% by gas phase analysis, with a yield of 32.0%.

Example 2

First step catalyst preparation: a citric acid-treated iron-zirconium supported catalyst was prepared according to the method of example 1 (S1). Adding 0.93g of boric acid into 30mL of deionized water at room temperature to prepare a 0.5mol/L boric acid solution, stirring until the boric acid solution is completely dissolved, then adding 1.2g of the iron-zirconium supported catalyst S1 obtained in the first step, heating to 80 ℃, carrying out reflux exchange for 4h, cooling to room temperature, filtering, washing, drying at 100 ℃, grinding, calcining at 500 ℃ for 4h in an air atmosphere, and annealing to obtain the boric acid modified iron-zirconium shape selective catalyst, which is recorded as Cat 2.

The second step of catalytic alkylation reaction: taking the Cat2 catalyst (39 wt%, 0.39g) and anthracene (1.0g) obtained in the first step, adding 8mL mesitylene as a solvent, adding tert-amyl alcohol (1.1eq,0.55g) as an alkylating reagent, stirring at room temperature, fully mixing and activating, starting pressurizing to 3.0MPa, then carrying out temperature programming to 180 ℃ for reaction, wherein the total reaction time is 4 h. The selectivity of 2-tert-amylanthracene was 88.2% by gas phase analysis, and the yield was 44.8%.

Example 3

First step catalyst preparation: a citric acid-treated iron-zirconium supported catalyst was prepared according to the method of example 1 (S1). Adding 1.39g of boric acid into 30mL of deionized water at room temperature to prepare a 0.75mol/L boric acid solution, stirring until the boric acid solution is completely dissolved, then adding 1.2g of the iron-zirconium supported catalyst S1 obtained in the first step, heating to 80 ℃, carrying out reflux exchange for 4h, cooling to room temperature, filtering, washing, drying at 100 ℃, grinding, calcining at 500 ℃ for 4h in an air atmosphere, and annealing to obtain the boric acid modified iron-zirconium shape selective catalyst, which is recorded as Cat 3.

The second step of catalytic alkylation reaction: taking the Cat3 catalyst (39 wt%, 0.39g) and anthracene (1.0g) obtained in the first step, adding 8mL mesitylene as a solvent, adding tert-amyl alcohol (1.1eq,0.55g) as an alkylating reagent, stirring at room temperature, fully mixing and activating, starting pressurizing to 3.0MPa, then carrying out temperature programming to 180 ℃ for reaction, wherein the total reaction time is 4 h. The selectivity of 2-tert-amylanthracene was 88.7% by gas phase analysis, and the yield was 49.0%.

Example 4

First step catalyst preparation: a citric acid-treated iron-zirconium supported catalyst was prepared according to the method of example 1 (S1). Adding 2.32g of boric acid into 30mL of deionized water at room temperature to prepare a 1.25mol/L boric acid solution, stirring until the boric acid solution is completely dissolved, then adding 1.2g of the iron-zirconium supported catalyst S1 obtained in the first step, heating to 80 ℃, carrying out reflux exchange for 4h, cooling to room temperature, filtering, washing, drying at 100 ℃, grinding, calcining at 500 ℃ for 4h in an air atmosphere, and annealing to obtain the boric acid modified iron-zirconium shape selective catalyst, which is recorded as Cat 4.

The second step of catalytic alkylation reaction: taking the Cat4 catalyst (39 wt%, 0.39g) and anthracene (1.0g) obtained in the first step, adding 8mL mesitylene as a solvent, adding tert-amyl alcohol (1.1eq,0.55g) as an alkylating reagent, stirring at room temperature, fully mixing and activating, starting pressurizing to 3.0MPa, then carrying out temperature programming to 180 ℃ for reaction, wherein the total reaction time is 4 h. The selectivity of 2-tert-amylanthracene was 92.0% by gas phase analysis, and the yield was 37.5%.

Example 5

First step catalyst preparation: a citric acid-treated iron-zirconium supported catalyst was prepared according to the method of example 1 (S1). Adding 2.78g of boric acid into 30mL of deionized water at room temperature to prepare a 1.5mol/L boric acid solution, stirring until the boric acid solution is completely dissolved, then adding 1.2g of the iron-zirconium supported catalyst S1 obtained in the first step, heating to 80 ℃, carrying out reflux exchange for 4h, cooling to room temperature, filtering, washing, drying at 100 ℃, grinding, calcining at 500 ℃ for 4h in an air atmosphere, and annealing to obtain the boric acid modified iron-zirconium shape selective catalyst, which is recorded as Cat 5.

The second step of catalytic alkylation reaction: taking the Cat5 catalyst (39 wt%, 0.39g) and anthracene (1.0g) obtained in the first step, adding 8mL mesitylene as a solvent, adding tert-amyl alcohol (1.1eq,0.55g) as an alkylating reagent, stirring at room temperature, fully mixing and activating, starting pressurizing to 3.0MPa, then carrying out temperature programming to 180 ℃ for reaction, wherein the total reaction time is 4 h. The gas phase analysis showed that the selectivity for 2-tert-amylanthracene was 99.99% with a yield of 7.8%.

Example 6

First step catalyst preparation: 808mg of ferric nitrate nonahydrate and 460mg of citric acid were added to 60mL of deionized water at room temperature, stirred, and then 4g was added (S1-0), and stirring was continued for 2 hours, and then water was evaporated at 80 ℃, dried at 100 ℃ for 24 hours, ground, and calcined at 500 ℃ for 10 hours, to prepare a citric acid-treated iron-zirconium supported catalyst (S2). Adding 1.23g of boric acid into 20mL of deionized water at room temperature to prepare a 1.0mol/L boric acid solution, stirring until the boric acid solution is completely dissolved, then adding 1.2g of the iron-zirconium supported catalyst S2 obtained in the first step, heating to 80 ℃, carrying out reflux exchange for 4h, cooling to room temperature, filtering, washing, drying at 100 ℃, grinding, calcining at 500 ℃ for 4h in an air atmosphere, and annealing to obtain the boric acid modified iron-zirconium shape selective catalyst, which is recorded as Cat 6.

The second step of catalytic alkylation reaction: taking the Cat6 catalyst (39 wt%, 0.39g) and anthracene (1.0g) obtained in the first step, adding 8mL mesitylene as a solvent, adding tert-amyl alcohol (1.1eq,0.55g) as an alkylating reagent, stirring at room temperature, fully mixing and activating, starting pressurizing to 3.0MPa, then carrying out temperature programming to 180 ℃ for reaction, wherein the total reaction time is 4 h. The selectivity of 2-tert-amylanthracene was 91.3% by gas phase analysis, and the yield was 37.6%.

Example 7

First step catalyst preparation: 101mg of ferric nitrate nonahydrate and 60mg of citric acid are added into 30mL of deionized water at room temperature, stirred, then 2g is added (S1-0), stirring is continued for 2h, then water is evaporated at 80 ℃, dried for 24h at 100 ℃, ground and calcined for 10h at 500 ℃ to prepare the citric acid treated iron-zirconium supported catalyst (S3). Adding 1.85g of boric acid into 30mL of deionized water at room temperature to prepare a 1.0mol/L boric acid solution, stirring until the boric acid solution is completely dissolved, then adding 1.2g of the iron-zirconium supported catalyst S1 obtained in the first step, heating to 80 ℃, carrying out reflux exchange for 4h, cooling to room temperature, filtering, washing, drying at 100 ℃, grinding, calcining at 500 ℃ for 4h in an air atmosphere, and annealing to obtain the boric acid modified iron-zirconium shape selective catalyst, which is recorded as Cat 7.

The second step of catalytic alkylation reaction: taking the Cat7 catalyst (30 wt%, 0.30g) and anthracene (1.0g) obtained in the first step, adding 8mL mesitylene as a solvent, adding tert-amyl alcohol (1.1eq,0.55g) as an alkylating reagent, stirring at room temperature, fully mixing and activating, starting pressurizing to 3.0MPa, then carrying out temperature programming to 180 ℃ for reaction, wherein the total reaction time is 4 h. The selectivity of 2-tert-amylanthracene was 95.1% by gas phase analysis, and the yield was 28.2%.

Example 8

The Cat1 catalyst (30 wt%, 0.30g) and anthracene (1.0g) obtained in example 1 were taken, 8mL of 3, 4-dichlorotrifluorotoluene was added as a solvent, t-amyl alcohol (1.1eq,0.55g) was added as an alkylating agent, and the mixture was stirred at room temperature for sufficient mixing and activation, initial pressure was increased to 3.0MPa, and then temperature was programmed to 180 ℃ for reaction for a total reaction time of 4 hours. The gas phase analysis showed that the selectivity to 2-tert-amylanthracene was 99.90% and the yield was 10.2%.

Example 9

The Cat1 catalyst (30 wt%, 0.30g) and anthracene (1.0g) obtained in example 1 were taken, 8mL of 3, 4-cyclohexane was added as a solvent, t-amyl alcohol (1.1eq,0.55g) was added as an alkylating agent, and the mixture was stirred at room temperature for sufficient mixing and activation, initially charged to 3.0MPa, and then temperature programmed to 180 ℃ for reaction for a total reaction time of 4 h. The selectivity of 2-tert-amylanthracene was 98.3% by gas phase analysis, and the yield was 16.0%.

Example 10

The Cat1 catalyst (15 wt%, 0.15g) and anthracene (1.0g) obtained in example 1 were taken, 8mL mesitylene was added as a solvent, t-amyl alcohol (2.0eq,1.10g) was added as an alkylating agent, the mixture was stirred at room temperature and fully mixed for activation, initial pressurization was carried out to 2.0MPa, and then temperature programming was carried out to 160 ℃ for reaction, and the total reaction time was 8 h. The selectivity of 2-tert-amylanthracene was 99.9% by gas phase analysis, and the yield was 5.2%.

Example 11

The Cat1 catalyst (20 wt%, 0.20g) and anthracene (1.0g) obtained in example 1 were taken, 8mL mesitylene was added as a solvent, t-amyl alcohol (1.5eq,0.74g) was added as an alkylating agent, stirring was carried out at room temperature, mixing and activating were carried out thoroughly, initial pressurization was carried out to 1.0MPa, and then temperature programming was carried out to 170 ℃ for reaction, and the total reaction time was 6 h. The selectivity of 2-tert-amylanthracene was 99.9% by gas phase analysis, and the yield was 8.6%.

Example 12

First step catalyst preparation: a citric acid-treated iron-zirconium supported catalyst was prepared according to the method of example 1 (S1). Adding 1.85g of boric acid into 30mL of deionized water at room temperature to prepare a 1.0mol/L boric acid solution, stirring until the boric acid solution is completely dissolved, then adding 1.2g of the iron-zirconium supported catalyst S1 obtained in the first step, heating to 80 ℃, carrying out reflux exchange for 4h, cooling to room temperature, filtering, washing, drying at 100 ℃, grinding, calcining at 500 ℃ for 10h in an air atmosphere, and annealing to obtain the boric acid modified iron-zirconium shape selective catalyst, which is recorded as Cat 8.

The second step of catalytic alkylation reaction: taking the Cat8 catalyst (39 wt%, 0.78g) and anthracene (2.0g) obtained in the first step, adding 16mL mesitylene as a solvent, adding tert-amyl alcohol (1.1eq,1.09g) as an alkylating reagent, stirring at room temperature, fully mixing and activating, starting pressurizing to 3.0MPa, then carrying out temperature programming to 180 ℃ for reaction, wherein the total reaction time is 4 h. The selectivity of 2-tert-amylanthracene was 90.0% by gas phase analysis, and the yield was 39.4%.

Example 13

The method of example 1 is adopted, the Cat1 catalyst obtained in example 1 is applied to the reaction of preparing 2-tert-amyl anthracene by alkylating anthracene and tert-amyl alcohol, the catalyst is recovered after the reaction, the process of test example 1 is repeated on the obtained catalyst, and the selectivity and the yield of the 2-amyl anthracene are simultaneously measured. The results are shown in Table 1.

TABLE 1

Number of tests	Selectivity/%)	Yield/%
			1	91.4	43.7
2	93.1	44.6
			3	93.5	37.7
4	90.0	35.5

From the results in table 1, it can be seen that the boric acid modified iron-zirconium shape-selective catalyst prepared by the method of the present invention has high shape-selective performance for the alkylation process of anthracene, and in addition, the boric acid modified iron-zirconium shape-selective catalyst can be recycled after being recycled, and still has high selectivity after being repeated for multiple times.

Claims

1. A boric acid modified iron-zirconium shape-selective catalyst is characterized by comprising a carrier and metal and nonmetal components loaded on the carrier, wherein the metal components are subjected to citric acid treatment in advance;

the metal component comprises iron and zirconium, and the weight ratio of the iron to the zirconium is 0.05-0.4: 1 in terms of oxides; the total content of iron and zirconium is 11 to 44 parts by weight in terms of oxide with respect to 100 parts by weight of the carrier;

the non-metal component is boric acid, and the modification concentration of the boric acid is 0.5-1.5 mol/L;

the carrier is a molecular sieve selected from at least one of MOR molecular sieve, MCM-22, MCM-41, full silicon beta molecular sieve and SBA-15;

the preparation method comprises the following steps:

(2) filtering and washing the substance obtained in the step (1), drying at 100 ℃, grinding, calcining at 500 ℃ in an air atmosphere, and annealing to obtain a boric acid modified iron-zirconium shape-selective catalyst;

the iron-zirconium supported catalyst is obtained by calcining in the form of citric acid compound.

2. The preparation method of the boric acid modified iron-zirconium shape-selective catalyst in claim 1, which is characterized by comprising the following steps:

(2) filtering and washing the substance obtained in the step (1), drying at 100 ℃, grinding, calcining at 500 ℃ in the air atmosphere, and annealing to obtain the boric acid modified iron-zirconium shape-selective catalyst;

3. The preparation method of the boric acid modified iron-zirconium shape-selective catalyst according to claim 2, wherein the weight ratio of iron, zirconium and boron is (0.17-0.67) calculated by oxide: (1-2): (2.1-7).

4. The method for preparing the boric acid modified iron-zirconium shape-selective catalyst according to claim 2, wherein the calcination time in the step (2) is 4-10 h.

5. The use of the boric acid modified iron zirconium shape selective catalyst of claim 1 in a reaction process for the high selective production of 2-alkyl anthracenes by anthracene alkylation.